Metin Kumlu | Çukurova University (original) (raw)

Papers by Metin Kumlu

Turkish Journal of Biology, Feb 25, 1999

This paper reviews the latest findings in larval feeding and digestion of decapod crustacean larv... more This paper reviews the latest findings in larval feeding and digestion of decapod crustacean larvae. The live feeds and manufactured feeds are discussed in relation with the digestive capability of various decapod crustacean larvae. Although some larvae such as penaeid shrimps are successfully cultured on artifical diets, most of larval decapod crustaceans are still heavily dependent on live organisms as food (i. e. micro-algae, Artemia). Studies with free-living nematodes as an alternative live feed for penaeid larvae are encouraging. Latest findings have demonstrated that omnivorous larvae (e.g. protozoeal stages of penaeids, Artemia, copepods) have high levels of proteolytic enzymes and a short gasto-evacuation time that enable these larvae to successfully survive on formulated diets. The digestive enzyme levels in carnivorous larvae (e.g. caridean larvae, lobster larvae), however, is so low that they cannot feed on artificial diets and require easily digestible prey in order to survive. Omnivorous larvae (e.g. crab larvae, mysis stages of penaeids) possess an intermediate level of digestive enzymes and are capable of utilising zooplankton, mikroalgae or even manufactured feeds. It appears that, in order to replace live feeds with artificial feeds for a wider range of crustaceans, the feeds must be made more digestible or digestive enzymes must be incorporated into the feeds.

DergiPark (Istanbul University), Dec 1, 1998

Abstract: In this study, the potential of nematodes as an alternative live feed for the omnivorou... more Abstract: In this study, the potential of nematodes as an alternative live feed for the omnivorous larva of Penaeus indicus (Crustacea: Penaeidae) and the carnivorous larvae of Macrobrachium rosenbergii and Palaemon elegans (Crustacea: Palaemonidae) was ...

Aquaculture, Aug 1, 2018

The purpose of this study was to determine the optimal stocking density, effects of tubifex (Tubi... more The purpose of this study was to determine the optimal stocking density, effects of tubifex (Tubifex tubifex) feeding and monosex culture on growth performance of guppy (Poecilia reticulata) in a recirculation system. Three separate experiments were conducted in 200-L cylindrical fiberglass tanks, at 1.5/h water turnover rate at 26°C water temperature. In Experiment 1, the fish (2.71 cm and 0.21 g) reached 4.56-4.99 cm length and 1.28-1.83 g weight at the at end of the culture period of 100 days in four stocking densities (1, 2, 3 and 4 fish/L), and 3 fish/L was found to be the optimal density under the present experimental conditions. In Experiment 2, the fish (2.68 cm and 0.20 g) were fed four different tubifex feeding frequencies (0, 1, 2 and 3 days/week) during a rearing period of 80 days. The growth of fish was increased (4.25-4.47 cm and 0.96-1.26 g) depending on the feeding frequency of tubifex, and the best growth was obtained in 3 days/week tubifex feeding (P < 0.05). In Experiment 3, the fish (3.20 cm and 0.27 g) were found to grow significantly better in monosex culture (4.47 cm, 1.09 g) than in the mixed culture (4.32 cm, 1.01 g) during the rearing period of 80 days. Also, in both culture types, the growth performance of females was about twice that of males (P < 0.05). In all the three trials, the fish reached to marketable size in as short as 80-100 days with very high survival rates (97-99%) even under the high stocking density of 3 fish/L. The present results are very promising in terms of providing higher yields per unit area as well as raising guppies in subtropical and even temperate climatic regions using closed RAS culture systems that can be applied worldwide.

Aquaculture, Feb 1, 2019

Thermal tolerance parameters of thirteen ornamental fish species (Carassius auratus, Cyprinus

Journal of the Marine Biological Association of the United Kingdom, Feb 1, 1997

Trypsin-like enzyme activity of the larvae of two planktonic predatory crustaceans, Homarus gamma... more Trypsin-like enzyme activity of the larvae of two planktonic predatory crustaceans, Homarus gammants and Nqphrops norvegicus (Decapoda: Nephropidae) and the omnivorous larvae of Carcinus maenas (Decapoda: Brachyura) were investigated at each larval stage until metamorphosis. Two copepods, herbivorous or omnivorous grazers, Centropages typicus and Temora longicornis (Copepoda: Calanoidae) were also investigated for this enzyme. A comparison of trypsin-like activity in these and other decapod larvae shows a pattern with high levels in herbivores, low levels in carnivores and intermediate levels in omnivores. Herbivorous planktonic crustaceans appear to rely on high digestive enzyme activities to extract nutrients from less digestible algae or particulates, whereas carnivorous larvae have limited enzymatic capacity as they feed at higher trophic levels upon large and easily digestible prey. Omnivorous Carcinus maenas larvae have intermediate levels of digestive enzymes and are able to transfer between herbivorous and omnivorous feeding.

This paper reviews the latest findings in larval feeding and digestion of decapod crustacean larv... more This paper reviews the latest findings in larval feeding and digestion of decapod crustacean larvae. The live feeds and manufactured feeds are discussed in relation with the digestive capability of various decapod crustacean larvae. Although some larvae such as penaeid shrimps are successfully cultured on artifical diets, most of larval decapod crustaceans are still heavily dependent on live organisms as food (i. e. micro-algae, Artemia). Studies with free-living nematodes as an alternative live feed for penaeid larvae are encouraging. Latest findings have demonstrated that omnivorous larvae (e.g. protozoeal stages of penaeids, Artemia, copepods) have high levels of proteolytic enzymes and a short gasto-evacuation time that enable these larvae to successfully survive on formulated diets. The digestive enzyme levels in carnivorous larvae (e.g. caridean larvae, lobster larvae), however, is so low that they cannot feed on artificial diets and require easily digestible prey in order to survive. Omnivorous larvae (e.g. crab larvae, mysis stages of penaeids) possess an intermediate level of digestive enzymes and are capable of utilising zooplankton, mikroalgae or even manufactured feeds. It appears that, in order to replace live feeds with artificial feeds for a wider range of crustaceans, the feeds must be made more digestible or digestive enzymes must be incorporated into the feeds.

Turkish Journal of Fisheries and Aquatic Sciences, Sep 1, 2015

The effects of four different rearing temperatures (15, 18, 21 and 24ºC) on reversed asymmetry an... more The effects of four different rearing temperatures (15, 18, 21 and 24ºC) on reversed asymmetry and larval development in the hatchery-reared larvae of the flounder, Platichthys flesus luscus, were investigated in this study. Incidence of reversed asymmetry (sinistral forms) were found to be 13.0, 10.4, 11.6 and 21.3% at 15, 18, 21 and 24ºC, respectively. The sinistrality rate was not affected by temperature between 15°C and 21°C, while this incidence was significantly higher at 24°C (P<0.05).

In this study, the effects of synthetic astaxanthin and red pepper on the pigmentation of rainbow... more In this study, the effects of synthetic astaxanthin and red pepper on the pigmentation of rainbow trout Oncorhynchus mykiss were investigated. The fish (167 g) were fed three diets: Diet A (control diet with no addition of carotenoids), Diet B (75 mg/kg synthetic astaxanthin added) and Diet C (5% red pepper supplemented) for 20, 40 and 60 days. Regardless of the experimental period the highest and lowest total carotenoid deposition in the fillet of the fish were found in fish fed Diet B (8.12 mg/kg) and Diet A (0.62 mg/kg), respectively (p0.05). Addition of 75 mg/kg astaxanthin (Diet B) increased the total cost of the feed by 15%, whereas addition of 5% red pepper (Diet C) to obtain 75 mg/kg of total carotenoid increased the cost by 14%

Turkish Journal of Fisheries and Aquatic Sciences, Nov 8, 2019

This study was performed to assess the combined effects of three salinities (0, 20 and 38 ppt) an... more This study was performed to assess the combined effects of three salinities (0, 20 and 38 ppt) and three acclimation temperatures (15, 20 and 25°C) on growth performance, proximate composition and thermal tolerance of European Sea Bass (32 g) inhabiting southern parts of the Mediterranean Sea. Highest fish final weight (83.8 g) was achieved at 25°C in freshwater (FW). Specific growth rate (SGR) at 25°C was about twice higher than that at 15°C, while 20°C promoted an intermediate growth. The fish cultured in FW at 25°C displayed consistently lower FCR and better SGR than those in full strength seawater (SW). Salinity had strong influence on fillet protein and lipid compositions. Highest lipid content (14.9%) was found in fish held in brackish water (20 ppt), and the fish held in SW had the lowest lipid content. CTMin and CTMax values ranged from 3.26°C to 7.33°C and from 31.81°C to 36.68°C, respectively. The thermal tolerance results indicated that European sea bass is more sensitive to high rather than low temperatures. These results suggested that this species can be farmed in stagnant SW deep ponds with high ambient temperatures during hot summer months in southern parts of the Mediterranean. During cold winter months, however, this fish can be successfully cultured in low salinities or even in FW.

Larva besleme çal›flmalar›n›n temel amaçlardan birisi de, yüksek bir larva yaflama ve h›zl› bir b... more Larva besleme çal›flmalar›n›n temel amaçlardan birisi de, yüksek bir larva yaflama ve h›zl› bir büyüme oran› sa¤layabilen, ayn› zamanda ekonomik ve kullan›m› pratik olan yem kaynaklar› gelifltirmektir. Halen, karides larva beslemede en yayg›n olarak kullan›lan yemler, özellikle canl› yemlerden olan mikro-algler ve zooplanktondan Artemia'd›r. Omnivor beslenme özelli¤ine sahip olan penaeid karidesler, yayg›n olarak, besin keselerini bitirdikten sonra, protozoea (PZ) döneminde mikroalglerle, mysis (M) ve postlarval (PL) dönemlerin bafllar›nda ise Artemia ile beslenirler (1, 2). Karnivor beslenme özelli¤i gösteren ve palaemonidae familyas›na ait olan tatl›su karidesinin (Macrobrachium rosenbergii) larvalar› ile Palaemon elegans larvalar› ise do¤rudan Artemia ile beslenirler (3).

This study investigates the factors affecting larval and postlarval survival and growth of some d... more This study investigates the factors affecting larval and postlarval survival and growth of some de capod crustaceans with special emphasis on diets. Investigations were concentrated on the influence o live and artificial diets on larval growth, survival, development and trypsM activity of a cominerciall, important marine penaeid shrimp Penaeus indicus and a freshwater prawn Macrobrachium rosenber gij. In addition, feeding behaviour, gastroevacuation time, trypsM activity of other decapod species wen also studied. Live mixed microalgae Tetraselmis chuii and Skeletonema costatum at 60-70 cells PI-1 promote( highest larval survival, fastest growth and development in P. indicus in comparison to single algal spe cies. Rhinomonas reticulata neither alone nor in combination with other algal species was suitable a! food for the shrimp larvae, A water salinity (S) of 25 ppt was optimal for larval and postlarval cultun of this penaeid species. Postlarvae (PL) of P. indicus reared at lower salinities between PL7 and PL& (20-30 ppt) had a significantly (P<0.05) higher survival and a better growth than those at higher wate salinities. Early PL resisted sudden salinity change of 10 ppt, but required an adaptation period fo greater salinity changes, 10 ppt S was lethal to animals at around PL40-45. A free-living nematode Panagrellus redivivus was found to be a suitable alternative for live algai and Artemia in the culture of P. indicus. The nematodes gave good survival, but lower growth than al gaelArtemia from PZI to PLI. Larval growth and survival were significantly improved when the larvai were fed on either nematodes plus algal co-feeds or liPid-enriched nematodes. Pigmented- (astaxanthin nematodes also improved survival and colour of P. indicus larvae in comparison to non-pigmented ones Conventional live diets were also completely replaced using microencapsulated diets (MED) fo the culture of P. indicus, Like the nematodes, MED as a sole feed resulted In lower survival, slowe growth and development in comparison to algaelArtemia. Addition of 15 cells gl-1 frozen algae signifi cantly improved growth and survival during larval development. The larvae fed MED plus algal co feeds had significantly (P<0.05) higher trypsm activity than those fed MED as a sole feed. Similarly provision of 15 cells gl-' algae with nematodes for only 24h or 48h resulted in significant increase H trypsin activity and improved survival and growth to levels comparable to those obtained from al gaelArtemia. It appears that the presence of an algal diet is necessary to induce larval trypsin activity Mi P. indicus at early protozoeal stages, but algae do not influence trypsin at mysts stages. Results sugges that both nematodes and formulated diets lack gut enzyme stimulants and are less digestible than al gaelArtemia diets. When freeze-dried algal materials were incorporated into MED, it was found tha algal substances which trigger larval digestive enzymes were retained within the capsules. Whether thi will improve growth and survival of penaeid larvae remains to be examined. In contrast to penaeid larvae, a complete replacement of live Artemia with nematodes or artificia diets was not possible for the culture of caridean M rosenbergii and PaIdemon elegans larvae. Fo both species, only a partial replacement was achieved from Z4/5 to metamorphosis by using formulateA diets. It was found that these larvae have very low trypsin activity levels between ZI and Z4/5, but th, levels increase sharply afterwards, coinciding with a vast increase in the hepatopancreas. This sharl increase in digestive enzyme activities and longer food retention time enable these larvae to survive oj less digestible formulated diets. A comparison of specific trypsin activity in several larval decapod crustaceans shows a pattein with high levels in herbivores, low levels in carnivores and intermediate levels M omnivores. Herbivor penaeid larvae (P. indicus) and copepods (Temora longicornis and Centropages typicus) rely on hig digestive enzyme activities to extract nutrients from less digestible algae, whereas carnivorous larvaE the lobsters (Homarus gammarus and Nephrops norvegicus) and carideans (M. rosenbergii and .1 elegans) have limited enzymatic capacity and hence require large and easily digestible prey, but rests long starvation periods. Omnivorous mysis penaeid larvae and Carcinus maenas have intermediat levels of digestive enzymes and are able to transfer from herbivorous to omnivorous feeding. To datE only decapod larvae which show high trypsm activity can be successfidly reared to metamorphosis o: formulated feeds. Inclusion of algal material, as a gut enzyme stimulant, for penaeid protozoeal stage and pre-digested ingredients for later stages into feeds are proposed.

DergiPark (Istanbul University), Feb 1, 1998

This study was conducted to compare the suitability of three microalgal species (Tetraselmis chui... more This study was conducted to compare the suitability of three microalgal species (Tetraselmis chuii, Skeletonema costatum and Rhinomonas reticulata), both individually and in combination, as food for Penaeus indicus during larval culture. To determine the best feeding density, each alga was fed to protozoea 1 (PZI) larvae from 10 to 80 cells µL-1. The best algal-cell density, promoting the highest survival rate, greatest growth and fastest larval development, was obtained at 60-70 cells µL-1 with a combination of T. chuii and S. costatum. Low cell densities (10-20 cells µL-1) were not effective. The diatom S. costatum produced better larval survival and growth than those of the flagellates (P<0.05). R. reticulata, both individually and in combination with the other algal species, was not suitable for the culture of P. indicus at any of the cell densities tested. The addition of algae while feeding on Artemia during the mysis stages did not produce better results than feeding only on Artemia (P>0.05). These results demonstrate that P. indicus PZI larvae, at 28˚C and 25ppt salinity, can be reared successfully on the mixed algal feed of T. chuii (25 cells µL-1) and S. castatum (35 cells µL-1) together with five Artemia nauplii µL-1 from MI onwards until metamorphosis in only 6-7 days.

Turkish Journal of Fisheries and Aquatic Sciences

A total of 300 juvenile crayfish (13.0±0.03 g) were randomly distributed among 5 dietary groups (... more A total of 300 juvenile crayfish (13.0±0.03 g) were randomly distributed among 5 dietary groups (n=60, 3 replicates) held within 15×500 L-1 fiberglass tanks connected to a recirculation system (RAS), at 20 crayfish per tank. Each group was fed for 12 weeks one of five experimental diets where the main protein sources were: 1) control, fish-meal-based diet (FM, 48% of the diet); 2) 10% FM + 52.5% poultry by-product meal (PoM); 3) 34.5% soybean meal + 34.5% corn gluten meal (Pmix); 4) 34.5% PoM + 32.soybean/corn gluten meal mix (PoM/Pmix); and 5) 10% FM + 27.5% soybean + 27.5% corn gluten meal (FM/Pmix). The results demonstrated that there were no significant differences among diets in terms of growth and feed utilization efficiency. Muscle amino acid profile of redclaw crayfish fed the FM diet had the highest level of total essential amino acids, followed by FM/PMix, Pmix, PoM/Pmix, and PoM diets. Particularly, in all experimental groups, the highest essential amino acids (EAA) were ...

Turkish Journal of …, 2006

The pigmentation level of an aquatic animal may be an important factor affecting its market value... more The pigmentation level of an aquatic animal may be an important factor affecting its market value and may also directly indicate its healthiness and quality (1). The most effective carotenoid responsible for pigmentation in shrimps is astaxanthin (2). It is well known that carotenoids are ...

Turkish Journal of Fisheries and Aquatic Sciences

The first aim of the present study was to determine appropriate artemia enrichment levels by usin... more The first aim of the present study was to determine appropriate artemia enrichment levels by using Aurantiochytrium mangrovei FIKU008 served as DHA enrichment source and secondly to test the effects of enriched-Artemia on growth and survival during the early larval stages(M1-PL7) of Penaeus semisulcatus. In the 1st experiment, four different enrichment levels of AUR (0.0,0.6,0.8 and 1.0g/L) against a control commercial solution (S-presso) were tested for 12/24-hours enrichment while in the 2nd experiment, three levels (0.0, 0.6 and 0.8g/L) of AUR enriched-Artemia were fed to larval stages. At the end of both enrichments, DHA and EPA levels were found to be significantly enhanced by using AUR at 0.6 and 0.8g/L. In the 2nd experiment, fatty acid composition of the PL was significantly affected by AUR and the PL fed with enriched diets showed higher n-3 LC-PUFA accumulation in their tissues. The larvae grown from M1 to PL7 displayed higher survivals and growth in the enriched AUR-group...

Turk J Zool, 2005

Abstract: The effects of 3 hormones, HCG, LH-RH and serotonin (5-HT), on maturation and spawning ... more Abstract: The effects of 3 hormones, HCG, LH-RH and serotonin (5-HT), on maturation and spawning of Penaeus semisulcatus de Hann, 1844 were investigated in 2 experiments in this study. The experiments were carried out in round (4 m diameter) fiberglass tanks for 50 days. In ...

Yaşama ve büyüme oranları açısından, düşük tuzluluklarla kıyaslandığında, P. semisulcatus post-la... more Yaşama ve büyüme oranları açısından, düşük tuzluluklarla kıyaslandığında, P. semisulcatus post-larvaları (PL), PL20 ve PL60 dönemleri arasında, yüksek tuzluluklarda daha iyi bir performans göstermişlerdir. Yüksek tuzluluklarda (%o30-40) deneme sonuna kadar yaşayanların yüzdeleri (%19-23) düşük tuzluluklardakinden (0.05). Tuzluluğun artması biyomasın 0.020 g'dan (%o 10'da) 0.317 g'a (%o40'ta) çıkmasına neden olmuştur (P 0.05). A rise in salinity resulted in an increase in the biomass from 0.020 g at 10 ppt to 0.317 g at 40 ppt (P < 0.05). Optimum salinity for the nursery culture of P. semisulcatus PLs appeared to be about 40 ppt at 28 circ\circcircC. Hence, the results of this study demonstrate that P. semisulcatus inhabiting the Mediterranean Sea is not a good candidate for culture in waters of low salinity

Bu çalışma, iki ayrı deneme halinde, Penaeus semisulcatus’un ön-semirtme dönemindeki optimum su s... more Bu çalışma, iki ayrı deneme halinde, Penaeus semisulcatus’un ön-semirtme dönemindeki optimum su sıcaklığının belirlenmesi ve substratın büyüme ve yaşama oranı üzerindeki etkisini belirlemek amacıyla yapılmıştır. Altı hafta sonunda, 22, 24, 26, 30 ve 34°C’de elde edilen yaşama oranları sırasıyla %52, 46, 70, 30 ve 40 olarak bulunmuştur. Total boyca en yüksek (2,76 mm/hafta) ve en düşük (0,43-0,49 mm/hafta) büyüme oranları 34°C ve 22-24°C’de yetiştirilen postlarvalarda (PL) bulunmuştur. 26°C ve 30°C’lerdeki haftalık büyüme oranları sırasıyla 1,03 mm ve 1,75 mm’dir. Sıcaklığın 22°C’den 34°C’ye çıkmasıyla deneme sonu bireysel ağırlık 55 mg’dan 285 mg’a çıkmıştır (yaklaşık 5 kat artış). 22, 24 ve 26°C’de yetiştirilen PL’lerde büyüme farklı bulunmamıştır (P>0.05). Ağırlıkça büyüme oranı 34°C’de 432 mg/hafta ve 22-24°C’de 58-68 mg/hafta olarak belirlenmiştir. 34°C’de büyütülen PL’ler 22-24°C’dekilere göre 6-7 kat daha hızlı büyümüşlerdir. 34°C’de elde edilen ürün (5,7 g), 22°C’dekinden ...

Bu çalışmada üç farklı hormon, HCG, LH-RH ve Serotonin (S-HT)'in Penaeus semisulcatus de Hann... more Bu çalışmada üç farklı hormon, HCG, LH-RH ve Serotonin (S-HT)'in Penaeus semisulcatus de Hann, 1844'un gonad gelişimi ve yumurtlaması üzerine etkileri iki denemede araştırılmıştır. Denemeler yuvarlak (4 m çapında) fiberglas tanklarda 50 günlük sürede gerçekleştirilmiştir. Birinci denemede 3 farklı dozda HCG enjekte edilen [1, 2 ve 3 IU g−1g^{-1}g−1 Vücut Ağırlığı (VA)] karideslerin üreme performansı serum fizyolojik solüsyon (%0,85 NaCl) enjekte edilen grup ve göz sapı kesilen grup ile karşılaştırmıştır, ikinci denemede 3 farklı LH-RH (0,01, 0,1 ve 0,2 mg g−1g^{-1}g−1 VA) ve Serotonin (20, 50 ve 100 pg g−1g^{-1}g−1 VA) enjeksiyonu yapılan karideslerin üreme performansı serum fizyolojik solüsyon enjekte edilen grup ve gözsapı kesimi yapılan grup ile karşılaştırılmışlar. Birinci denemede kabuk değiştirme döngüsü muameleler arasında istatistik! o.larak farklılık göstermemiştir (P > 0,05). En fazla yumurtlama gözsapı kesilen gruptan elde edilmiş ve bunu sırasıyla 3 IU g−1g^{-1}g−1 (iki yumur...

Response of proximate and fatty acid (FA) composition of the green tiger shrimp Penaeus semisulca... more Response of proximate and fatty acid (FA) composition of the green tiger shrimp Penaeus semisulcatus in relation to changing water temperatures during over wintering (for 8-weeks at 11-16°C) and then refeeding periods (at 28°C for a further 2-weeks) was investigated in this study. The shrimps did not appear to need to catabolise their either body proteins or lipids during the overwintering period, as the feeding was not ceased completely. While muscle protein, ash and dry matter compositions of the shrimps did not change by changing temperature, lipid increased from 1% during the overwintering period to 1.2% during the recovery period (P<0.01). Saturated FAs (SFA), mono-unsaturated FAs (MUFA), and partially poly-unsaturated FAs (n-6 PUFA) declined, on the contrary, n-3 PUFA significantly rose in the muscle and hepatopacreas during the cold exposure. Shrimps tended to consume especially SFA and, to a lesser degree, MUFA under sub-optimal conditions (P<0.01). PUFA and LC-PUFA ap...

Turkish Journal of Biology, Feb 25, 1999

This paper reviews the latest findings in larval feeding and digestion of decapod crustacean larv... more This paper reviews the latest findings in larval feeding and digestion of decapod crustacean larvae. The live feeds and manufactured feeds are discussed in relation with the digestive capability of various decapod crustacean larvae. Although some larvae such as penaeid shrimps are successfully cultured on artifical diets, most of larval decapod crustaceans are still heavily dependent on live organisms as food (i. e. micro-algae, Artemia). Studies with free-living nematodes as an alternative live feed for penaeid larvae are encouraging. Latest findings have demonstrated that omnivorous larvae (e.g. protozoeal stages of penaeids, Artemia, copepods) have high levels of proteolytic enzymes and a short gasto-evacuation time that enable these larvae to successfully survive on formulated diets. The digestive enzyme levels in carnivorous larvae (e.g. caridean larvae, lobster larvae), however, is so low that they cannot feed on artificial diets and require easily digestible prey in order to survive. Omnivorous larvae (e.g. crab larvae, mysis stages of penaeids) possess an intermediate level of digestive enzymes and are capable of utilising zooplankton, mikroalgae or even manufactured feeds. It appears that, in order to replace live feeds with artificial feeds for a wider range of crustaceans, the feeds must be made more digestible or digestive enzymes must be incorporated into the feeds.

DergiPark (Istanbul University), Dec 1, 1998

Abstract: In this study, the potential of nematodes as an alternative live feed for the omnivorou... more Abstract: In this study, the potential of nematodes as an alternative live feed for the omnivorous larva of Penaeus indicus (Crustacea: Penaeidae) and the carnivorous larvae of Macrobrachium rosenbergii and Palaemon elegans (Crustacea: Palaemonidae) was ...

Aquaculture, Aug 1, 2018

The purpose of this study was to determine the optimal stocking density, effects of tubifex (Tubi... more The purpose of this study was to determine the optimal stocking density, effects of tubifex (Tubifex tubifex) feeding and monosex culture on growth performance of guppy (Poecilia reticulata) in a recirculation system. Three separate experiments were conducted in 200-L cylindrical fiberglass tanks, at 1.5/h water turnover rate at 26°C water temperature. In Experiment 1, the fish (2.71 cm and 0.21 g) reached 4.56-4.99 cm length and 1.28-1.83 g weight at the at end of the culture period of 100 days in four stocking densities (1, 2, 3 and 4 fish/L), and 3 fish/L was found to be the optimal density under the present experimental conditions. In Experiment 2, the fish (2.68 cm and 0.20 g) were fed four different tubifex feeding frequencies (0, 1, 2 and 3 days/week) during a rearing period of 80 days. The growth of fish was increased (4.25-4.47 cm and 0.96-1.26 g) depending on the feeding frequency of tubifex, and the best growth was obtained in 3 days/week tubifex feeding (P < 0.05). In Experiment 3, the fish (3.20 cm and 0.27 g) were found to grow significantly better in monosex culture (4.47 cm, 1.09 g) than in the mixed culture (4.32 cm, 1.01 g) during the rearing period of 80 days. Also, in both culture types, the growth performance of females was about twice that of males (P < 0.05). In all the three trials, the fish reached to marketable size in as short as 80-100 days with very high survival rates (97-99%) even under the high stocking density of 3 fish/L. The present results are very promising in terms of providing higher yields per unit area as well as raising guppies in subtropical and even temperate climatic regions using closed RAS culture systems that can be applied worldwide.

Aquaculture, Feb 1, 2019

Thermal tolerance parameters of thirteen ornamental fish species (Carassius auratus, Cyprinus

Journal of the Marine Biological Association of the United Kingdom, Feb 1, 1997

Trypsin-like enzyme activity of the larvae of two planktonic predatory crustaceans, Homarus gamma... more Trypsin-like enzyme activity of the larvae of two planktonic predatory crustaceans, Homarus gammants and Nqphrops norvegicus (Decapoda: Nephropidae) and the omnivorous larvae of Carcinus maenas (Decapoda: Brachyura) were investigated at each larval stage until metamorphosis. Two copepods, herbivorous or omnivorous grazers, Centropages typicus and Temora longicornis (Copepoda: Calanoidae) were also investigated for this enzyme. A comparison of trypsin-like activity in these and other decapod larvae shows a pattern with high levels in herbivores, low levels in carnivores and intermediate levels in omnivores. Herbivorous planktonic crustaceans appear to rely on high digestive enzyme activities to extract nutrients from less digestible algae or particulates, whereas carnivorous larvae have limited enzymatic capacity as they feed at higher trophic levels upon large and easily digestible prey. Omnivorous Carcinus maenas larvae have intermediate levels of digestive enzymes and are able to transfer between herbivorous and omnivorous feeding.

This paper reviews the latest findings in larval feeding and digestion of decapod crustacean larv... more This paper reviews the latest findings in larval feeding and digestion of decapod crustacean larvae. The live feeds and manufactured feeds are discussed in relation with the digestive capability of various decapod crustacean larvae. Although some larvae such as penaeid shrimps are successfully cultured on artifical diets, most of larval decapod crustaceans are still heavily dependent on live organisms as food (i. e. micro-algae, Artemia). Studies with free-living nematodes as an alternative live feed for penaeid larvae are encouraging. Latest findings have demonstrated that omnivorous larvae (e.g. protozoeal stages of penaeids, Artemia, copepods) have high levels of proteolytic enzymes and a short gasto-evacuation time that enable these larvae to successfully survive on formulated diets. The digestive enzyme levels in carnivorous larvae (e.g. caridean larvae, lobster larvae), however, is so low that they cannot feed on artificial diets and require easily digestible prey in order to survive. Omnivorous larvae (e.g. crab larvae, mysis stages of penaeids) possess an intermediate level of digestive enzymes and are capable of utilising zooplankton, mikroalgae or even manufactured feeds. It appears that, in order to replace live feeds with artificial feeds for a wider range of crustaceans, the feeds must be made more digestible or digestive enzymes must be incorporated into the feeds.

Turkish Journal of Fisheries and Aquatic Sciences, Sep 1, 2015

The effects of four different rearing temperatures (15, 18, 21 and 24ºC) on reversed asymmetry an... more The effects of four different rearing temperatures (15, 18, 21 and 24ºC) on reversed asymmetry and larval development in the hatchery-reared larvae of the flounder, Platichthys flesus luscus, were investigated in this study. Incidence of reversed asymmetry (sinistral forms) were found to be 13.0, 10.4, 11.6 and 21.3% at 15, 18, 21 and 24ºC, respectively. The sinistrality rate was not affected by temperature between 15°C and 21°C, while this incidence was significantly higher at 24°C (P<0.05).

In this study, the effects of synthetic astaxanthin and red pepper on the pigmentation of rainbow... more In this study, the effects of synthetic astaxanthin and red pepper on the pigmentation of rainbow trout Oncorhynchus mykiss were investigated. The fish (167 g) were fed three diets: Diet A (control diet with no addition of carotenoids), Diet B (75 mg/kg synthetic astaxanthin added) and Diet C (5% red pepper supplemented) for 20, 40 and 60 days. Regardless of the experimental period the highest and lowest total carotenoid deposition in the fillet of the fish were found in fish fed Diet B (8.12 mg/kg) and Diet A (0.62 mg/kg), respectively (p0.05). Addition of 75 mg/kg astaxanthin (Diet B) increased the total cost of the feed by 15%, whereas addition of 5% red pepper (Diet C) to obtain 75 mg/kg of total carotenoid increased the cost by 14%

Turkish Journal of Fisheries and Aquatic Sciences, Nov 8, 2019

This study was performed to assess the combined effects of three salinities (0, 20 and 38 ppt) an... more This study was performed to assess the combined effects of three salinities (0, 20 and 38 ppt) and three acclimation temperatures (15, 20 and 25°C) on growth performance, proximate composition and thermal tolerance of European Sea Bass (32 g) inhabiting southern parts of the Mediterranean Sea. Highest fish final weight (83.8 g) was achieved at 25°C in freshwater (FW). Specific growth rate (SGR) at 25°C was about twice higher than that at 15°C, while 20°C promoted an intermediate growth. The fish cultured in FW at 25°C displayed consistently lower FCR and better SGR than those in full strength seawater (SW). Salinity had strong influence on fillet protein and lipid compositions. Highest lipid content (14.9%) was found in fish held in brackish water (20 ppt), and the fish held in SW had the lowest lipid content. CTMin and CTMax values ranged from 3.26°C to 7.33°C and from 31.81°C to 36.68°C, respectively. The thermal tolerance results indicated that European sea bass is more sensitive to high rather than low temperatures. These results suggested that this species can be farmed in stagnant SW deep ponds with high ambient temperatures during hot summer months in southern parts of the Mediterranean. During cold winter months, however, this fish can be successfully cultured in low salinities or even in FW.

Larva besleme çal›flmalar›n›n temel amaçlardan birisi de, yüksek bir larva yaflama ve h›zl› bir b... more Larva besleme çal›flmalar›n›n temel amaçlardan birisi de, yüksek bir larva yaflama ve h›zl› bir büyüme oran› sa¤layabilen, ayn› zamanda ekonomik ve kullan›m› pratik olan yem kaynaklar› gelifltirmektir. Halen, karides larva beslemede en yayg›n olarak kullan›lan yemler, özellikle canl› yemlerden olan mikro-algler ve zooplanktondan Artemia'd›r. Omnivor beslenme özelli¤ine sahip olan penaeid karidesler, yayg›n olarak, besin keselerini bitirdikten sonra, protozoea (PZ) döneminde mikroalglerle, mysis (M) ve postlarval (PL) dönemlerin bafllar›nda ise Artemia ile beslenirler (1, 2). Karnivor beslenme özelli¤i gösteren ve palaemonidae familyas›na ait olan tatl›su karidesinin (Macrobrachium rosenbergii) larvalar› ile Palaemon elegans larvalar› ise do¤rudan Artemia ile beslenirler (3).

This study investigates the factors affecting larval and postlarval survival and growth of some d... more This study investigates the factors affecting larval and postlarval survival and growth of some de capod crustaceans with special emphasis on diets. Investigations were concentrated on the influence o live and artificial diets on larval growth, survival, development and trypsM activity of a cominerciall, important marine penaeid shrimp Penaeus indicus and a freshwater prawn Macrobrachium rosenber gij. In addition, feeding behaviour, gastroevacuation time, trypsM activity of other decapod species wen also studied. Live mixed microalgae Tetraselmis chuii and Skeletonema costatum at 60-70 cells PI-1 promote( highest larval survival, fastest growth and development in P. indicus in comparison to single algal spe cies. Rhinomonas reticulata neither alone nor in combination with other algal species was suitable a! food for the shrimp larvae, A water salinity (S) of 25 ppt was optimal for larval and postlarval cultun of this penaeid species. Postlarvae (PL) of P. indicus reared at lower salinities between PL7 and PL& (20-30 ppt) had a significantly (P<0.05) higher survival and a better growth than those at higher wate salinities. Early PL resisted sudden salinity change of 10 ppt, but required an adaptation period fo greater salinity changes, 10 ppt S was lethal to animals at around PL40-45. A free-living nematode Panagrellus redivivus was found to be a suitable alternative for live algai and Artemia in the culture of P. indicus. The nematodes gave good survival, but lower growth than al gaelArtemia from PZI to PLI. Larval growth and survival were significantly improved when the larvai were fed on either nematodes plus algal co-feeds or liPid-enriched nematodes. Pigmented- (astaxanthin nematodes also improved survival and colour of P. indicus larvae in comparison to non-pigmented ones Conventional live diets were also completely replaced using microencapsulated diets (MED) fo the culture of P. indicus, Like the nematodes, MED as a sole feed resulted In lower survival, slowe growth and development in comparison to algaelArtemia. Addition of 15 cells gl-1 frozen algae signifi cantly improved growth and survival during larval development. The larvae fed MED plus algal co feeds had significantly (P<0.05) higher trypsm activity than those fed MED as a sole feed. Similarly provision of 15 cells gl-' algae with nematodes for only 24h or 48h resulted in significant increase H trypsin activity and improved survival and growth to levels comparable to those obtained from al gaelArtemia. It appears that the presence of an algal diet is necessary to induce larval trypsin activity Mi P. indicus at early protozoeal stages, but algae do not influence trypsin at mysts stages. Results sugges that both nematodes and formulated diets lack gut enzyme stimulants and are less digestible than al gaelArtemia diets. When freeze-dried algal materials were incorporated into MED, it was found tha algal substances which trigger larval digestive enzymes were retained within the capsules. Whether thi will improve growth and survival of penaeid larvae remains to be examined. In contrast to penaeid larvae, a complete replacement of live Artemia with nematodes or artificia diets was not possible for the culture of caridean M rosenbergii and PaIdemon elegans larvae. Fo both species, only a partial replacement was achieved from Z4/5 to metamorphosis by using formulateA diets. It was found that these larvae have very low trypsin activity levels between ZI and Z4/5, but th, levels increase sharply afterwards, coinciding with a vast increase in the hepatopancreas. This sharl increase in digestive enzyme activities and longer food retention time enable these larvae to survive oj less digestible formulated diets. A comparison of specific trypsin activity in several larval decapod crustaceans shows a pattein with high levels in herbivores, low levels in carnivores and intermediate levels M omnivores. Herbivor penaeid larvae (P. indicus) and copepods (Temora longicornis and Centropages typicus) rely on hig digestive enzyme activities to extract nutrients from less digestible algae, whereas carnivorous larvaE the lobsters (Homarus gammarus and Nephrops norvegicus) and carideans (M. rosenbergii and .1 elegans) have limited enzymatic capacity and hence require large and easily digestible prey, but rests long starvation periods. Omnivorous mysis penaeid larvae and Carcinus maenas have intermediat levels of digestive enzymes and are able to transfer from herbivorous to omnivorous feeding. To datE only decapod larvae which show high trypsm activity can be successfidly reared to metamorphosis o: formulated feeds. Inclusion of algal material, as a gut enzyme stimulant, for penaeid protozoeal stage and pre-digested ingredients for later stages into feeds are proposed.

DergiPark (Istanbul University), Feb 1, 1998

This study was conducted to compare the suitability of three microalgal species (Tetraselmis chui... more This study was conducted to compare the suitability of three microalgal species (Tetraselmis chuii, Skeletonema costatum and Rhinomonas reticulata), both individually and in combination, as food for Penaeus indicus during larval culture. To determine the best feeding density, each alga was fed to protozoea 1 (PZI) larvae from 10 to 80 cells µL-1. The best algal-cell density, promoting the highest survival rate, greatest growth and fastest larval development, was obtained at 60-70 cells µL-1 with a combination of T. chuii and S. costatum. Low cell densities (10-20 cells µL-1) were not effective. The diatom S. costatum produced better larval survival and growth than those of the flagellates (P<0.05). R. reticulata, both individually and in combination with the other algal species, was not suitable for the culture of P. indicus at any of the cell densities tested. The addition of algae while feeding on Artemia during the mysis stages did not produce better results than feeding only on Artemia (P>0.05). These results demonstrate that P. indicus PZI larvae, at 28˚C and 25ppt salinity, can be reared successfully on the mixed algal feed of T. chuii (25 cells µL-1) and S. castatum (35 cells µL-1) together with five Artemia nauplii µL-1 from MI onwards until metamorphosis in only 6-7 days.

Turkish Journal of Fisheries and Aquatic Sciences

A total of 300 juvenile crayfish (13.0±0.03 g) were randomly distributed among 5 dietary groups (... more A total of 300 juvenile crayfish (13.0±0.03 g) were randomly distributed among 5 dietary groups (n=60, 3 replicates) held within 15×500 L-1 fiberglass tanks connected to a recirculation system (RAS), at 20 crayfish per tank. Each group was fed for 12 weeks one of five experimental diets where the main protein sources were: 1) control, fish-meal-based diet (FM, 48% of the diet); 2) 10% FM + 52.5% poultry by-product meal (PoM); 3) 34.5% soybean meal + 34.5% corn gluten meal (Pmix); 4) 34.5% PoM + 32.soybean/corn gluten meal mix (PoM/Pmix); and 5) 10% FM + 27.5% soybean + 27.5% corn gluten meal (FM/Pmix). The results demonstrated that there were no significant differences among diets in terms of growth and feed utilization efficiency. Muscle amino acid profile of redclaw crayfish fed the FM diet had the highest level of total essential amino acids, followed by FM/PMix, Pmix, PoM/Pmix, and PoM diets. Particularly, in all experimental groups, the highest essential amino acids (EAA) were ...

Turkish Journal of …, 2006

The pigmentation level of an aquatic animal may be an important factor affecting its market value... more The pigmentation level of an aquatic animal may be an important factor affecting its market value and may also directly indicate its healthiness and quality (1). The most effective carotenoid responsible for pigmentation in shrimps is astaxanthin (2). It is well known that carotenoids are ...

Turkish Journal of Fisheries and Aquatic Sciences

The first aim of the present study was to determine appropriate artemia enrichment levels by usin... more The first aim of the present study was to determine appropriate artemia enrichment levels by using Aurantiochytrium mangrovei FIKU008 served as DHA enrichment source and secondly to test the effects of enriched-Artemia on growth and survival during the early larval stages(M1-PL7) of Penaeus semisulcatus. In the 1st experiment, four different enrichment levels of AUR (0.0,0.6,0.8 and 1.0g/L) against a control commercial solution (S-presso) were tested for 12/24-hours enrichment while in the 2nd experiment, three levels (0.0, 0.6 and 0.8g/L) of AUR enriched-Artemia were fed to larval stages. At the end of both enrichments, DHA and EPA levels were found to be significantly enhanced by using AUR at 0.6 and 0.8g/L. In the 2nd experiment, fatty acid composition of the PL was significantly affected by AUR and the PL fed with enriched diets showed higher n-3 LC-PUFA accumulation in their tissues. The larvae grown from M1 to PL7 displayed higher survivals and growth in the enriched AUR-group...

Turk J Zool, 2005

Abstract: The effects of 3 hormones, HCG, LH-RH and serotonin (5-HT), on maturation and spawning ... more Abstract: The effects of 3 hormones, HCG, LH-RH and serotonin (5-HT), on maturation and spawning of Penaeus semisulcatus de Hann, 1844 were investigated in 2 experiments in this study. The experiments were carried out in round (4 m diameter) fiberglass tanks for 50 days. In ...

Yaşama ve büyüme oranları açısından, düşük tuzluluklarla kıyaslandığında, P. semisulcatus post-la... more Yaşama ve büyüme oranları açısından, düşük tuzluluklarla kıyaslandığında, P. semisulcatus post-larvaları (PL), PL20 ve PL60 dönemleri arasında, yüksek tuzluluklarda daha iyi bir performans göstermişlerdir. Yüksek tuzluluklarda (%o30-40) deneme sonuna kadar yaşayanların yüzdeleri (%19-23) düşük tuzluluklardakinden (0.05). Tuzluluğun artması biyomasın 0.020 g'dan (%o 10'da) 0.317 g'a (%o40'ta) çıkmasına neden olmuştur (P 0.05). A rise in salinity resulted in an increase in the biomass from 0.020 g at 10 ppt to 0.317 g at 40 ppt (P < 0.05). Optimum salinity for the nursery culture of P. semisulcatus PLs appeared to be about 40 ppt at 28 circ\circcircC. Hence, the results of this study demonstrate that P. semisulcatus inhabiting the Mediterranean Sea is not a good candidate for culture in waters of low salinity

Bu çalışma, iki ayrı deneme halinde, Penaeus semisulcatus’un ön-semirtme dönemindeki optimum su s... more Bu çalışma, iki ayrı deneme halinde, Penaeus semisulcatus’un ön-semirtme dönemindeki optimum su sıcaklığının belirlenmesi ve substratın büyüme ve yaşama oranı üzerindeki etkisini belirlemek amacıyla yapılmıştır. Altı hafta sonunda, 22, 24, 26, 30 ve 34°C’de elde edilen yaşama oranları sırasıyla %52, 46, 70, 30 ve 40 olarak bulunmuştur. Total boyca en yüksek (2,76 mm/hafta) ve en düşük (0,43-0,49 mm/hafta) büyüme oranları 34°C ve 22-24°C’de yetiştirilen postlarvalarda (PL) bulunmuştur. 26°C ve 30°C’lerdeki haftalık büyüme oranları sırasıyla 1,03 mm ve 1,75 mm’dir. Sıcaklığın 22°C’den 34°C’ye çıkmasıyla deneme sonu bireysel ağırlık 55 mg’dan 285 mg’a çıkmıştır (yaklaşık 5 kat artış). 22, 24 ve 26°C’de yetiştirilen PL’lerde büyüme farklı bulunmamıştır (P>0.05). Ağırlıkça büyüme oranı 34°C’de 432 mg/hafta ve 22-24°C’de 58-68 mg/hafta olarak belirlenmiştir. 34°C’de büyütülen PL’ler 22-24°C’dekilere göre 6-7 kat daha hızlı büyümüşlerdir. 34°C’de elde edilen ürün (5,7 g), 22°C’dekinden ...

Bu çalışmada üç farklı hormon, HCG, LH-RH ve Serotonin (S-HT)'in Penaeus semisulcatus de Hann... more Bu çalışmada üç farklı hormon, HCG, LH-RH ve Serotonin (S-HT)'in Penaeus semisulcatus de Hann, 1844'un gonad gelişimi ve yumurtlaması üzerine etkileri iki denemede araştırılmıştır. Denemeler yuvarlak (4 m çapında) fiberglas tanklarda 50 günlük sürede gerçekleştirilmiştir. Birinci denemede 3 farklı dozda HCG enjekte edilen [1, 2 ve 3 IU g−1g^{-1}g−1 Vücut Ağırlığı (VA)] karideslerin üreme performansı serum fizyolojik solüsyon (%0,85 NaCl) enjekte edilen grup ve göz sapı kesilen grup ile karşılaştırmıştır, ikinci denemede 3 farklı LH-RH (0,01, 0,1 ve 0,2 mg g−1g^{-1}g−1 VA) ve Serotonin (20, 50 ve 100 pg g−1g^{-1}g−1 VA) enjeksiyonu yapılan karideslerin üreme performansı serum fizyolojik solüsyon enjekte edilen grup ve gözsapı kesimi yapılan grup ile karşılaştırılmışlar. Birinci denemede kabuk değiştirme döngüsü muameleler arasında istatistik! o.larak farklılık göstermemiştir (P > 0,05). En fazla yumurtlama gözsapı kesilen gruptan elde edilmiş ve bunu sırasıyla 3 IU g−1g^{-1}g−1 (iki yumur...

Response of proximate and fatty acid (FA) composition of the green tiger shrimp Penaeus semisulca... more Response of proximate and fatty acid (FA) composition of the green tiger shrimp Penaeus semisulcatus in relation to changing water temperatures during over wintering (for 8-weeks at 11-16°C) and then refeeding periods (at 28°C for a further 2-weeks) was investigated in this study. The shrimps did not appear to need to catabolise their either body proteins or lipids during the overwintering period, as the feeding was not ceased completely. While muscle protein, ash and dry matter compositions of the shrimps did not change by changing temperature, lipid increased from 1% during the overwintering period to 1.2% during the recovery period (P<0.01). Saturated FAs (SFA), mono-unsaturated FAs (MUFA), and partially poly-unsaturated FAs (n-6 PUFA) declined, on the contrary, n-3 PUFA significantly rose in the muscle and hepatopacreas during the cold exposure. Shrimps tended to consume especially SFA and, to a lesser degree, MUFA under sub-optimal conditions (P<0.01). PUFA and LC-PUFA ap...