Reproduction of the wedge sole (Dicologoglossa cuneata Moreau) in captivity: spawning parameters and influence of the natural temperature (original) (raw)
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Aquaculture International, 2008
The wedge sole is a target species in the fisheries of the Gulf of Cadiz (Spain). Having reared them to commercial size, we have studied reproduction and breeding in captivity of the wedge sole in this work here. The breeders adapt easily to captivity, and they can spawn in less than 1 year in captivity. The relative fecundity is relatively high, 1.06-2.33 Á 10 6 eggs kg À1 per spawning season (mean 1.6 ± 0.1). Larval SGR is high, 7.2 ± 0.2% day À1 (range 5.8-9.1), similar to other cultured flatfish species. In 1 year, some individuals reach market size and can release eggs, registering SGRs of 1.39-1.66% day À1 (mean 1.56 ± 0.01). This species presents some very different characteristics with respect to other farmed flatfishes (turbot, halibut and Senegal sole, mainly), so that it is necessary to develop new techniques to optimise its cultivation. In the present work, the first results are presented on the biology of the wedge sole in captivity.
Aquaculture, 2005
Senegal sole aquaculture is at present limited due to poor reproduction of captive breeders in many facilities. Temperature seems to play an important role in controlling reproduction of Solea senegalensis, and differences in temperature regimes followed by various hatcheries are likely to be responsible for lack of success in some of them. This work describes the reproduction of captive soles, held in facilities that used water at ambient temperature, from a marshy environment where this species naturally breeds. Acclimated sole breeders were kept for two consecutive years. The main spawning period occurred from February to May, with a secondary spawning in autumn. Total yearly fecundity ranged from 1.15Â10 6 to 1.65Â10 6 eggs kg À1 body weight. Of the total egg batches produced, only 5.4% corresponded to autumn spawns. The male population was found to produce sperm all year round, with a maximum proportion of 100% occurring in spring, and a minimum proportion of around 50% in summer. Females showed the more developed ovary stages from October to May, with partial regression in the summer months. During the main spawning period, eggs were produced between 46% and 69% of days. Spawning took place at temperatures from 13 to 23 8C, although higher fecundities (Pb0.05) occurred between 15 and 21 8C. Within the range between 17 and 20 8C, the mean number of spawned eggs was 29,600F21,600 eggs day À1 kg À1. Most of the eggs (65-73%) were produced after temperature increased up to 2.5 8C within 3 days prior to spawning. Mean egg fertilization was 63.1F17% (year 2002) and 44.9F18% (year 2003), and hatching rates varied from 69.7F24% (2002) to 56.5 F25% (2003). Weak correlations were found between either fertilization or hatching and fecundity, whereas a positive regression (Pb0.05) indicated that higher hatching rates were achieved when fertilization increased. A weak, but significantly (Pb0.05) positive correlation was found between egg fertilization and the spawning temperature. Present results indicate temperature is an important control factor for reproduction of S. senegalensis, and suggest it can be used to properly manage controlled captive reproduction of this species.
Aquaculture International, 2010
The weaning phase can be decisive in fish-culture viability. In this work, the relationship between the initial size and weaning success has been studied in wedge sole (Dicologoglossa cuneata). For each age (30, 50, and 70 days after hatching, DAH), two to three sizes were selected, and all were put on the same feeding schedule for 20 days. Each batch (three replicates) was sampled at 1, 10, and 20 days. Specific growth rate (SGR) and survival were compared at the end of the co-feeding period, after 10 days on dry feed only. The best results for survival and growth were found with the smallest larvae, and vice versa. The SGRs and survival rates recorded during the co-feeding period were higher (0.8-15.6 day -1 and 68.3-97.8%) than those from the dry-food phase (0.9-4.7 day -1 and 56.3-66.7%). Successful weaning (survival = 65% and SGR = 9.3 day -1 ) is possible with 30 DAH larvae (7.6-8.1 mm and 3.9-4.6 mg). In conclusion, the most effective weaning would be possible at 30 DAH, implying significant Artemia savings (25-50%).
Scientia Marina, 2006
Ichthyoplankton samples and hydrological data were obtained in an inshore area, between the mouths of the Rivers Guadalquivir and Guadiana (Gulf of Cádiz, SW Spain) during monthly surveys carried out from March 2002 to March 2003. Horizontal and temporal distributions of wedge sole (Dicologlossa cuneata) egg and larval abundances were analysed during this annual cycle in relation to environmental parameters. This area proved to be an important spawning and nursery ground for the species, which showed a winter-spring reproductive strategy with a long reproductive period lasting from autumn until early summer. Spawning areas were located in the shallowest waters (above 30 m depth) between the mouths of the Rives Guadiana and Tinto-Odiel, and to a lesser extent in the coastal zone between the mouths of the Rivers Tinto-Odiel and Guadalquivir. The spawning habitat was mainly determined by the distribution of the adults, the bathymetry and the temperature, and a preference for shallow and colder waters was observed. The inshore zone between the mouths of the Rivers Tinto-Odiel and Guadalquivir is the main nursery ground, with the greatest larval concentration and productivity in the area, due to the influence of the River Guadalquivir. The presence of recruits in this area may be linked to these favourable conditions for larval growth and survival.
GLOBEC Report, 2005
dissertation concerned nest parasitism of sunfi shes by minnows. These divergent areas of study prepared him for the diversity of scientifi c approaches he has used to understand and manage the coastal pelagic species off California. Initially, his research was concentrated on tuna and porpoise interaction in order to defi ne the behavior of tuna near fl otsam. Tropical tuna fi sheries now take advantage of the aggregation of tuna around artifi cial fl oating devices. Later, he became a laboratory scientist defi ning the progress of fi sh egg and larva development and particularly that of schooling and feeding behavior of aggregations of larvae preying on patches of motile plankton. Many of his publications concern the details of spawning and the importance of that knowledge in evaluating fi sh resources.
Aquaculture, 2002
This study was designed to determine the influence of different thermal conditions during an out-of-season reproductive cycle on gonad recrudescence, plasma steroid levels (testosterone and estradiol), vitellogenin (VTG) concentrations and spawning in Eurasian perch (Perca fluviatilis) females. The experiment was performed in 450-l square polyester indoor tanks located in two rooms equipped with controlled light and temperature devices. Four thermal regimes were tested with two different rates of cooling from 21 to 6°C, 3 weeks (3w) or 6 weeks (6w), and two different durations at 6°C, 3 months (3m) or 5 months (5m). The photoperiod was fixed at LD 12:12. A long cooling period (6w) resulted in greater gonadosomatic index (GSI) (3.6 F 0.5%) correlated with a larger oocyte diameter (787.9 F 25.1 mm). The plasma levels of testosterone (13.63 F 1.18 ng ml À 1) in the former groups were higher than in the short cooling period groups (6.82 F 0.9 ng ml À 1). A longer duration at 6°C (5m) resulted in higher GSI (14.8 F 1%), plasma testosterone levels (26.2 F 0.4 ng ml À 1) and plasma protein phosphorus (PPP, 1.33 F 0.3 mg ml À 1). The fish from the 6w 5m batch showed the highest plasma estradiol and testosterone levels, whereas the 3w 5m group showed the largest GSI. At the end of the experiment, several spontaneous out-of-season spawnings were collected in batch 6w 5m. Biopsy showed that most oocytes from groups 3w 5m and 6w 5m females were mature (migration of the germinal vesicle
Scientia Marina, 2007
The white-margined sole, Dagetichthys marginatus, was identified as a suitable candidate species for aquaculture in South Africa, based on life history strategy (fecundity, maturity, egg size, inter alia), good natural growth rates and an established, lucrative market for flatfish (Thompson, 2004). Wild broodstock were successfully induced to spawn and the larvae were SCIENTIA MARINA 71(3)
Canadian Journal of Fisheries and Aquatic Sciences, 1983
Spawning times for English sole (Parophrys vetulus) in Oregon waters were estimated for 13 yr using data on adult female gonadal condition, and surveys of pelagic larvae and benthic juveniles of known ages. The spawning season for this species is extremely protracted and variable. Some spawning may occur in all months, but most occurs between September and April, with a peak lasting 1–3 mo within this period. Variations in the English sole spawning season appear to be largely accountable by variations in a continental shelf temperature index (developed from a relationship with Neah Bay sea level). The following three hypotheses about temperature control of spawning were described by mathematical relationships which were incorporated into a simulation model that was driven by the time series of the bottom temperature index: (1) the rate of gonadal development is inversely related to summer bottom temperatures; (2) spawning is inhibited by temperatures below about 7.8 °C; and (3) spaw...