Reef Fish Biology Research Papers (original) (raw)

We present a checklist of 278 species of reef fishes recorded along the coastline of Santa Catarina state, the southernmost limit of distribution of tropical ichthyofauna on the coast of Brazil. Twelve new species records for this state are presented: Acanthurus coeruleus, Acanthurus monroviae, Apogon americanus, Cantherhines macrocerus, Chaetodon sedentarius, Chromis flavicauda, Clepticus brasiliensis, Decapterus punctatus, Gymnothorax vicinus, Herpetoichthys regius, Muraena retifera and Stegastes partitus. Stegastes partitus and H. regius are reported for the first time, respectively, from the Southwestern Atlantic and for the coastal part of this region, while Acanthurus monroviae is reported for the second time for the Southwestern Atlantic. We present habitat distribution, trophic structure and comment on biogeographic affinities of this transitional region, discussing both remarkable species presences and absences.

- by and +2
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- Reef Fish Biology, Reef Fish Ecology

Three species of seahorses of the genus Hippocampus are recognized within the Hawaiian Islands, H. kuda, H. fisheri and H. histrix. Based on molecular and morphological evidence H. kuda is treated here as two subspecies, the Hawaiian H. kuda hilonis and H. kuda kuda from elsewhere in the Indo-Pacific region. Molecular analysis also indicates that recent populations of H. kuda hilonis are not based on introduced fishes as their cytb sequence is identical to that of the H. hilonis holotype. Hippocampus fisheri is endemic to the Hawaiian Islands. The Hawaiian record of H. histrix is based on a specimen collected from O‘ahu in 1877 and one reported from Maui in 1928. The specimens are identified correctly, and there is no reason to doubt these old records, illogical as they seem.

- by Rob Toonen
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- Taxonomy, Reef Fish Biology, Coral Reef Fishes, Seahorses

Sagittae otoliths are the most studied because of their morphological variability and size; the sagittae may also have valuable taxonomic use and for D. auratus has not yet been described. In the present study we present a morphological description of the sagitta otolith and an analysis of its correlation with various morphometric parameters. The biological material was captured with a beach seine in the coasts of Alvarado and Port of Veracruz, from November 2009 to June 2010. Sagittae were extracted, cleaned, photographed (SEM and optical), and measured. The analysis included the correlations between sagitta's length and width, versus the fish standard length, height and weight, for a total of 449 fishes. The comparison between left and right sagitta showed no significant difference in both otolith length and width (t-tests, p<0.05) for each sex. The right otolith was used for the correlations for both males and females and the Fisher test (d.f. 161 and 143, p<0.001) showed no significant differences in the slopes and intersections between them. The otolith length vs. fish weight correlation showed a positive allometric growth in males (b=3.9754, p<0.05) and females (b=4.3168, p<0.05). Rev. Biol. Trop. 61 (1): 139-147. Epub 2013 March 01.

- by Veronica Rivera
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- Marine Biology, Reef Fish Biology, Ictiology

This work examined 64 large, carnivorous reef fish from the coastal waters of Cameroon for toxicity commonly associated with an incidence of ciguatera fish poisoning. The samples were also subjected to m-DNA analyses to confirm their taxonomic identification. The analyses showed that a subgroup of fish locally referred to as groupers are actually in the snapper family (Lutjanus spp.). Extracts from 22 barracuda Sphyraena barracuda and 42 snapper Lutjanus spp. samples were prepared and examined for the presence of ciguatera-like toxins. Sodium-channel activation was assessed by a sodiumchannel-specific bioassay using mouse neuroblastoma (N2a) cells. Extracts were also subjected to chemical analysis via liquid chromatography/mass spectrometry (LC/MS) to compare the mass of peaks of interest to the molecular weights of fish toxins previously described. Two barracuda and one snapper tested positive for a sodium-channel activator, i.e. presumptive ciguatoxin, in the N2a assay. LC/MS analyses showed that only these three samples contained high-intensity peaks, with masses of 1 222 amu and 1 279 amu. These results represent the first analytical report indicating the presence of sodium-channel-specific neurotoxins in fish from along the coast of West Africa. Given the importance of such marine carnivores to the nutrition and socio-economy of the coastal populace, education and disease management appear to be warranted.

- by Rob Toonen
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- Reef Fish Biology, Ciguatera, Ciguatoxins, ToBo Lab

Seagrass beds and mangroves are distributed in tropical regions all over the world and considered important nurseries for coral reef fish species. Studies in the Caribbean have shown that seagrass beds and mangroves are the most important nurseries for juvenile coral reef fish, and when juveniles become adults they move to the coral reefs. Coral reef fish in the Indo-Pacific region do not show such a consistent pattern. In this region it is not clear to what extent coral reef fish use available habitats in a non-reef – coral reef gradient and what the influence is of the presence of non-reef habitats as a nursery on coral reef fish populations on coral reefs. The present study was carried out on four islands along the coast of Tanzania and on one island in the Comoros archipelago in the western Indian Ocean. Using a point count visual census method during the day, the length, abundance and distribution of 76 commercially important coral reef fish species were studied. In total, 2279 quadrats were surveyed at six different non-reef habitats, on coral reefs adjacent to seagrass beds and mangroves (reef sg-mg), on coral reefs at a greater distance to seagrass beds and mangroves (reef far) and on coral reefs in the Comoros archipelago completely lacking seagrass beds and mangroves (reef Comoros). Results showed that shallow seagrass beds did harbour much higher juvenile fish densities than mangroves, deep seagrass beds, intertidal flats, algal beds and coral reefs. This suggests that shallow seagrass beds are the most important nurseries for juvenile coral reef fish. Furthermore, all 76 observed species were categorised in six species groups: sg residents, sg-reef transients, generalists, reef generalists, reef residents and rare species, based on their juvenile and adult distribution patterns between non-reef and reef habitats. Two species groups, sg-reef transients and reef generalists, showed possible migrations between non-reef and reef habitats, but only sg-reef transients, consisted of two species, showed a possible ontogenetic migration from seagrass beds towards the coral reef adjacent to non-reef habitats. This suggests that the nursery hypothesis affected only two species and all other species can use alternative habitats. On reef Comoros the six species groups were also present, but the number of species found on reef Comoros was much lower than on reef far. On reef far three species groups and on reef Comoros four species groups showed significant higher adult densities on reef sg-mg than on reef far or reef Comoros. This suggests that on the scale of an entire island, non-reef habitats have an impact on species groups. The presence of non-reef habitats influences coral reef fish densities on reef sg-mg. At species level, 22 species of the 50 observed species on reef far and 5 species of the 19 observed species on reef Comoros showed significantly higher adult densities on reef sg-mg than on reef far or reef Comoros. This indicates that these species have an advantage of nearby non-reef habitats as a juvenile habitat, but they can sustain on reef far or reef Comoros. On reef far 28 species and on reef Comoros 14 species showed no effect of the absence of non-reef habitats on adult fish densities on the coral reef. It is suggested that these species are able to use the coral reef as an alternative nursery and do not depend on non-reef habitats. They can possibly spend their entire life cycle on the reef and are to some extent self-sustaining.

- by Monique Grol
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- Coral Reef Ecosystems, Mangroves, Reef Fish Biology, Fish Habitat Associations

Determining the life history consequences for fishes living in extreme and variable environments will be vital in predicting the likely impacts of ongoing climate change on reef fish demography. Here, we compare size-at-age and maximum body size of two common reef fish species (Lutjanus ehrenbergii and Pomacanthus maculosus) between the environmentally extreme Arabian/Persian Gulf (‘Arabian Gulf’) and adjacent comparably benign Oman Sea. Additionally, we use otolith increment width profiles to investigate the influence of temperature, salinity and productivity on the individual growth rates. Individuals of both species showed smaller size-at-age and lower maximum size in the Arabian Gulf compared to conspecifics in the less extreme and less variable environment of the Oman Sea, suggesting a life-history trade-off between size and metabolic demands. Salinity was the best environmental predictor of interannual growth across species and regions, with low growth corresponding to more sa...

- by Geórgenes Cavalcante
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- Earth Sciences, Coral Reefs, Fish Biology, Reef Fish Biology

Determining the life-history consequences for fishes living in extreme and variable environments will be vital in predicting the likely impacts of ongoing climate change on reef fish demography. Here, we compare size-at-age and maximum body size of two common reef fish species (Lutjanus ehrenbergii and Pomacanthus maculo-sus) between the environmentally extreme Arabian/Persian Gulf ('Arabian Gulf') and adjacent comparably benign Oman Sea. Additionally, we use otolith increment width profiles to investigate the influence of temperature, salinity and productivity on the individual growth rates. Individuals of both species showed smaller size-at-age and lower maximum size in the Arabian Gulf compared to con-specifics in the less extreme and less variable environment of the Oman Sea, suggesting a life-history trade-off between size and metabolic demands. Salinity was the best environmental predictor of interannual growth across species and regions, with low growth corresponding to more saline conditions. However, salinity had a weaker negative effect on interannual growth of fishes in the Arabian Gulf than in the Oman Sea, indicating Arabian Gulf populations may be better able to acclimate to changing environmental conditions. Temperature had a weak positive effect on the interannual growth of fishes in the Arabian Gulf, suggesting that these populations may still be living within their thermal windows. Our results highlight the potential importance of osmoregulatory cost in impacting growth, and the need to consider the effect of multiple stressors when investigating the consequences of future climate change on fish demography.

- by John A Burt and +1
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- Coral Reefs, Fish Biology, Reef Fish Biology, Arabian Gulf

The length frequencies and age structures of resident Pseudanthias rubrizonatus (n = 407), a small protogynous serranid, were measured at four isolated artificial structures on the continental shelf of north-western Australia between June and August 2008, to determine whether these structures supported full (complete size and age-structured) populations of this species. The artificial structures were located in depths between 82 and 135 m, and growth rates of juveniles and adults, and body condition of adults, were compared among structures to determine the effect of depth on potential production. All life-history stages, including recently settled juveniles, females and terminal males, of P . rubrizonatus were caught, ranging in standard length (L s ) from 16·9 to 96·5 mm. Presumed ages estimated from whole and sectioned otoliths ranged between 22 days and 5 years, and parameter ± s.e. estimates of the von Bertalanffy growth model were L ∞ = 152 ± 34 mm, k = 0·15 (±0·05) and t 0 = −1·15 (±0·15). Estimated annual growth rates were similar between shallow and deep artificial structures; however, otolith lengths and recent growth of juveniles differed among individual structures, irrespective of depth. The artificial structures therefore sustained full populations of P . rubrizonatus, from recently settled juveniles through to adults; however, confirmation of the maximum age attainable for the species is required from natural populations. Depth placement of artificial reefs may not affect the production of fish species with naturally wide depth ranges.

- by Ashley Fowler
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- Fish Biology, Reef Fish Biology, Artificial Reefs

Bluespine unicornfish (Naso unicornis) from Hawaii were aged to >50 years using cross-sectioned sagittal otoliths. Fish length was a poor indicator of age because of rapid and variable early growth, exemplified by fish aged to be 4 years near maximum length. Growth was deterministic with adult ages decoupled from body length. Otolith mass and thickness were evaluated as proxies for age and both were encouraging; thickness explained more variance but mass was easier to measure. An age estimation protocol was validated through ontogeny using bomb radiocarbon (14 C) dating. Use of the postbomb 14 C decline period from a regional reference chronology enabled age validation of young fish — a novel approach for the Pacific Ocean. A probabilistic procedure for assigning bomb 14 C dates (CALIBomb) was used for the first time to determine fish birth years. The age-reading protocol was generally validated, and it was possible to describe length-at-age despite difficulties in counting otolith annuli beyond 30–40 years. Growth curves differed between the sexes, and a four-parameter generalized von Bertalanffy growth function provided the best fit.

- by Allen H Andrews and +1
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- Marine Ecology, Fisheries Science, Fisheries, Coral Reef Ecosystems

Uncontrolled recreational activities are known to cause severe damage to reef dwelling organisms and to the reef overall structure. In order to investigate the effects of human recreational activities on the reef fish assemblage, surveys were undertaken in two shallow coastal reefs (Picãozinho and Quebra Quilhas) with similar physiographic features. However, recreational activities only take place at the former, and the latter was investigated as a control reef. The most speciose and abundant families on both reefs were Pomacentridae, Scaridae, Haemulidae, Acanthuridae and Labridae, but species evenness was fairly different between the reefs due in particular to the extremely high abundance of the sergeant major Abudefduf saxatilis at Picãozinho. This species represented almost ⅔ of all individuals recorded at Picãozinho and was the underlying feature responsible for the assemblage structure pattern observed on this reef. The present study showed that one single species was of major influence on species evenness and trophic structure, and that unregulated recreational activities have the potential to severely alter reef fish assemblage structure.

- by Cláudio Sampaio
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- Ichthyology, Conservation Biology, Marine Ecology, Marine Protected Areas

- by Veronica Rivera
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- Marine Biology, Reef Fish Biology, Morphometry, Mexico

The present study was conducted on Tamandaré reefs, northeast Brazil and aimed to analyse the importance of different factors (e.g. tourism activity, fishing activity, coral abundance and algal abundance) on reef fish abundance and species richness. Two distinct reef areas (A ver o mar and Caieiras) with different levels of influence were studied. A total of 8239 reef fish individuals were registered, including 59 species. Site 1 (A ver o mar) presented higher reef fish abundance and richness, with dominance of roving herbivores (29.9 %) and mobile invertebrate feeders (28.7 %). In contrast, at Site 2 (Caieiras) territorial herbivores (40.9 %) predominated, followed by mobile invertebrate feeders (24.6 %). Concerning the benthic community, at Site 1 macroalgae were recorded as the main category (49.3 %); however, Site 2 was dominated by calcareous algae (36.0 %). The most important variable explaining more than 90 % of variance on reef fish abundance and species richness was macroalgae abundance, followed by fishing activity. Phase shifts on coral reefs are evident, resulting in the replacement of coral by macroalgae and greatly influencing reef fish communities. In this context, it is important to understand the burden of the factors that affect reef fish communities and, therefore, influence the extinction vulnerability of coral reef fishes.

- by Daniel Lino Lippi
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- Fisheries, Reef Fish Biology, Coral Reef Fishes, Vagrant Tropical Reef Fishes

- by Allan Souza and +2
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- Ichthyology, Conservation Biology, Brazil, Fish Biology