76 research outputs found
Eggs and larvae of the santer cheimerius nufar (Perciformes: Sparidae) from Kwazulu-Natal, South Africa
The santer Cheimerius nufar is a common reef fish on the east coast of South Africa and a popular target for offshore anglers. The eggs and larvae are described from specimens reared in the laboratory, from aquariumspawnedeggs and eggs collected at sea. Comparisons with eggs and larvae of other local sparids are made and data are presented on the seasonal occurrence of santer eggs in plankton samples
Morphological and genetic analyses of the first record of the Niger Hind, Cephalopholis nigri (Perciformes: Serranidae), in the Mediterranean Sea and of the African Hind, Cephalopholis taeniops, in Malta
Observations of spawning in the Leather Bass, Dermatolepis dermatolepis (Teleostei: Epinephelidae), at Cocos Island, Costa Rica
Total-Hg and organic-Hg in Cephalopholis fulva (Linnaeus, 1758) from inshore and offshore waters of NE Brazil
The population biology of the living coelacanth studied over 21 years
Between 1986 and 2009 nine submersible and
remote-operated vehicle expeditions were carried out to
study the population biology of the coelacanth Latimeria
chalumnae in the Comoro Islands, located in the western
Indian Ocean. Latimeria live in large overlapping home
ranges that can be occupied for as long as 21 years. Most
individuals are confined to relatively small home ranges,
resting in the same caves during the day. One hundred and
forty five coelacanths are individually known, and we
estimate the total population size of Grande Comore as
approximately 300–400 adult individuals. The local population
inhabiting a census area along an 8-km section of
coastline remained stable for at least 18 years. Using
LASER-assisted observations, we recorded length frequencies
between 100 and 200 cm total length and did not
encounter smaller-bodied individuals (\100 cm total
length). It appears that coelacanth recruitment in the
observation areas occur mainly by immigrating adults. We
estimate that the mean numbers of deaths and newcomers
are 3–4 individuals per year, suggesting that longevity may
exceed 100 years. The domestic fishery represents a threat
to the long-term survival of coelacanths in the study area.
Recent changes in the local fishery include a decrease in
the abundance of the un-motorized canoes associated with
exploitation of coelacanths and an increase in motorized
canoes. Exploitation rates have fallen in recent years, and
by 2000, had fallen to lowest ever reported. Finally, future
fishery developments are discussed
Fishery-Independent Data Reveal Negative Effect of Human Population Density on Caribbean Predatory Fish Communities
BACKGROUND: Understanding the current status of predatory fish communities, and the effects fishing has on them, is vitally important information for management. However, data are often insufficient at region-wide scales to assess the effects of extraction in coral reef ecosystems of developing nations. METHODOLOGY/PRINCIPAL FINDINGS: Here, I overcome this difficulty by using a publicly accessible, fisheries-independent database to provide a broad scale, comprehensive analysis of human impacts on predatory reef fish communities across the greater Caribbean region. Specifically, this study analyzed presence and diversity of predatory reef fishes over a gradient of human population density. Across the region, as human population density increases, presence of large-bodied fishes declines, and fish communities become dominated by a few smaller-bodied species. CONCLUSIONS/SIGNIFICANCE: Complete disappearance of several large-bodied fishes indicates ecological and local extinctions have occurred in some densely populated areas. These findings fill a fundamentally important gap in our knowledge of the ecosystem effects of artisanal fisheries in developing nations, and provide support for multiple approaches to data collection where they are commonly unavailable
Additional Records of Tripletail Lobotes surinamensis (Bloch, 1790), from the Eastern Mediterranean
Single-male paternity in coelacanths
Latimeria chalumnae, a ‘living fossil,’ is of great scientific interest, as it is closely related to the aquatic ancestors of land-living tetrapods. Latimeria show internal fertilization and bear live young, but their reproductive behaviour is poorly known. Here we present for the first time a paternity analysis of the only available material from gravid females and their offspring. We genotype two L. chalumnae females and their unborn brood for 14 microsatellite loci. We find that the embryos are closely related to each other and never show more than three different alleles per locus, providing evidence for a single father siring all of the offspring. We reconstruct the father’s genotype but cannot identify it in the population. These data suggest that coelacanths have a monogamous mating system and that individual relatedness is not important for mate choice
Feeding ecology of two sympatric species of large-sized groupers (Perciformes: Epinephelidae) on Southwestern Atlantic coralline reefs
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