Thesis (Ph. D.)--University of California, Los Angeles-Zoology. / Typewritten.

Thesis (Ph. D.)--College of William and Mary. / Vita. Includes bibliographical references. Also available via the World Wide Web.

Not available / text

Thesis (Ph.D.)--Murdoch University, 2008. / Thesis submitted to the Faculty of Sustainability, Environmental and Life Sciences. Includes bibliographical references (leaves 182-217)

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisor: Peter Thomas. Vita. Includes bibliographical references.

A study of the biology, anatomy and taxonomy of the sciaenid fishes of the genus Argyrosomus from South Africa and Namibia revealed that three species were confused under the name "Argyrosomus Izololepidotus (Lacepède 1801)". Comparison of morphometric and meristic data, otoliths, swim-bladders, drumming muscles, and other morphological features of specimens from southern Africa, Madagascar, the Mediterranean, the eastern Atlantic Ocean, Japan and Australia, revealed that "A. hololepidotus" is a complex of four species: A. japonicus (Temminck & Schlegel 1843), which occurs off southern Africa, Japan and Australia; A. inodorus sp. nov., which is known from Namibia to the Kei River (32°40'S) on the east coast of South Africa; A. coronus sp. nov., which is known from central and northern Namibia and Angola, and A. hololepidotus, which appears to be endemic to Madagascar. Both A. japonicus and A. inodorus are important recreational and commercial linefish species in South Africa. Although A. inodorus occurs on the east and west coasts of South Africa, and A. japonicus is found between Cape Point and Mozambique, the former species is abundant only between Cape Point and the Kei River, and the latter species from Cape Agulhas to northern KwaZulu/Natal. The life-histories of Argyrosomus japonicus and A. inodorus, within these respective ranges, were elucidated using length-at-age, reproductive, catch and effort, size composition, otolith dimension/fish length and tagging data. Median sizes at maturity (L₅₀) for A. japonicus were 920 mm TL (5 years) for males and 1070 mm TL (6 years) for females. All males >1100 mm TL (7 years) and all females >1200 mm TL (8 years) were mature. Females grew faster than males, but in both sexes growth slowed dramatically after maturity. Maximum age recorded was 42 years, but fish older than 27 years were rare. Adult A. japonicus were predominantly found in the nearshore marine environment, but also occurred in estuaries and in the surf zone. Spawning takes place in the nearshore environment, from August to November in Natal, and from October to January in the Southern and South-Eastern Cape regions. A large proportion of the adult population migrate to Natal to spawn, although spawning may continue once they return to the Cape. Early juveniles of 20-30 mm TL recruit into turbid estuaries along the entire east coast, possibly aided by olfactory cues. They appear to remain in the upper reaches of the estuaries where they find suitable food and refuge from predators until they grow to about 150 mm TL. Juveniles larger than this size were found in the middle and lower reaches of estuaries and also in the surf zone. Juvenile A. japonicus (<1000 mm TL) generally did not migrate long distances, but remained as separate sub-stocks until they reached maturity. A. inodorus grows more slowly than A. japonicus, and attains a lower maximum age (25 years) and a smaller maximum size (34 vs 75 kg). There was no significant difference between the growth rates of male and female A. inodorus. Those in the South-Westem Cape initially grew faster than those on the east coast, but growth slowed sooner in the former region with the result that these fish attained a smaller maximum size. Although ripe A. inodorus were sampled throughout the year, there was a distinct spawning season from August to December, with a peak in spring (Sept-Nov). Spawning occurred throughout the study area for this species, in <50 m depth. Size at sexual maturity for A. inodorus was smaller in the South-Eastern Cape than in the Southern Cape. Median size at maturity for females was attained at 310 mm TL (1.3 years) in the former and at 375 mm TL (2.4 years) in the latter region, and the length at which all females were mature was 400 mm (3.5 years) and 550 mm (4.7 years) respectively. For males the estimates of Lso and total maturity were 200 mm (1 year) and 400 mm (2.8 years) for the SouthEastern Cape and 250 mm (1.5 years) and 450 mm (3.4 years) in the Southern Cape. East of Cape Agulhas, A. inodorus was found from just beyond the surf zone to depths of 120 m. Adults occurred predominantly on reef (>20 m) while juveniles were found mainly over soft substrata of sand/mud (5-120 m depth). Early juveniles do not enter estuaries, but apparently recruit to nursery areas immediately beyond the backline of breakers (5-10 m depth), and then move seawards with growth. No juveniles were obtained from the area west of Cape Agulhas as substrates <200 m depth were unsuitable for trawling. Due to lower water temperatures, the adults in this area were found from within the surf zone to depths of only 20 m. East and west of Cape Agulhas there was evidence of offshore dispersal in winter, in response to oceanographic changes. Based upon otolith morphology, juvenile and adult distribution patterns, sizes at sexual maturity and on tagging data, A. inodorus between Cape Point and the Kei River apparently exist as three separate stocks, one in the South-Eastern Cape, one in the Southern Cape and one in the South-Western Cape, with limited exchange. The life-histories of A. japonicus and A. inodorus are discussed in terms of their management. The large size at maturity of A. japonicus together with evidence for considerable human impact on the early juvenile, juvenile, and the adult phases of the life-cycle indicate that estuarine nursery habitats need to be conserved, that the minimum size limit should be increased, and that current bag limits for this species should be reviewed. Although the current minimum size limit provides protection for A. illodorus until maturity, evidence is presented which indicates that at least one and possibly all of the stocks of this species are currently over-exploited. Stock assessment of the South African A. japonicus and A. inodorus resources, and the implementation of effective management strategies, are therefore a matter of urgency.

No description available.

No sudeste e sul do Brasil, os peixes da família Sciaenidae estão entre os peixes mais pescados sobre a plataforma continental interna. O conhecimento da ocorrência tanto espacial quanto temporal dos indivíduos na fase de transformação, que se estabelecem no local onde se desenvolverão, torna-se informação fundamental para o entendimento do ciclo de vida das espécies e, por extensão, para ações de preservação e de manejo de recurso. Porém, descrições das espécies de Sciaenidae na fase de transformação são escassas, impedindo a identificação desses peixes. Neste trabalho são estudadas 22 espécies das 28 de Sciaenidae do sudeste e sul do Brasil no estágio de desenvolvimento de transformação com base em material acumulado nas instituições que mantém coleções de peixe. Séries de crescimento de 16 dessas espécies foram morfologicamente descritas e ilustradas, bem como elaborada uma chave de identificação das espécies que ocorrem na área. A ocorrência espacial e temporal das amostras foram mapeadas, sendo estimada a época de nascimento e confrontada com a literatura sobre crescimento e reprodução. Foi observado que a maioria das espécies se restringe a estuários e baías, em águas rasas, havendo indícios de predomínio da época de nascimento (e portanto, de desova) no verão. / In the southeast and south of Brazil, the Sciaenidae are among the most caught fishes on the shallow waters of the continental shelf. Spacial and temporal occurrence knowledge of individuals at the transformation stage is a fundamental information for understanding the life cycle of the species and, by extension, for preservation and management action. Morphological descriptions of Sciaenidae fishes at that developmental stage are scarce, preventing their taxonomic identification. In this work 22 species from the 28 of Sciaenidae in the southeast and south of Brazil are studied on the transformation stage based on material from the institutions that maintain collections of fish. Series of growth of 16 of these species were morphologically described and illustrated, as well as draft a key to identify the species that occur in the area. The spacial and temporal distribution of the samples were mapped, being estimated the time of birth and faced with the literature on growth and reproduction. It was observed that most species are strict to shallow waters of estuaries and bays, with evidence of the predominance of the time of birth (and therefore spawning) in the summer.

No sudeste e sul do Brasil, os peixes da família Sciaenidae estão entre os peixes mais pescados sobre a plataforma continental interna. O conhecimento da ocorrência tanto espacial quanto temporal dos indivíduos na fase de transformação, que se estabelecem no local onde se desenvolverão, torna-se informação fundamental para o entendimento do ciclo de vida das espécies e, por extensão, para ações de preservação e de manejo de recurso. Porém, descrições das espécies de Sciaenidae na fase de transformação são escassas, impedindo a identificação desses peixes. Neste trabalho são estudadas 22 espécies das 28 de Sciaenidae do sudeste e sul do Brasil no estágio de desenvolvimento de transformação com base em material acumulado nas instituições que mantém coleções de peixe. Séries de crescimento de 16 dessas espécies foram morfologicamente descritas e ilustradas, bem como elaborada uma chave de identificação das espécies que ocorrem na área. A ocorrência espacial e temporal das amostras foram mapeadas, sendo estimada a época de nascimento e confrontada com a literatura sobre crescimento e reprodução. Foi observado que a maioria das espécies se restringe a estuários e baías, em águas rasas, havendo indícios de predomínio da época de nascimento (e portanto, de desova) no verão. / In the southeast and south of Brazil, the Sciaenidae are among the most caught fishes on the shallow waters of the continental shelf. Spacial and temporal occurrence knowledge of individuals at the transformation stage is a fundamental information for understanding the life cycle of the species and, by extension, for preservation and management action. Morphological descriptions of Sciaenidae fishes at that developmental stage are scarce, preventing their taxonomic identification. In this work 22 species from the 28 of Sciaenidae in the southeast and south of Brazil are studied on the transformation stage based on material from the institutions that maintain collections of fish. Series of growth of 16 of these species were morphologically described and illustrated, as well as draft a key to identify the species that occur in the area. The spacial and temporal distribution of the samples were mapped, being estimated the time of birth and faced with the literature on growth and reproduction. It was observed that most species are strict to shallow waters of estuaries and bays, with evidence of the predominance of the time of birth (and therefore spawning) in the summer.

The fishes of the family Sciaenidae have been known to vocalize during the reproductive season, and it is known that in most species only the male calls. Sounds are produced by vibration of the sonic muscles, which set the swim bladder into resonance. In addition, they also emit sounds by the same mechanism while being disturbed. The large yellow croaker, Larimichthys crocea (Perciformes, Sciaenidae) is one of the important commercial fish species distributed in South China Sea, East China Sea and southern Yellow Sea. In the past years, they have been overfished because of their high fishery value. Many aquatic farms started to culture economically important sciaenids because of the established artificial propagation technique. Now large yellow croakers have been successfully cultured in Fuchien Province, China. Unlike most sciaenids, the sonic muscles are only possessed by male, both male and female large yellow croakers have sonic muscles. This species provides the best opportunity to investigate the characteristics of sounds produced by different genders. The aims of this study were 1) to describe the hand-held disturbance sounds in large yellow croakers, 2) to describe the sounds produced during courtship and spawning in large yellow croakers being injected hormone (LHRH-A3), 3) to investigate the phylogenetic position of large yellow croaker in relation to other sciaenid fishes, and 4) to understand the evolutionary path of swim bladder morphology in the family Sciaenidae. The results show that 1) the pulse numbers of hand-held disturbance sounds in large yellow croaker can reach 23; 2) The reproductive sounds consisted of 1 to 7 pulses which started at about 1400 hr, and both vocal activity (no. sounds/min) and pulse numbers per call would increase with time. However, spawning occupied at the time slot when pulse numbers per call reached 7 in the unisex pond. The sounds in the ponds with only males or females can only recorded the sounds with 1 to 2 pulses; 3) The genus Collichthys was the sister taxon of large yellow croaker. Morphology of the swim bladder in Collichthys is similar to large yellow croaker; 4) Morphology of swim bladder evolved from simple to complex forms. Finally, Larimichthys, Collichthys, and other sciaenid genera distributed in the Indo-western Pacific Ocean including Miichthys, Boesemania, Bahaba, Panna, Atrobucca, Otolithes, Pterotolithus, Chrysochir, Paranebris, Protonibea, Pennahia, Nibea, Dendrophysa and Johnius form a monophyletic group with a bootstrap value of 100. Most of the members have the complex swim bladders with many appendages except Boesemania, Bahaba and Paranebris. Presence of simple form of the swim bladder in these three genera is inferred as a result of morphological reversal.