An atlas of the growth, mortality and recruitment of Philippine fishes

Growth, Mortality, Recruitment, Size distribution, Population dynamics, Fishery biology, Stock assessment, Length, Philippines, Teleostei

Female mating preferences in blind cave tetras Astyanax fasciatus (Characidae, Teleostei).

The Mexican tetra Astyanax fasciatus has evolved a variety of more or less color- and eyeless cave populations. Here we examined the evolution of the female preference for large male body size within different populations of this species, either surface- or cave-dwelling. Given the choice between visual cues from a large and a small male, females from the surface form as well as females from an eyed cave form showed a strong preference for large males. When only non-visual cues were presented in darkness, the surface females did not prefer either males. Among the six cave populations studied, females of the eyed cave form and females of one of the five eyeless cave populations showed a preference for large males. Apparently, not all cave populations of Astyanax have evolved non-visual mating preferences. We discuss the role of selection by benefits of non-visual mate choice for the evolution of non-visual mating preferences

Action of the Metalloproteinases in Gonadal Remodeling during Sex Reversal in the Sequential Hermaphroditism of the Teleostei Fish Synbranchus marmoratus (Synbranchiformes: Synbranchidae)

Teleostei present great plasticity regarding sex change. During sex reversal, the whole gonadincluding the germinal epithelium undergoes significant changes, remodeling, and neoformation.However, there is no information on the changes that occur within the interstitial compartment.Considering the lack of information, especially on the role played by metalloproteinases (MMPs)in fish gonadal remodeling, the aim of this study was to evaluate the action of MMPs on gonadsof sex reversed females of Synbranchus marmoratus, a fresh water protogynic diandric fish. Gonadswere processed for light microscopy and blood samples were used for the determination of plasmasex steroid levels. During sex reversal, degeneration of the ovaries occurred and were graduallyreplaced by the germinal tissue of the male. The action of the MMPs induces significant changesin the interstitial compartment, allowing the reorganization of germinal epithelium. Leydig cellsalso showed an important role in female to male reversion. The gonadal transition coincides withchanges in circulating sex steroid levels throughout sex reversion. The action of the MMPs, in thegonadal remodeling, especially on the basement membrane, is essential for the establishment of anew functional germinal epithelium.Fil: Mazzoni, Talita Sarah. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Lo Nostro, Fabiana Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Ecotoxicología Acuática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Antoneli, Fernanda. Universidade Estadual de Campinas; BrasilFil: Quagio-Grassiotto, Irani. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi

Apletodon gabonensis, a new species of clingfish (Teleostei: Gobiesocidae) from Gabon, eastern Atlantic Ocean

The clingfish Apletodon gabonensis sp. nov. is described on the basis of seven specimens and colour photographs from Gabon, eastern Atlantic Ocean. The species is small, apparently not exceeding 20 mm total length; it is characterized by having 5 dorsal-fin rays, 4-5 anal-fin rays, 25-27 pectoral-fin rays, head width in males 2.6-4.7 in SL, anus in males with urogenital papilla present but not pronounced; snout long, broad, anteriorly truncate in male, narrower and rather pointed in female; preorbital length 1.8-3.8 in head length; conspicuous maxillary barbel absent in both sexes; disc with 10-12 rows of papillae in region A, 5 rows of papillae in region B, and 5-7 rows of papillae in region C. The new species is compared with the other species of the genus; a key to the males of the 6 known species of the eastern Atlantic genus Apletodon is presented.info:eu-repo/semantics/publishedVersio

Hyphessobrycon nicolasi (Teleostei: Characidae) a new species from the Uruguay River basin in the Mesopotamian Region, Argentina

Hyphessobrycon nicolasi is described from the Uruguay River basin in the Mesopotamian Region, Entre Ríos, Argentina. The new species can be distinguished from all congeners by the presence of a well-defined oblique and marginal black stripe on each lobe of the caudal fin. Other characters defining H. nicolasi are the possession of 1-3 teeth with 3-10 cusps on maxilla; outer premaxillary row with 2-3 small teeth, with 5 or 7 cusps; iv-vi, 27-36 anal-fin rays; 33-36 scales on the longitudinal series; two vertical dark spots on the humeral region; dorsal and anal fins dappled in black and base of caudal fin bearing conspicuous black spot; and the presence of bony hooks on the rays of dorsal, anal and caudal fins of the mature males.Fil: Miquelarena, Amalia Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Lopez, Hugo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; Argentin

The Victoria Falls, a species boundary for the Zambezi Parrotfish, Cyphomyrus discorhynchus (Peters, 1852), and the resurrection of Cyphomyrus cubangoensis (Pellegrin, 1936) (Mormyridae: Teleostei)

Cyphomyrus discorhynchus occurs in the Zambezi River and in the linked systems of the Kwando and the Okavango. We collected specimens from both above and below the Victoria Falls and recorded Electric Organ Discharges. We found a marked degree of anatomical differentiation among the specimens from the Zambezi delta to the Victoria Falls that represents a subspecific, geographical cline, reflecting the great length (1400 km) and high ecological diversity of that river section (Lower and Middle Zambezi). We confirm that the populations above the Falls (i.e. Upper Zambezi, Kwando and Okavango) are differentiated from those below, possessing fewer dorsal fin rays (a median of 30–31 rather than 33–34). The waveforms of the electric organ discharge pulses have four phases and show geographic variation but were briefer for specimens from below the Falls. We resurrect Cyphomyrus cubangoensis (Pellegrin, 1936) for the Upper Zambezi/Kwando/Okavango system

Present distribution of the threatened killifish Aphanius fasciatus (Actinopterygii, Cyprinodontidae) in the Maltese Islands

A survey of the nine localities from which the threatened Killifish Aphanius fasciatus has been recorded in the Maltese Islands showed that large and thriving populations exist at Salina, at the Simar and Ghadira bird sanctuaries and in reservoirs at Marsa and Ghadira. The Simar and Ghadira populations are introduced and originate from a mixture of animals collected from Salina and Marsa. The provenance of the Marsa population is unknown but it is possibly autochthonous to the Marsa area. The Salina and possibly the Marsa populations seem to be the only remaining natural populations of this species in the Maltese Islands.peer-reviewe

Electric communication during courtship and spawning in two sibling species of dwarf stonebasher from southern Africa, Pollimyrus castelnaui and P. marianne (Mormyridae, Teleostei): evidence for a non species-specific communication code?

The fixed part of the electrocommunication signal, the electric organ discharge (EOD) waveform, is well differentiated in the two vicariant dwarf stonebasher species, Pollimyrus castelnaui and P. marianne. However, differentiation regarding the variable, situation-dependent part, i.e., inter-discharge interval (IDI) patterns, has never been studied in a pair of sibling species of mormyrid fish. We here compare the electrical signalling that accompanies different motor behaviours (such as resting and swimming, territorial agonistic interactions, courtship and spawning) in the two species. Double pulse patterns of regularly alternating short IDIs of 8-11 ms and long ones of 16-100 ms accompanied threat displays in both species. In three pairs of P. marianne and five pairs of P. castelnaui, courtship was characterised by nest building, territory patrolling and acoustic displays (advertisment calls) that were accompanied by long discharge breaks in the male and highly regular IDIs around 50 ms in the female of both species. Nest-tending males showed IDI sequences consisting of regularly alternating double pulse patterns, similar to threat displays. During spawning both sexes generated stereotyped IDI sequences of a low discharge rate. All IDI patterns occurring in one species were also found in the other, and no species-specifity was identified at that level. Playback experiments contrasting conspecific and heterospecific IDI sequences (that had been recorded from nocturnally swimming fish) revealed preferences in none of the six experimental subjects. Double pulse patterns, high discharge rate displays (HD) and regularisations of the IDI sequence accompanying specific behaviours occurred in similar form in both dwarf stonebasher species of the present study. Therefore, we conclude that in the speciation of P. castelnaui and P. marianne the fixed part of the EOD, its waveform, was under more differential selection pressure than its variable part, the patterns of IDI

Lecanogaster gorgoniphila, a new species of clingfish (Teleostei: Gobiesocidae) from São Tomé and Principe, eastern Atlantic Ocean

The clingfish Lecanogaster gorgoniphila new species, an unusual species associated with gorgonians, is described on the basis of 7 specimens and colour photographs from São Tomé Island, São Tomé and Principe, eastern Atlantic Ocean. The species is small, probably not exceeding 28 mm total length; it is characterized by having 4-5 dorsal-fin rays, 3-4 anal-fin rays, 21-23 pectoral-fin rays, and 11-14 principal caudal-fin rays; 12-14 rakers on third gill arch, very small, partially fused; papillae in centre of pelvic disk forming a round patch; pelvic disc region B with 5-6 rows of papillae; head relatively short, its length 2.4-3.4 in SL, and relatively narrow, its width 4.5-7.4 in SL; colouration of head and body variable in life, usually dorsally reddish white, ventrally rose, with eight bright red bars with scattered white spots. The new species is compared with other species of the eastern Atlantic genera Lecanogaster and Diplecogaster; a key to the species of the genus Lecanogaster Briggs, 1957 is presented.info:eu-repo/semantics/publishedVersio

Ontogeny of the osteocranium in the African catfish, Clarias gariepinus burchell (1822) (Siluriformes: Clariidae): Ossification sequence as a response to functional demands

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