Reproductive biology of three species of midwater fishes associated with the continental slope of eastern Tasmania, Australia

Comparative reproductive biology of three dominant myctophids of the genus Diaphus on the slope region of the East China Sea

“…In this study, there were more females than males in the catches of D. garmani and D. chrysorhynchus, and a similar pattern has been reported in many other myctophids in the world's oceans (Gjøsaeter, 1981;Clarke, 1983;Young et al, 1987;Prosch, 1991;Gartner, 1993;Sassa et al, 2014). This would contribute to the greater biomass of females than that of males and to maximize the egg-producing biomass (Clarke, 1983;Young et al, 1987).…”

“…Sex was examined for all specimens by macroscopic observation of the gonad morphology using a stereomicroscope. In all three species studied here, males have a markedly smaller gonad than females (see results), as reported for several other myctophids from subtropical-tropical to subarctic waters (Clarke, 1983;Young et al, 1987;Gartner, 1993;Moku, 2000;Sassa et al, 2014). Therefore, with the exception of sex ratio data, the following results were analyzed for females only.…”

“…In order to understand the mechanism of the high population productivity, studies on the reproductive biology of myctophids have been conducted in the world's oceans, including sex ratio, oocyte development, sizes at sexual maturity, spawning seasons, fecundity, and spawning strategies (e.g. Clarke, 1984;Lisovenko and Prut'ko 1987a;Young et al, 1987;Dalpadado, 1988;Prosch, 1991;Gartner, 1993;García-Seoane et al, 2014;Sassa et al, 2014).…”

Spring spawning and early nursery zone of the mesopelagic fish Maurolicus parvipinnis at the coastal upwelling zone off Talcahuano, central Chile

“…Interestingly, these 15 species show similarities in their habitats and reproductive strategies, as most spawn at the shelf break or continental slope in spring (October in the Southern Hemisphere) (Robertson 1976, Young et al 1987, Armstrong & Prosch 1991, Prosch 1991, Olivar et al 1992, John & Kloppmann 1993, Goodson et al 1995, Salvanes & Stockley 1996. Information on the spawning season of M. parvipinnis was not available until to date.…”

“…Most biological information exists on M. walvisensis, which used to be known as M. muelleri. These species spawn throughout the year, with peaks in late winter through spring (Young et al 1987, Armstrong & Prosch 1991, Prosch 1991. The spawning populations are confined to the continental slope in the vicinity of landmasses (Robertson 1976, Hulley & Prosch 1987.…”