The genus Pogonophryne is the most species-rich genus of barbeled plunderfishes(Artedidraconidae) and includes more than 25 poorly known species endemic to the Southern Ocean.In this study, we provide new data on the age and reproductive traits of some species of Pogonophrynefrom the southern Weddell Sea, inferred through otolith reading and histological analyses of gonads.Individual age estimates ranged between 16 and 18 years for Pogonophryne barsukovi andPogonophryne immaculata and between 10 and 22 years for Pogonophryne scotti. As is commonlyfound in notothenioids, P. barsukovi followed a group-synchronous type of ovarian development, withpre-vitellogenic and vitellogenic oocytes forming two well-separated egg-size groups. A singlespawning female in the sample produced ~1097 eggs and 7.9 eggs g-1. The sample of P. immaculataconsisted exclusively of developing males, with testes composed of cysts of spermatogonia,spermatocytes and spermatids. Pogonophryne scotti was the most abundant species, includingrelatively small males at immature or developing stages of gonad development. Larger females wereregressing, being characterized by ovaries with postovulatory follicles and atretic oocytes. Based onthe macroscopic and histological analyses of gonads, the spawning season would take place inautumn for P. barsukovi and P. immaculata and in spring-early summer for P. scotti.
Reproductive traits and age estimate of barbeled plunderfishes (Pogonophryne) from the Weddell Sea
Mario La Mesa
;Fortunata Donato;
2020
Abstract
The genus Pogonophryne is the most species-rich genus of barbeled plunderfishes(Artedidraconidae) and includes more than 25 poorly known species endemic to the Southern Ocean.In this study, we provide new data on the age and reproductive traits of some species of Pogonophrynefrom the southern Weddell Sea, inferred through otolith reading and histological analyses of gonads.Individual age estimates ranged between 16 and 18 years for Pogonophryne barsukovi andPogonophryne immaculata and between 10 and 22 years for Pogonophryne scotti. As is commonlyfound in notothenioids, P. barsukovi followed a group-synchronous type of ovarian development, withpre-vitellogenic and vitellogenic oocytes forming two well-separated egg-size groups. A singlespawning female in the sample produced ~1097 eggs and 7.9 eggs g-1. The sample of P. immaculataconsisted exclusively of developing males, with testes composed of cysts of spermatogonia,spermatocytes and spermatids. Pogonophryne scotti was the most abundant species, includingrelatively small males at immature or developing stages of gonad development. Larger females wereregressing, being characterized by ovaries with postovulatory follicles and atretic oocytes. Based onthe macroscopic and histological analyses of gonads, the spawning season would take place inautumn for P. barsukovi and P. immaculata and in spring-early summer for P. scotti.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
