Integrative study of the reproductive biology and growth of the characin dientudo paraguayo Acestrorhynchus pantaneiro (Characiformes, Acestrorhynchidae) presented as a protandrous hermaphroditic fish.

PIAZZA YANINA GRISEL; LOZANO ISMAEL ; LLAMAZARES VEGH SABINA; LO NOSTRO FABIANA; FUENTES CARLOS MARIANO

JOURNAL OF FISH BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2023

0022-1112

In this contribution, we studied the reproductive strategy, sexual system and growth of dientudo paraguayo Acestrorhynchus pantaneiro. After two years of monitoring in shallow areas of a floodplain lake from the lower Paraná basin (Argentina), it was evidenced that water temperature modulated gonadal maturation, but it was river water level the synchronizing stimulus that triggered spawning. This species exhibited a single annual breeding period from October to January, with most spawning activity in November. According to the von Bertalanffy growth curve, fish would reach autumn to winter months with approximately 120 mm LS, already being mature males. The first mature females were found at 210 mm LS being sexually mature between the second and third breeding seasons. This is the first integrative study that includes the body-length frequency distribution, sex differential size at first maturity and growth; and reports the presence of intersex gonads questioning its status from gonochoristic to sequential hermaphrodite species. The sexual pattern, the multiple spawning behavior, and a medium to high absolute fecundity support the opportunistic description that goes along with the invasive behavior observed in previous contributions for this characiform species.