Integrative study of the reproductive biology and growth of Acestrorhynchus pantaneiro Menezes, 1992 (Characiformes, Acestrorhynchidae)

PIAZZA, YANINA G.; LOZANO, ISMAEL E.; VEGH, SABINA LLAMAZARES; LO NOSTRO, FABIANA L.; FUENTES, CARLOS M.

JOURNAL OF FISH BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2023

0022-1112

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