Vol. 60, 2021

(update: 2021.01.08; 02.24)
 

Synchrony between Reproductive Phase and Flood Period: A Dispersion Mechanism for the Freshwater Clam Corbicula fluminea (Bivalvia: Corbiculidae) in a Brazilian Neotropical Floodplain

Claudenice Dei Tos^1,*, Camila Antoniassi Cardim², Vanessa de Brito Pereira², and Roger Paulo Mormul¹

¹Departamento de Biologia, Núcleo de Pesquisas em Limnologia, Ictiologia e Aquicultura (Nupélia), Universidade Estadual de Maring? Av. Colombo 5790, Bloco H90, Jd. Universitário, Maring? PR CEP 87020-900, Brazil. *Correspondence: E-mail: claudenice@nupelia.uem.br (Tos)
E-mail: roger@nupelia.uem.br (Mormul)
²Curso de graduação em Ciências Biológicas, Departamento de Biologia, Universidade Estadual de Maringá. Av. Colombo 5790, Bloco G90, Jd. Universitário, Maringá, PR CEP 87020-900, Brazil. E-mail: camilacardin.bio@gmail.com (Cardim); vanessa_zimer@hotmail.com (Pereira)

Received 14 October 2020 / Accepted 31 December 2020
Communicated by Benny K.K. Chan

This study evaluates the gonadal histology of Corbicula fluminea present in the upper Paran?River floodplain and samples of limnological variables to understand its reproductive cycle. Corbicula fluminea was monitored monthly from December 2013 to February 2015. Spermatogonia, primary and secondary spermatocytes, spermatids and spermatozoa were identified in the male follicles of the hermaphrodites. Oogonia, oogonial nests, previtellogenic oocytes, early vitellogenic oocytes, middle vitellogenic oocytes and full-grown vitellogenic oocytes were identified in the female follicles of the hermaphrodites and females. The reproductive phases were described as developing, active spawning/sperm releasing, regression and recovery. Higher values of temperature, dissolved oxygen, total nitrogen and total phosphorous were identified during flood periods, while higher values of pH and conductivity were obtained during dry periods. The species either does not reproduce or reduces the intensity of reproduction in cold months, with the sex ratio not differing significantly between hermaphrodites and females with regard to month and reproductive phase. Thus, reproduction is synchronized with the flood period and its limnological characteristics and when the increase in connectivity between floodplain environments facilitates the larval dispersion of this non-native species into other environments.

Key words: Propagule pressure, Invasion, Bivalve reproduction, Spermatogenesis, Oogenesis.

Citation: Tos CD, Cardim CA, Pereira VB, Mormul RP. 2021. Synchrony between reproductive phase and flood period: a dispersion mechanism for the freshwater clam Corbicula fluminea (Bivalvia: Corbiculidae) in a Brazilian neotropical floodplain. Zool Stud 60:3. doi:10.6620/ZS.2021.60-03.