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Spatial pattern of distribution and reproductive strategy of vermiculate electric‐rays Narcine vermiculatus
Author(s) -
TorresHuerta Ana María,
CruzMartínez Alicia,
RamírezChávez Eduardo Juventino
Publication year - 2021
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/jfb.14735
Subject(s) - vitellogenesis , biology , fecundity , sexual maturity , reproduction , spatial distribution , gestation , ovulation , zoology , ecology , pregnancy , oocyte , demography , fishery , embryo , population , mathematics , statistics , genetics , sociology
In the study, the authors evaluate the spatial distribution pattern of vermiculate electric‐ray Narcine vermiculatus using geostatistical techniques to predict its spatial distribution and indicate its reproduction strategy. From January 2008 to December 2009, 3333 specimens of vermiculate electric‐ray were caught. Total length ( L T ), sex, maturity stage, catch location and depth were recorded for each specimen. The L T of vermiculate electric‐ray ranged from 6.7–24.6 cm. The authors estimate an irregular spatial structure, with a high‐density patch ( x¯ = 53 ind. ha −1 ) located on the east coast, which concentrates 65.2% of the specimens. The high‐density patch consists mainly of large juveniles (13.3–19.5 cm L T ), sub‐adults (14.0–19.8 cm L T ) and young adults (14.7–21.3 cm L T ). Data indicate that adults migrate to the high‐density patch to reproduce. Males reached maturity at 14.5 cm L T , whereas females reached maturity at 19.3 cm L T . Vitellogenesis in female vermiculate electric‐ray begins in June; ovulation, mating, fertilization and gestation in October and birth begins in February. This indicates an annual cycle with vitellogenesis and consecutive gestation, in females synchronized in reproduction. Fecundity was 1–8 ( x¯ = 4), and the sex ratio of embryos was 1:1. The birth occurred between February and April, with an average size at parturition of 6.3 cm L T . Incidental capture of sub‐adults and adults of N. vermiculatus by bottom trawls threatens the survival of this species.