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Reproduction of the A tlantic bobtail squid S epiola atlantica ( C ephalopoda: S epiolidae) in northwest S pain
Author(s) -
Rodrigues Marcelo,
Guerra Ángel,
Troncoso Jesús S.
Publication year - 2012
Publication title -
invertebrate biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.486
H-Index - 42
eISSN - 1744-7410
pISSN - 1077-8306
DOI - 10.1111/j.1744-7410.2011.00253.x
Subject(s) - biology , reproduction , population , ecology , zoology , reproductive biology , juvenile , sexual dimorphism , chondrichthyes , sexual maturity , fishery , embryo , demography , sociology , embryogenesis
A tlantic bobtail squid ( S epiola atlantica ) in northwest S pain show seasonal variation in population structure, with juvenile abundance peaking during summer and autumn. However, whether similar patterns exist for reproduction is unknown. Therefore, we describe the reproductive biology of 505 specimens of S . atlantica collected monthly during two consecutive years at two different sites off of A reamilla beach in the R ía de V igo. Mature males displayed a type of sexual dimorphism previously unknown in members of this species, developing a muscular nodule in the base of each of the ventral arms over ontogeny. Reproductive output of both sexes was similar to that of other bobtail squids. Relative oocyte size (~10% mantle length) appeared to be similar to those of other bobtail squids. Females did not show evidence of having mated before complete maturity. Females of S . atlantica have group‐synchronous ovary maturation, with a positive correlation between female mantle length and ripe oocyte mass, suggesting a terminal investment strategy. Atlantic bobtail squids displayed the same seasonal patterns of reproductive traits at both sampling sites, with significant differences in reproductive activity between males and females. We consider reproductive traits in these small animals as adaptations to the coastal shelf lifestyle.