Size at the onset of sexual maturity in the anomuran crab, Aegla uruguayana (Aeglidae)

Abstract

 Abstract Viau, V. E., López Greco, L. S., Bond-Buckup, G. & Rodriguez, E. M. 2006. Size at the onset of sexual maturity in the anomuran crab, Aegla uruguayana (Aeglidae). -Acta Zoologica (Stockholm) 87 : 253-264The size at maturity was studied in the crab Aegla uruguayana from the Areco River (31 ° 14 ′ S, 59 ° 28 ′ W), Argentina. Size at sexual maturity was determined according to three criteria: morphometric (change in the relative growth of reproductive characters), histological (first maturation of gonads) and functional (capability to mate and carry eggs). Regarding females, morphometric maturity occurred at a carapace length (CL) of 11.50 mm, considering abdomen width as a reproductive character. Gonad maturity of females could be observed at a minimum size ranging from 15 to 17 mm CL. The smallest ovigerous female observed in the field was 15.60 mm CL, although a relevant population incidence of ovigerous females (86.6%) has just been observed at values higher than 17 mm CL. As for males, the relative growth of the left chela length changed at a value of 15.40 mm CL, while morphological changes in sexual tube occurred between CL of 14 and 16 mm. Testicular maturation occurred at a CL ranging from 17 to 19 mm. The smallest size of males having spermatozoids in their vasa deferentia was 18.70 mm CL. The results obtained indicated that, in both sexes, functional maturity occurred after morphometric maturity and at a size similar to that of gonad maturity. Comparing sexes, females acquired sexual maturity (morphometric, gonad and functional maturity) at sizes statistically smaller than those of males.

Maturidade sexual morfológica de Aegla platensis (Crustacea, Decapoda, Anomura) no Lajeado Bonito, norte do estado do Rio Grande do Sul, Brasil

“…Assim como no presente estudo, foi verificado que as relações CC x comprimento dos quelípodos são as que apresentaram melhores respostas na avaliação de maturidade em machos e em fêmeas a melhor relação foi LA x CC. VIAU et al (2006), ao estudarem indivíduos de A. uruguayana provenientes do rio Areco, na Argentina, estimaram a maturidade sexual morfológica de fêmeas em 11,5 mm. Porém, esse valor é inferior ao obtido pela observação de gônadas, estimado entre 15 e 17 mm de CC.…”

Allometric growth, sexual maturity and reproductive cycle of Aegla castro (Decapoda: Anomura: Aeglidae) from Itatinga, state of São Paulo, southeastern Brazil

“…The former is associated with the puberty molt and marks the transition from the juvenile into the adult phase, whereas the latter refers to sexually matured individuals that successfully take part in the reproductive process (see López-Greco and Rodríguez, 1999 for review on sexual maturity in decapods). Allometric growth analysis has been often employed in determining the average size at the onset of morphometric maturity of aeglids species (Colpo et al, 2005;Viau et al, 2006;Bueno and Shimizu, 2009;Oliveira and Santos, 2011;Trevisan and Santos, 2012;Copatti et al, 2015).…”

Shape and size variations of Aegla uruguayana (Anomura, Aeglidae) under laboratory conditions: A geometric morphometric approach to the growth

“…In this context, we could identify the degree of the shape change during growth in different regions of the cephalothorax. These differences could reflect internal growth (e.g., gonad and muscle) or hierarchy and agonistic behaviour in the population (e.g different dimensions in cephalothorax, armament and chelae) (Williner & collins, 2000;colPo et al, 2005;giri & collins, 2004;ViAu et al, 2006;Ayres-Peres et al, 2011). Furthermore, differences in the growth of shape across several species could provide information regarding group evolution or interaction with the environment (hArtnoll, 1982;collins et al, 2007).…”

“…Specimen were separated into three categories, juveniles (N = 45; LC range: 2.99-10.71 mm), males (N = 13; LC range: 12.21-28.66 mm) and females (N = 8 non-ovigerous; LC range: 12.05-19.02 mm) according to cephalothorax length (LC) following the sexual maturity criteria outlined by ViAu et al (2006).…”