Sexual dimorphism in two catfish species

[lfinley58]

Sexual dimorphism in two catfish species, Mystus pelusius (Solander, 1794) and Glyptothorax silviae Coad, 1981 (Teleostei: Siluriformes)
Hamid Reza ESMAEILI1,*, Golnaz SAYYADZADEH1, Mohammad AMINI CHERMAHINI2
1Ichthyology and Molecular Research Laboratory, Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
2Department of Fisheries, College of Natural Sciences, Behbahan Khatam Alanbia University of Technology, Behbahan, Khuzestan, Iran

Abstract: Sexual dimorphism of two catfish, Mystus pelusius (Solander, 1794) and Glyptothorax silviae Coad, 1981, is presented based
on the examination of external morphology of the fish and morphology of the gonads. We observed sexual dimorphism for M. pelusius
in the shape and position of the genital papilla. In the male, the genital papilla was a small, fleshy, pointed and broad-based structure.
The pelvic fin was short and did not reach back to the genital papilla. In females of M. pelusius the opening of the genital structure was
without any protrusion or with a very small, dot-like structure in a few specimens, which the pelvic fin reached and overlapped. In
females of G. silviae, the base of the round genital structure was wider and had a small round protrusion. The color of the female was also
darker in comparison with the male. In males the base of the round genital structure was narrower and had a longer pointed protrusion.
The male body color was lighter than that of females.
Key words: Siluriformes, sex differences, genital papilla, body color, pelvic fin

http://journals.tubitak.gov.tr/zoology/inpress.htm (In press but open access - item number 46).