Intraspecific variation in external morphology of the sand skate

BRACCINI, M.; CHIARAMONTE, GUSTAVO ENRIQUE

Journal of Fish Biology

The Fisheries Society of the British Isles

Lugar: London; Año: 2002 vol. 61 p. 959 - 972

0022-1112

In male sand skate Psammobatis extenta, from the commercial fishery of Puerto Queque´n,Argentina, six of 13 proportional dimensions analysed were constant (isometric) with totallength, while seven proportions remained constant in females. The nature of the allometric andisometric relationships of disc length, disc width, interspiracular distance and interorbitaldistance did not vary between the sexes, and no sexual dimorphism occurred between thesemorphometric dimensions. A stepwise discriminant function analysis separated the sexes andwas able to correctly classify 90·8% of the original grouped cases. The variables that bestdiscriminated between sexes were prenasal length, distance from the cloaca to caudal fin tip,and distance from the snout to cloaca. The study also revealed that several of the meristiccharacters studied showed much intraspecific variation and, therefore, should be used withcaution in taxonomic studies.