UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

A review of the genus Caranx from the tropical east Pacific Lane, E. David

Abstract

Seven Caranx species occur in the tropical east Pacific. C. caballus (61 specimens examined) is separable from the Atlantic form C. crysos (10 specimens examined) by a character index. C. marginatus (64 specimens examined) is separable from the Atlantic form C. latus (5 specimens examined) and the Indo-Pacific form C, sexfasciatus (2 specimens examined) by vertebral count. C, hippos (58 specimens examined) occurs on both sides of the Panama Isthmus. C. lugubris (28 specimens examined) is circumtropical. C. melampygus (37 specimens examined) is synonymous with C. stellatus. C. medusicola (3 specimens examined) is endemic to the east Pacific region, as is C. vinctus (22 specimens examined). Caranx species in the tropical east Pacific comprise: 2 circumtropical species (C. hippos and C. lugubris); 1 Pan-Pacific species (C. melampygus) and 4 endemic species (C. caballus, C. marginatus. C. vinetus and C. medusicola). Barriers to Caranx distribution in the east Pacific are: temperature to the north and south; the Panama Isthmus to the east; and the east Pacific sea barrier to the west. Some forms vary to the extent of specific difference over their range (C. caballus : C. crysos and C. marginatus : C. latus : C. sexfasciatus) while others are very similar over their entire range (C. lugubris and C. melampygus). C. hippos is intermediate in variability between these extremes. Probable reasons for paucity of the tropical east Pacific fauna are the presence of barriers to invasion, especially the east Pacific sea barrier and the lack of coral reef habitat. On the basis of Caranx evidence it is unlikely that the postulated 3 to 4C° Pleistocene temperature drop had a serious effect on the fish fauna.

Item Media

Item Citations and Data

Rights

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.