PATTERNS IN SPECIES RICHNESS, SIZE, AND LATITUDINAL RANGE OF EAST ATLANTIC FISHES

Examination of latitudinal patterns in species richness, size, and distributional range of East Atlantic fish, based on a compilation of data encompassing the full latitudinal and depth distribution of 1746 East Atlantic fish species, showed that species richness declined towards higher latitudes at a rate of c. 1% of the number of species present, in five-degree bands, for each degree of latitude for both teleosts and elasmobranchs, regardless of habitat. However, the latitudinal patterns in maximum fish size and latitudinal range differed between teleosts and elasmobranchs, and changed with habitat. No clear evidence was obtained that the latitudinal range occupied increased with latitude, indicating that Rapoport's rule does not apply to E Atlantic fishes. Rather, the latitudinal patterns in species richness, size, and distributional range of benthic Atlantic fish were depth-dependent, because species richness, average maximum size, and the average latitudinal range increased with depth, and declined with latitude. The importance of accounting for this depth-latitude covariation in the distribution of marine fish demonstrated here, together with recent evidence obtained for deep-sea benthic macrofauna, points to depth and latitude as the main factors in the distribution of marine animals.