Nico, LG; Thomerson, J.E.; Dept. Zoology, 223 Bertram Hall, University of Florida, Gainesville, Florida, 32611 ACTA BIOL. VENEZ., vol. 12, no. 3-4, pp. 106-120, 1989
For those who are interested in more information on the habits and habitat of South American annual fish:
Sytopic associations among the six known Orinoco basin annual killifish were studied in four temporary pools in Portuguesa state, Venezuela. The species differe in adult size, body form and spatial distribution within the pools. Syntopic associations are among various combinations of a surface dwelling species, either Pterolebias hoignei or P. zonatus : and edge species Rachovia maculipinnis ; and midwater species, either Terranatos dolichopterus or Austrofundulus transilis or both. All species feed on insects and small crustaceans and ther is considerable diet overlap. The two surface species specialize somewhat on allochthonous insects; R. maculipinnis is a generalist; T. dolichopterus specializes on small crustaceans, and A. transilis preys heavily on both small crustaceans and aquatic insects. Pools are invaded by nonannual species, mainly characoids, during the rainy season. Annual species disappear while pools are well filled and food seems abundant. It was concluded that competition or predation by nonannual fishes is a major factor in eliminating adult annual fishes from these pools.
G.C.K.A. Newsletter – November 1996