Feeding and reproductive biology of the currito, Hoplosternum littorale, in the Venezuelan llanos with comments on the possible function of the enlarged male pectoral spines

Abstract

For one year, Hoplosternum littorale were sampled monthly from Cano Maraca, a seasonal swamp-creek of the western llanos of Venezuela. H. littorale exhibited a more or less synchronized burst of reproductive activity that coincided with the onset of the rainy season. Spawning was preceded by gradual gonadal recrudescence and a decline in visceral fat deposits during the 5 month dry season. The species is sexually dimorphic with adult males being of larger average size, attaining a larger maximum size, and possessing elongate, recurved pectoral spines and fat deposits on the pectoral fins just prior to and during the spawning season. Aquarium observations revealed that male H. littorale can use the enlarged pectoral spines as weapons during aggressive attacks. This form of aggressive behavior is most likely a component of the brood defense behavior of the species. Both immature and adult H. littorale were microphagous scavengers, taking a variety of food items from the soft mud substrate. Aquatic microcrustacea were the major item in the diet of immature fish. During the late wet and dry seasons, 61% of the stomachs sampled were empty and the intestines air- filled, indicating active use of the gut for aerial respiration.