Etho-Ecology of Seventeen Barbus Species (Pisces; Cyprinidae)

Abstract

Barbus species greatly differ among each other in the structure of reproductive behaviour. Two distinct types have been described. Non-territorial spawning aggregations and male spawning territories are their typical traits (KORTMULDER, 1972). Most species do not fit either of these types. They are also not intermediate. The present paper seeks an enlarged typology to include all species. Two paths are followed (see Fig. 3) leading to ecological and (functional) ethological typologies respectively. To arrive at an ecological typology, first male and female reproductive strategies are delineated. From the strategies follow 3 parameters which are relevant for classifying habitats. The parameters are all concerned with homo/heterogeneities of the environment in time or space. They lead to 12 habitat types, 5 of which are subsequently discarded as being improbable. Ecological types of Barbus are then derived by tracing to what extent the strategies delineated first may be realized in each of the 7 remaining habitat types. To arrive at an ethological typology, the various traits of each of 17 species (as observed in the laboratory) are mapped. Functional interrelationships between traits are indicated. For each species a trait is sought, i.e. a primary adaptation surrounded by secondary adaptations. The central traits are listed and classified. The resulting ethological typology is compared with the ecological one. With a small number of amendments the two typologies are shown to be nearly identical. In conclusion of the paper, the results are discussed against a background of fish communities, Barbus taxonomy and existing literature on other groups. Some attention is given to ways of testing the hypotheses developed in the paper.