Tuesday, December 1, 2015

[Ichthyology • 2015] The Microhabitat, Behavior and Diet of Centromochlus meridionalis, A Small Catfish of Amazon Streams (Teleostei: Auchenipteridae)

Fig. 1. Centromochlus meridionalis photographed alive in aquarium. a, female, 60.2 mm SL; and b, male, 53.2 mm SL (ABAM I-00398). Arrow indicates modified anal fin forming the intromittent organ. (Photographs L. N. Carvalho and F. G. Cabeceira).
Fig. 2. Illustration of behavioral acts performed by Centromochlus meridionalis: a, resting between leaves; and b, feeding at the bottom in head-down posture. For a description of the behaviors see Table 1. (Illustrations by Cristiane C. de Freitas).

Centromochlus meridionalis was recently described from streams of Brazilian Amazon. The marbled dark brown and black color pattern together with the use of submersed leaf litter accumulations for shelter differentiates this species among its congeners. We present information about the biology of C. meridionalis based on data gathered in streams and under captivity, as well as on a dietary analysis. Behavioral observations were made in captivity (aquaria). Dietary analysis was performed based on stomach contents of 38 specimens. The species was found in 8 out of 12 small streams sampled, where specimens were captured predominantly amidst submerged leaf litter. Nine types of behavioral acts were identified, of which “swimming near the substratum” and “charging the substratum for food” were the most frequent. Thirty (~79 %) out of the 38 stomachs had food, and the diet was composed of 27 types of food items. Centromochlus meridionalis can be considered a generalist microcarnivore, consuming predominantly authochtonous and allochtonous insects, and other terrestrial invertebrates, crustaceans and fish as well. The use of different water column strata during foraging and the diversity of food items consumed indicate that this small catfish utilizes several feeding tactics.

Cabeceira, Fernando Gonçalves, Denise Caragnato Parisotto, Jansen Zuanon, Alberto Akama and Lucélia Nobre Carvalho. 2015. The Microhabitat, Behavior and Diet of Centromochlus meridionalis, A Small Catfish of Amazon Streams (Teleostei: Auchenipteridae). Ichthyological Exploration of Freshwaters. 26(3); 221-228. http://www.pfeil-verlag.de/04biol/pdf/ief26_3_03.pdf