Nematodes in Trichomycterus nigromaculatus (Pisces: Trichomycteridae) from the Río Gaira, Sierra Nevada de Santa Marta, Colombia

Abstract

Objective. To determine the prevalence of helminth infection in Trichomycterus nigromaculatus captured in environments defined from the physicochemistry of the Gaira River, in Minca, Sierra Nevada de Santa Marta, Colombia. Material and Methods. We collected 476 specimens of T. nigromaculatus covering both climatic periods of the area, which were dissected to analyze the visceral cavity. Isolated parasites were fixed in 10% formalin for subsequent clarification. The specimens were identified by observation of adult stages under a stereoscopic microscope after clarification. Results. Specimens were found exclusively from the genus Spirocamallanus (Nematoda), the species Spirocamallanus sp. parasitic prevalence ranged from 0% in August to 28.57% in April with an abundance of 1.09 worms/host. Environmental parameters such as dissolved oxygen (Mean:5.65 mg. L-1, Max:7.5 mg. L-1, Min:4.41 mg. L-1); pH (Mean:7.2, Max: 9.3, Min: 5.7) and conductivity (Mean:72.82 µs.cm-1, Max: 123.7 µs.cm-1, Min: 40 µs.cm-1) presented statistically significant differences, the environment is eutrophicated. Conclusions. Spirocamallanus sp. were described in the areas of presence of the parasitic association in T. nigromaculatus, which constitutes a new record for the Colombian Caribbean and an extension of the geographic distribution and host range of the nematode.