| Remarks |
Collected from a small brook, about 0.5 to 1 m wide, that flows into a tributary to the río Tacotalpa, close to a bridge, a few hundred meters on an unpaved road that branches off into northeasterly direction from the main road from Tapijulapa to Jamapa between the small settlements of Zunu y Patastal and Madrigal (Cuarta sección). At the time of collection, at late afternoon the water had a temperature of 26 °C, a conductivity of 360 mS, pH 8.0, and total hardness of 10-15. The water was crystal clear and fast flowing with no aquatic vegetation. The substratum consisted mainly of gravel and sand. The brook flows in a deep indentation and is fully shadowed by the vegetation. Associated poeciliid fishes were Pseudoxiphophorus bimaculatus, Gambusia sp., Heterophallus milleri, Poecilia mexicana and a characid, Astyanax mexicanus (Ref. 57748). |