Breeding the Textile Nerite (Nerita textilis)
Nerita textilis is a marine intertidal nerite with separate sexes that lay egg capsules on rock. The eggs release planktonic veliger larvae that disperse in the sea and cannot mature in a reef tank.
Overview
Nerita textilis Gmelin, 1791, the textile nerite, is a marine gastropod of the family Neritidae. The shell grows to about 5 cm and bears broad, ridged spiral cords. It lives on rocks in the littoral fringe of the Red Sea and the Indo-Pacific, including Aldabra, eastern South Africa, Kenya, Madagascar, Mozambique and Tanzania. Nerites are gregarious herbivores, and their appetite for film algae makes them effective marine grazers in reef tanks.
Sexing
Nerites are gonochoristic, with distinctly male and female individuals, but they cannot be sexed externally by shell. Fertilization is internal following copulation, yet a keeper cannot select pairs by appearance.
Spawning & Larvae
After mating, females deposit flattened egg capsules on hard, rocky substrate, each capsule containing multiple eggs. The eggs hatch into planktonic veliger larvae that feed on plankton; in Nerita species the larvae may spend up to about six months in the plankton, giving broad dispersal across coasts.
Common Challenges
- Egg capsules may be laid in a tank, but the planktotrophic veligers cannot complete development in closed water.
- A planktonic phase of up to roughly six months is impossible to support in an aquarium.
- Larvae are drawn into skimmers, filters and pumps and need plankton-grade food.
- Marine nerites differ from freshwater nerites only in salinity, not in their planktonic, non-home-bred life cycle.