Tiger Cowrie

Care

Tiger Cowries are beautiful,active omnivores known from shallow water reefs at depths of 10-30m (32-98ft).These fascinating creatures are largely nocturnal and are often observed at night moving between crevices, branched corals, and seaweeds in their ongoing search for food items. Tiger Cowries require a spacious, mature aquarium with plenty of macro and microalgae growth upon which to browse. Ensure that all rockwork is very secure, as large adults are capable of accidentally moving large objects as they blunder around the tank looking for nourishment. It is not unknown for these cowries to live more than 10 years under good conditions,and as well as looking so eye-catching, they can also prove to be very functional additions to the aquarium. There is some debate as to whether TigerCowries can be considered totally reef-safe, as experiences do seem to vary from aquarist to aquarist - therefore much caution is advised before adding these creatures to an aquarium containing prized sessile invertebrates. Onceacclimatised, careful observation is key, as is a good, varied and plentiful diet, as this will help to ensure that corals and sponges are not continually targeted. Some experts suggest that juvenile Tiger Cowries are much more herbivorous compared to the adults, which might account for the many different experiences and opinions.The shell of these cowries is roughly egg-shaped and is large and heavy. The striking dorsal surface is white to buff in colour and densely covered with dark brown to black spots. As with many other Cypraea species, the surface of the shell is incredibly shiny, almost as if it has been highly polished. Some specimens show a blurred redline along the length of the shell at the dorsal midline. There is no sharp margin between the upper and lower surfaces, as is seen in many other cowries,and the ventral side of the shell is white and the opening lined with tooth-like serrations. Fascinatingly, two lateral extensions of the soft mantle are able to extend so as to cover the shell completely, meeting at the midline of the dorsal surface. This veil-like mantle is often fully expanded when the cowrie is on the move, and the exterior surface has numerous short, white-tipped papillae radiating from it. Raising the mantle in this manner is thought to stop encrusting creatures from settling on the shiny surface of the shell. When threatened, or when resting, the Tiger Cowrie can completely withdraw the mantle into the shell opening. The specimen pictured above was photographed just as it had begun moving around the aquarium after resting, so the mantle had just started rising up onto the glossy shell. Tiger Cowries may be kept in goodsized groups, providing space allows. Tankmates should be small and peaceful,and avoid keeping with large, predatory fish or with Atlantic anemones (Condylactis spp.). Blue moon lighting will allow the aquarist to view the cowries" antics late into the evening. It is important to keep water quality high at all times as this species will not tolerate an elevated nitrate level. Never use copper-based treatments in aquaria containing invertebrates. Sadly, these cowries have become quite scarce in the shallower parts of their range (0-10m) due to over-harvesting for the tourist trade, whereby masses of the shells are sold as ornaments. It is thought that the majority of these cowries now inhabit areas from 10-30m, which thankfully is not quite as freely accessible to collectors. Tiger Cowries has not been evaluated for IUCN red list status.

Feeding

Omnivorous. Juveniles prefer green-based foods such as marine algae and Spirulina, whereas adults enjoy a larger proportion of meatier fare. Offer vitamin-enriched Mysis shrimp, krill, and chopped fish/mussel/cockle/prawns, etc. Algae-covered rocks can be culture in a fishless refugium and rotated with rocks within the main aquarium to provide an ongoing supply of green foods.

Breeding

Tiger Cowries have not been bred in the home aquarium, although some aquarists have seen females protecting egg masses. This species has a veliger (planktonic) stage that makes them very difficult to raise in captive conditions. Once the plankton undergoes settlement in the benthic habitat, the juveniles increase their soft-body volume while forming a fragile, coiled shell. At the end of the juvenile stage, cowries experience a second metamorphosis in which the shell coiling ceases and the shell aperture narrows. During the next stage, calcareous material is deposited on both the lateral exterior and dorsal interior surfaces of the shell that was constructed during the juvenile stage (referred to as the juvenile shell) to thicken a "callus" that appears to serve as a defense against predators. The size of the juvenile shell and the volume of the soft-body does not increase after the juvenile stage (this is known as explicit determinate growth). Reproduction begins after the end of the callus-building stage.