Vermetid snail (pest) (Dendropoma maxima) care guide

Group
Snails
Other names
Ceraesignum maximum, Dendropoma maximum, Vermetid, Worm snail, Mucus-net snail
Family
Vermetidae
Origin
Coral reefs of the Indian and Pacific Oceans
Water
saltwater
Reef safe
no

Care

Vermetid snails are reef pests, not livestock: they should not be sold. The name on this page, Dendropoma maxima, is a misspelling of Dendropoma maximum, which is now placed in the genus Ceraesignum as Ceraesignum maximum. It is a large Indo-Pacific vermetid, one of many species of 'worm snails' whose shells are cemented to rock or coral as an irregular tube rather than a free coil. How it arrives: as tiny larvae or young snails on live rock, coral frags and colonies, and on rock from other people's tanks. Once in a tank, smaller vermetids can breed and spread over rock and glass. How to identify it (general hobby guidance, not from our sources): a hard, white-to-grey, chalky tube, often coiled or wandering, fixed to rock, glass or coral, from a few millimetres up to several centimetres. The animal stays inside and casts out sticky threads of mucus that drift on the water. Feather dusters and Christmas tree worms look different: they extend feathery crowns, not strands of slime. Harm done: the mucus nets lie over neighbouring corals, irritating them so that polyps stay closed and stony corals (especially Acropora, Montipora and other SPS) lose tissue, colour and growth. Removal and prevention: inspect and quarantine new rock and corals; remove any vermetid tubes before adding frags (coral dips will not kill established vermetids). In the tank, crush the tube with pliers or a stiff tool, or fill the opening with superglue or two-part epoxy so the snail suffocates; remove badly infested frag plugs. Keep feeding moderate, as excess food fuels them. Few natural predators reliably eat them, although some keepers report help from certain fish. Copper-based medicines and some plant fertilisers are toxic to shrimp, snails and most invertebrates. Sources: Wikipedia (en.wikipedia.org/wiki/Dendropomamaximum, now Ceraesignum maximum). Checked October 2026.

Diet

Vermetids feed by spreading sticky mucus threads or nets into the water, trapping plankton and organic particles, then hauling the net back in and eating it with its catch. In aquaria they thrive on heavy feeding, broadcast plankton foods and coral foods.

Breeding

General guidance, not from a source: vermetids brood their eggs inside the tube and release larvae or crawling young that settle nearby, which is why small vermetids can multiply in an aquarium once established.

Compatibility and tank mates

Harmful in reef tanks: the mucus nets irritate and damage nearby corals, particularly small-polyp stony corals. Not a clean-up snail and should never be added deliberately.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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