Many cone snails are venomous. The venom is a neurotoxin used to immobilise their prey. These snails should not be handled while the animal is alive unless you are an expert.
Striate cone below is found in the Indo-Pacific in sand and under coral. Fully grown its length reaches around 11.5 cm. It emerges at night to hunt fish and worms.
Left, the Prometheus cone or Butterfly cone, Conus prometheus. Found in the Eastern Atlantic and Mediterranean. Size around 140 x 65 mm.
Tesselate cone, Conus tesselatus, on the right has a length of 6.5 cm when fully grown. It is found in the Indo-Pacific region up to 20 m deep in sheltered environments around coral reefs where it burrows into the sand. It is predatory and venomous.
The Beech cone, Conus betulinus, on the right
Marbled cone, Conus marmoreus on the right. is found in the Indo-Pacific, from 1 - 30 m deep, in lagoons on coral reefs, sand, under rocks and in weeds. It is found in the Indo-Pacific region. Its venom is strong enough to kill an adult human. It feeds on various invertebrates including other cone snails. Fully grown specimens are about 15 cm long.
Zigzag nerite, Neritina communis on the right are found in the Philippines and western Pacific, often among mangroves. As can be seen in the photograph the colours and patterns are very variable.