Cancellariidae
Housing of Trigonostoma milleri
The lattice snails ( Cancellariidae ) are a family rather small to medium sized, exclusively marine snails that are found in tropical to cold seas worldwide. As far as known, all representatives as temporary ectoparasites feed on clams, snails and fish blood or suck eggs and egg capsules from. About 300 species have been described.
Features
The dextral, oval to spindle-shaped housing of the grid snails have a thread with a stair -stepped whorls. The surface of the case is due to the axial and spiral running sculpturing line- up grid form. The columella usually has varicose veins, but can also be imperforated. The finished snails have no operculum, but this is detectable in the veliger larvae.
The Cancellariidae have a long, thin proboscis, in which there are the salivary glands. The highly specialized radula is well within the proboscis directly in front of Leiblein flap. As with the Conoidea the front esophagus is re-formed. The intestinal canal is greatly simplified, which can be explained by the liquid diet. The Dorsalfalten protrude far into the esophagus and almost to the stomach.
The animals are dioecious with internal fertilization. The eggs are attached in egg capsules on the ground. In some of the species of plankton slip -eating, free-swimming veliger larvae that metamorphose later into small snails, while in others the larval development in the capsules expires, so that finished young snails hatch.
Life, the occurrence and distribution
The Cancellariidae are found worldwide, mainly in tropical and subtropical, partly temperate to cold seas. They live mostly on soft ground from the intertidal zone to depths of about 1000 meters.
The most studied so far Cancellariidae suck shells and sand-dwelling worm blood while Cancellaria cooperi this to torpedo does ( O'Sullivan, McConnaughy and Huber, 1987). To this end, seek their host snails in its resting phase and stab him with her thin, far beyond the length of the body also extendable proboscis to suck his blood. Other types pull eggs of different marine animals before as food; so they suck for example egg capsules of snails.
System
After Bouchet and Rocroi (2005 ) the family Cancellariidae simultaneously forms the superfamily Cancellarioidea within the Neogastropoda. Criterion for establishing a separate superfamily are the lack of a Leiblein gland and poison gland. You divide the family Cancellariidae into three subfamilies: Plesiotritoninae, Admetinae and Cancellariinae.
A cladistic analysis at the molecular genetic basis by Modica, Bouchet, cruaud, UTGE and Oliverio (2011) suggests that the subfamily is monophyletic Plesiotritoninae while the subfamilies Admetinae and Cancellariinae be regarded as polyphyletic. The authors see as a revision of the genera Nipponaphera, Merica, Sydaphera and Bivetia as necessary.