CLASSIFICATION OF DORIS (SEA LEMON)
KINGDOM :- ANIMALIA (Multicellular eukaryotic organisms)
PHYLUM :- MOLLUSCA (Unsegmented bilaterally symmetrical and provided with visceral mass, foot and mantle.)
CLASS :- GASTROPODA (Head bearing tentacles, eyes and radula; visceral hump and shell coiled due to torsion.)
SUB-CLASS :- EUTHYNEURA (Nerve loop not twisted in figure of 8.)
ORDER :- OPISTHOBRANCHIA (Gastropods with detorsion; gills posterior of heart; shell reduced or lacking)
SUB-ORDER :- NUDIBRANCHIA (Adults naked without mantle and shell.)
FAMILY :- DORIDIDAE
GENUS :- Doris
Cosmopolitan but specially found in the waters of New England.
HABIT AND HABITAT
Doris is a sluggish marine and curious gastropod found under stones at low tide mark and between weeds. It feeds on incrusting organisms like sponges
GENERAL CHARACTERSTICS OF DORIS (SEA LEMON)
- Commonly known as sea lemon.
- Body consists of more or less ovoid mass with a convex warm dorsal side.
- Colour is purplish brown.
- Head bears a pair of short retractile tentacles or rhinophores beset with calcareous spicules.
- Mantle is usually pigmented and contains calcareous spicules or dorsal tubercles.
- The anus lies mid-posteriorly and is surrounded by a circlet of feathered retractile secondary branchiae.
- Ventral surface has mouth, head, tentacle and mantles. Anus is surrounded by branchia or gills.
- Foot has a large creeping sole. Dorsal surface has protruding penis.
- Digestive gland unbranched compact mass and nervous system of euthyneurous type.
- Sexes are united and the gonopore is asymmetrically placed on the right side of the body.
The animal contains secondary retractile tentacles and all above features hence it is Doris.