Melanochlamys cylindrica
Cheeseman, 1881

Order: CEPHALASPIDEA
Superfamily: PHILINOIDEA
Family: Aglajidae

DISTRIBUTION

New Zealand. [North & South Islands]

PHOTO

Auckland, New Zealand. Photo: Gary Batt.

The animal is totally black, sometimes with a bluish sheen when the light catches the beating cilia, which cover the skin, at a certain angle. In Cheeseman's (1881) original description of the genus Melanochlamys he differentiated the genus from Aglaja on the external form of the body noting that 'the side lobes of the foot [are] losely appressed to the sides of the animal, and [are] not spreading'. In live material it is possible to disnguish members of the genus by the shape of the body. It is usually cylindrical, the parapodia small and tightly held against the sides of the body. The posterior end of the head shield is rounded, sometimes with a median indentation, and held flat against the dorsal surface of the posterior shield over which it only just overlaps. There are no processes developed from the posterior end of the posterior shield, although there is usually a dorsal median indentation or notch. Melanochlamys cylindrica, like all members of the genus has a large muscular buccal bulb which fills the anterior half of the body cavity. It is a specific feeder on polychaete worms which it captures by rapidly sucking them in like a piece of spaghetti - the buccal bulb acting as a suction pump. Like most aglajids, it lacks a radula. It grows to about 30mm in length, and is usually found in algal turf on rock platforms.

References:
• Cheeseman, T.F. (1881) On a new genus of opisthobranchiate Mollusca. Transactions of the New Zealand Institute, 13: 224.
• Rudman, W.B. (1968) Three new species of the opisthobranch family Aglajidae from New Zealand. Transactions of the Royal Society of New Zealand (Zoology), 10(23): 211-216.
• Rudman, W. B. (1972) Structure and functioning on the gut of the Bullomorpha (Opisthobranchia). Part 4. Aglajidae. Journal of Natural History, 6(5): 547-560, 8 figs.
• Rudman, W.B. (1972) On Melanochlamys Cheeseman, 1881, a genus of the Aglajidae (Opisthobranchia: Gastropoda). Pacific Science, 26(1): 50-62, 8 figs.
• Rudman, W. B. (1972) Structure and functioning on the gut of the Bullomorpha (Opisthobranchia). Part 4. Aglajidae. Journal of Natural History, 6(5): 547-560, 8 figs.

Authorship details
Rudman, W.B., 2003 (May 11) Melanochlamys cylindrica Cheeseman, 1881. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/melacyli

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