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Cephalopyge trematoides
(Chun, 1889)
Cephalopyge trematoides
Maximum size:  about 25 mm.

Identification:  The body of this species is elongate and streamlined, tapering to a blunt "tail." On the head are two smooth, contractile rhinophores and a small rostrum is present. The foot, which is reduced to a small ventral projection toward the anterior end, is capable of extending and contracting. Through the transparent body can be seen the reproductive and digestive glands that may vary in color. A few white flecks may be present along the dorsal and ventral margins as well as on the rhinophores.

Natural history:  Cephalopyge trematoides is rarely seen due to its small size, transparent body and planktonic habit. The single animal we've seen on Maui was found in open water at 12 m (40 ft). Adults may be free-living and swim by means of lateral undulations as fast as seven undulations per second. These waves, which run from the head to the tail, can propel the animals forward at a rate of 12 cm/second. They may also attach to their prey using a pedal gland. They feed on the siphonophores Nanomia bijuga, Halistemma sp. and Stephanomia sp. A cylindrical egg strand is laid in the water column. (Lalli & Gilmer, 1989)

Distribution:  Big Island, Maui and Kauai: circumtropical.

Taxonomic notes:  The genus name refers to the location of the anus (-pyge) on the dorsum directly behind the head (cephalo-).

Photo:  PF: 14 mm: found by Andy Schwanke; Alalakeiki Channel, Maui; Oct. 17, 1998.

Observations and comments:

Note 1:  ( )
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