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front, pale yellow


young, 7 mm

young, spotted

young shell

Aplysia juliana
Quoy & Gaimard, 1832
Aplysia juliana
Maximum size:  about 150 mm (most much smaller).

Identification:  This sea hare is usually light olive to brown with darker brown blotches on the sides of the parapodia. Younger animals are usually lighter in color with larger brown blotches. However, some may lack spots completely and/or have a pale yellow background. A line of white flecks often passes through the eye spot and there are sometimes white patches on the parapodia and rhinophore tips. The posterior portion of the foot forms a distinctive sucker.

Natural history:  Aplysia juliana is a moderately common species that is largely restricted to rocky habitats where there is an extensive growth of the green alga Ulva on which it feeds. It usually occurs at depths of < 1 to 2 m (< 3 to 6 ft) at protected to moderately exposed locations, often where there is some fresh water and nutrient seepage. Rarely, it may be found at other sites at up to 7 m (24 ft). It's nocturnal, concealing itself under rocks during the day. The posterior sucker on the foot allows it to cling to algae and rocks, crawling "inch-worm fashion." It ejects a milky white fluid when disturbed and lays a tangled, yellowish-brown egg mass that is usually attached to the underside of a rock.

Distribution:  Maui and Oahu (also Johnston Atoll?): circumtropical.

Taxonomic notes:  Aplysia sandvicensis Sowerby, 1869 is a synonym (Kay, 1979). It's referred to as "Juliana's sea hare" in Hoover, 1998 & 2006. It was first reported from Hawaii in Pease, 1860 (as Syphonota bipes) and is listed as Tethys bipes in Edmondson, 1946 and Ostegaard, 1950.

Photo:  CP: 100 mm: found by PF; on beach fronting Halama St., Kihei, Maui; March 12, 2011.

Observations and comments:

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