Harpa harpa (Linné, 1758)
Top Left & Bottom - Length: 38.4mm, Width: 24.9mm, Height: 19.3mm. Under rubble and sand, ~80 ft. Facpi Point, Guam. 30 October 2005. Collected by Kevin Einmo.
Top Right - Length: 45.8mm, Width: 30.3mm, Height: 23.8mm. Dead, under rubble, less than 1 ft. Alupat Island, Agat Bay, Guam. 06 June 2005. Collected by Bob Abela.
Distribution: Indo-Pacific
Habitat: Intertidal to deep water, predominantly a sand dweller.
Availability: Rare on Guam
Size: Up to 75mm, Guam specimens are usually smaller
Comments: A well-documented behavior of Harpa is autonomy, where they seperate the rear portion of the foot when threatened by a predator. This too is noted in other gastropod families such as Cypraeids (subfamily Cypraeovulinae) and Trochids (subfamily Stomatellinae). The live specimen figured above did not fare well and died in the aquarium the day after collection. It did autonomize its foot though I can only speculate as for cause. It was in the same collecting jar as two Conus bullatus (a piscovore), so it's possible that one had stung it.
References:
Abbott, R. Tucker & S. Peter Dance. Compendium of Seashells. p. 211.
Cernohorsky, Walter O. 1972. Marine Shells of the Pacific. Vol. II. p. 68; pl. 1, fig 7.
Kay, E. Alison. 1979. Hawaiian Marine Shells. p. 284. fig 98 C.
Poppe, Guido T. & S. Peter Dance. 1999. The Family Harpidae. p. 9, 14. pl. 19, fig 1-9, pl. 20, fig. 1-7, pl. 42, 46, pl. 50, fig. 1.
Rehder, Harold A. 1973. The Family Harpidae. Indo-Pacific Mollusca 3(16):237-239. pl. 187, figs 7-10.
Springsteen, F. J. & F. M. Leobrera. 1986. Shells of the Philippines. p. 105; pl. 28, fig. 3.
Walls, Jerry G. 1980. Conchs, Tibias, and Harps. p. 151-152.
Wilson, Barry. 1994. Australian Marine Shells, Part Two. p. 137; pl. 30, fig 9a-b.
Links:
- Emmanuel Guillot de Suduiraut's Eurasia Shells - dark red 1 | dark red 2
- Hardy's Internet Guide to Marine Gastropods
- Machiko Yamada's Micro Shells
- OBIS Indo-Pacific Molluscan Database