We have seen at least 25 specimens of Halgerda tessellata at Enewetak and Kwajalein Atolls, and another was recorded from Rongelap by John and Lynette Flynn. It typically lives under dead coral on lagoon pinnacles, although a couple of specimens have been found on the seaward reef under rocks in surge channels. Most have been at depths of 9 to 15 meters, and ten individuals ranged in length from 8 to 17mm. An egg mass deposited in captivity contained orange yellow ova measuring about 190µm individually within capsules about 240µm in diameter. There were about 50 ova/mm squared and 4000 in the three loose whorls deposited by a 15mm individual. The eggs hatched in 5 days as free swimming veligers with Type 1 clear tan shells with deep brown columellae. Halgerda tessellata was first reported in the Marshalls from Enewetak Atoll as Halgerda wasinensis by Johnson & Boucher (1984).
An especially dark individual.
With egg mass.
The one below happened to be crawling across a bryozoan colony.
The specimen in the three photos below was found in a Kwajalein Atoll lagoon Halimeda patch at a depth of 8m on 7 June 2009. In the first, it had crawled onto a sponge for the photograph, but we don't think this is its prey species.
The two photos below was a 25mm specimen found under a rock on a Kwajalein lagoon reef on 19 July 2010.
Bottom of foot.
Although specimens from the Marshalls all resemble each other, they look somewhat different from specimens from Pohnpei or the Solomons.
Created 12 December 2006
Updated 7 November 2021