Meeting Abstract
P1.14 Jan. 4 White exudate of the West Indian topsnail, Cittarium pica (Vetigastropoda: Trochidae) HICKMAN, Carole S; COATES, Kathryn A*; Univ. of California, Berkeley; Bda Dept. Cons. Services kcoates@transact.bm
Fluid exudates in marine mollusks are best known from taxa that lack shells; extensively studied compounds are the “inks” from octopus, cuttlefish, and squid. Their clouds of ink may perform several different roles – visually distracting or confusing predators, chemically alerting conspecifics to danger, and interfering chemically with chemoreception by predators. The West Indian topsnail, Cittarium pica, secretes an opaque white liquid when disturbed. This was interpreted originally as a warning substance that elicited an alarm response in nearby topsnails. Subsequently, the liquid was reinterpreted as a cloud of broadcast sperm. We investigate populations in Bermuda in an effort to determine whether C. pica does release an opaque fluid distinct from sperm, the conditions under which the exudate is produced, and the distribution of release by individuals. Lines of evidence from our studies indicate that the exudate is distinct from broadcast sperm: (1) Exudate is produced by significantly more than half of the individuals in a population, (2) Exudate is produced in response to physical disturbance and appears after the animal has completely withdrawn into its shell, (3) Exudate does not contain sperm, and (4) Exudate is produced by animals that are reproductively immature and lack a male gonad. The site (or sites) of origin of the exudate (or exudates) is being explored. Three important reasons to resolve conflicting interpretations of the white fluid of C. pica are to contribute to knowledge of the basic biology of a species targeted for conservation and management efforts throughout the Caribbean; to establish greater awareness of the structurally and functionally overlooked white exudates of basal gastropods; and to explore the expediency of light microscopy and anatomical dissection as tools for initial characterization and differentiation of exudates.
