RESEARCH ARTICLE Influence of habitat on the reproductive biology of the deep-sea hydrothermal vent limpet Lepetodrilus fucensis (Vetigastropoda: Mollusca) from the Northeast Pacific Noreen E. Kelly Æ Anna Metaxas Received: 17 August 2006 / Accepted: 2 October 2006 / Published online: 26 October 2006 Ó Springer-Verlag 2006 Abstract Habitat selection by the hydrothermal vent limpet, Lepetodrilus fucensis, in Northeast Pacific hydrothermal vent ecosystems, may influence its reproductive output, as it occupies habitats with vary- ing physico-chemical conditions that reflect the avail- ability of nutritional resources. Histological techniques were used to determine size at first reproduction, gametogenesis, reproductive output, and fecundity in relation to shell length (SL), through examination of the gonads of male and female L. fucensis, collected from five different hydrothermal vent habitat types with different temperature anomalies and hydrother- mal fluid flow vigour: vigorous (VIG), diffuse (DIF), tubeworm bushes (TWB), peripheral (PER), and senescent areas (SEN). Both male and female L. fuc- ensis exhibited early maturity, with the first reproduc- tive event occurring at 3.8 and 3.9 mm shell length, respectively. All stages of gamete development were present in the gonads of males and females, suggesting continuous gametogenesis and asynchronous repro- duction in this species. Gametogenic maturity of lim- pets did not vary among actively venting habitats (VIG, DIF, TWB, and PER), but was significantly lower in males and females from SEN habitats. Mean oocyte diameter was largest in females from VIG habitats, and smallest in females from SEN habitats, than in those from the other habitats (DIF, TWB, and PER). Females from actively venting habitats also had greater actual fecundity than those from senescent habitats. While the gametogenic pattern of L. fucensis appears phylogenetically constrained, selection of ac- tively venting habitats by L. fucensis maximizes its reproductive output. The multiple feeding strategies of L. fucensis may allow for a constant supply of energy to be allocated to reproduction in any habitat except senescent vents. Early maturity, high fecundity, and continuous production of gametes suggest a repro- ductive strategy characteristic of an opportunistic spe- cies, and may be contributing to the extremely abundant populations of L. fucensis observed in the Northeast Pacific vent ecosystem. Introduction Hydrothermal vent ecosystems are regions of the deep- sea with relatively intense biological productivity, hosting complex biological communities. Tectonic instability and volcanic eruptions in these systems can cause catastrophic perturbations to the associated communities. Invertebrate populations inhabiting these vents frequently experience large gradients in physico-chemical conditions that can vary spatially (10 cm–100 km) and temporally (days to decades) (Sarrazin et al. 1997). While the lifespan of an indi- vidual venting orifice can be short, vent fields can be active for decades (Tunnicliffe et al. 2003). Addition- ally, these unstable environments are fragmented, as individual areas of active venting are often separated by hundreds of kilometers along the mid-ocean ridges. Thus, the nature of hydrothermal vents is expected to favour species that have r-type life history strategies Communicated by R. J. Thompson, St. John’s. N. E. Kelly (&)  A. Metaxas Department of Oceanography, Dalhousie University, 1355 Oxford St, Halifax, NS, Canada B3H 4J1 e-mail: kellyn@dal.ca 123 Mar Biol (2007) 151:649–662 DOI 10.1007/s00227-006-0505-z