Colonisation of newly-opened habitat by a pioneer species, Alvinella pompejana (Polychaeta: Alvinellidae), at East Pacific Rise vent sites

Abstract

Animal communities on the walls of deep-sea hydrothermal chimneys are distributed in mosaics of patches that may evolve as local environmental conditions change and biological interactions develop. Alvinella pompejana Desbruyères et Laubier, 1980 is one of the first metazoan colonisers of new surfaces created by mineral precipitation, and therefore may be particularly important in community establishment in active parts of smokers. Here our goal was to investigate the colonisation mechanisms of A. pompejana in new patches and determine whether these mechanisms may influence population structure and reproductive patterns in this species. We deployed a series of TRAC (Titanium Ring for Alvinellid Colonisation) devices at East Pacific Rise (EPR) vent sites to compare the size and stage (i.e. reproductive maturity) distribution of A. pompejana individuals between recently colonised patches (TRACs) and established patches (grabbed by submersible). TRACs deployed for short time periods (11 d to 1 mo) were generally colonised by smaller individuals than those found in background populations or in TRACs deployed for longer time periods (>1 mo). Colonists into new patches were a mix of juveniles and individuals that were sexually mature but non-reproductive (i.e. not producing gametes), whereas background population and older patches harboured a mixture of individuals at different stages including reproductive females. Although some individuals may have recruited on TRACs as larvae, the major colonisation process involved was probably immigration of post-larval stages. In long-term TRAC, reproductive females were not reproductively synchronised. In this dynamic environment, reproduction would be triggered by the disturbance/migration processes, explaining the heterogeneity observed in reproductive patterns.

Biogeography, Ecology, and Vulnerability of Chemosynthetic Ecosystems in the Deep Sea

“…Since 2002, studies have focused on vents, seeps, whale and wood falls (see, for example, Mullineaux et al 2003 ;Govenar et al 2004 ;Pradillon et al 2005 ;Levin et al 2006 ;Braby et al 2007 ;Kelly et al 2007 ;Fujiwara et al 2007 ;Tyler et al 2007 ;Arellano 2008 ). In all habitats, larvae of different species settle and colonize areas in a particular sequence that appears to be related to chemical and biological cues of the environment.…”

Spatial and temporal dynamics of reproduction and settlement in the Pompeii worm Alvinella pompejana (Polychaeta: Alvinellidae)

“…They all showed peculiar adaptive convergence on reproductive mode and larval development. Indeed, most of them display continuous oogenesis (McHugh 1989, Copley et al 2003, Pradillon et al 2005, organs for oocyte storage with spermathecae and thus internal fertilisation of oocytes (Zal et al 1994, Jollivet et al 2000, Hilario et al 2005. These species are also characterised by a high fecundity relative to their body size and produce mature oocytes of great size consistent with the hypothesis of lecithotrophic or direct development (McHugh & Tunnicliffe 1994, Zal et al 1995, Jollivet et al 2000.…”

“…They have focused either on families known from other marine environments (e.g. Ampharetidae, Polynoidae) (McHugh 1989, McHugh & Tunnicliffe 1994, Jollivet et al 2000 or on endemic families such as Alvinellidae or Siboglinidae (Zal et al 1995, Copley et al 1999, Thiébaut et al 2002, Pradillon et al 2005. They all showed peculiar adaptive convergence on reproductive mode and larval development.…”

“…However, its reproduction and recruitment dynamics remain poorly documented because of small sample sizes and sampling coverage, lack of temporal series of collections, and inability to keep animals alive after recovery on board. Recently, only 1 study showed different stages of female maturity within single local samples, therefore suggesting continuous gametogenesis at the scale of a local population (Pradillon et al 2005). Conversely, A. pompejana shows signs of the polymodal population structure associated with discontinuous recruitment that suggest the synchrony of individuals for at least 1 stage of the life cycle (Jollivet 1993).…”

Living in a hot redox soup: antioxidant defences of the hydrothermal worm Alvinella pompejana

“…In situ tem peratures recorded inside the tube of Alvinella are as high as 80°C, suggesting that the worm's habitat is flushed with high tem perature (Cary et al 1998, Di Meo-Savoie et al 2004, Le Bris et al 2005, Pradillon et al 2009. A. pom pejana is an active, highly aerobic worm (Jouin-Toulmond et al 1996, Hourdez et al 2000, Le Bris & Gaill 2007, but spends most of its time inside its tube, expanding its large gills only for very short periods (Desbruyères et al 1998, Pradillon et al 2005, Le Bris & Gaill 2007, probably to avoid the toxic effects related to potential ROS production from respiration in gills w hen ex posed to the hot hydrotherm al fluid outside the tube. The correlations betw een oxidative m etabolism and antioxidant activities have been previously investi gated in the alvinellid Paralvinella grasslei exposed to varying oxygen concentration in hyperbaric cham bers (Marie et al 2006).…”