Seasonality and zonation in the reproductive biology and population structure of the shrimp Alvinocaris stactophila (Caridea: Alvinocarididae) at a Louisiana Slope cold seep

Abstract

Ecological patterns in deep-sea chemosynthetic environments are often considered to be independent of variations in photosynthetic primary production. This study examined spatial and temporal variation in the reproductive development and population structure of the caridean shrimp Alvinocaris stactophila at the Brine Pool cold seep on the Louisiana Slope. To assess spatial variation, samples were collected by submersible from different locations across the Brine Pool mussel bed in November 2003. The proportion of males in samples declined from the outer to the inner zone of the mussel bed, while the proportion of female shrimp carrying eggs increased. This zonation may have resulted from the congregation of large ovigerous females towards the inner zone, where sulphide flux from underlying sediments may be absent or reduced. To examine temporal variation in reproductive development, oocyte size-frequency distributions were compared between August 1997, March 2002, February 2003, November 2003, and July 2004. All oocytes in early spring samples were small and previtellogenic, while summer samples contained larger vitellogenic oocytes. The largest oocytes were found in large non-ovigerous females from the autumn, whereas ovigerous females from the same season contained the smallest oocytes observed in this study. Embryos in the autumn exhibited no differentiation, in contrast to well-developed embryos from early spring that hatched into zoea larvae. These features indicated seasonal and iteroparous reproduction in A. stactophila, with females carrying embryos from autumn to early spring, possibly timing the release of planktotrophic larvae to exploit a seasonal peak in surface productivity and its export.

Reproductive aspects of two bythograeid crab species from hydrothermal vents in the Pacific-Antarctic Ridge

“…However, species with planktotrophic larvae that disperse away from the chemosynthetic environment might still exhibit seasonal reproductive patterns. Seasonal reproduction at vents and seeps has been documented in bivalves (Le Pennec & Beninger 1997, Lisin et al 1997, Dixon et al 2006, Tyler et al 2007) and decapods (Perovich et al 2003, Copley & Young 2006). In the case of Bythograea thermydron, hatching of planktotrophic larvae coincides with the seasonal (spring and summer) phytoplankton blooms in surface waters (Perovich et al 2003).…”

Genetic population structure of four hydrothermal vent shrimp species (Alvinocarididae) in the Okinawa Trough, Northwest Pacific

“…All known larvae of alvinocaridid shrimp are planktotrophic, which enable them to disperse over long distances (e.g. Ramirez-Llodra et al 2000, Copley & Young 2006, Ramirez-Llodra & Segonzac 2006, Nye et al 2013, whereas neoverrucid larvae are lecithotrophic (Watanabe et al 2004). Under atmospheric pressure, the survival rate of neoverrucid larvae drastically decreases at temperatures >15°C, which corresponds to temperatures above the sill of the Ryukyu Arc (Watanabe et al 2005).…”

Assessment of decadal-scale ecological change at a deep Mid-Atlantic hydrothermal vent and reproductive time-series in the shrimp Rimicaris exoculata

“…Oocyte sizefrequency distributions of female shrimp in a September sample from TAG and a July sample from the Rainbow hydrothermal vent field do not indicate seasonal synchrony of development (Ramirez Llodra et al, 2000), but oocyte development has yet to be examined in samples from TAG in other months or seasons for comparison. Such comparison has identified seasonal reproduction in another Alvinocaridid species at a cold seep, where ovigerous females were also absent from summer samples (Copley & Young, 2006).…”

“…Other crustaceans appear to avoid the sulphidic extremes of chemosynthetic environments while brooding embryos (Copley & Young, 2006). It is therefore possible that ovigerous R. exoculata leave the aggregations around high-temperature vents where samples are generally collected (Ramirez Llodra et al, 2000).…”

“…The scarcity of ovigerous R. exoculata noted in summer samples (Gebruk et al, 1997;Ramirez Llodra et al, 2000) also persists in the November sample examined here and may result from a spatial pattern rather than a temporal one. Other crustaceans appear to avoid the sulphidic extremes of chemosynthetic environments while brooding embryos (Copley & Young, 2006). It is therefore possible that ovigerous R. exoculata leave the aggregations around high-temperature vents where samples are generally collected (Ramirez Llodra et al, 2000).…”