Polychaete fauna inhabiting sediments associated with the stinking vase sponge (Ircinia campana Lamarck, 1814), St. John, United States Virgin Islands

Abstract

As part of a general polychaete survey of St. John, United States Virgin Islands, an analysis was conducted on macrofaunal polychaete assemblages found in sediments trapped within the stinking vase sponge (Iricinia campana Lamarck, 1814) growing in shallow water at less than 4 m depth. Higher species numbers and greater abundances were found within the sponges than in adjacent sand. Polychaetes comprised over 90% of all macrofauna found in the two habitats, with 41 species within 21 families: Acoetidae, Amphinomidae, Capitellidae, Chrysopetalidae, Cirratulidae, Dorvilleidae, Eunicidae, Euphrosinidae, Glyceridae, Hesionidae, Maldanidae, Nereididae, Oenonidae, Orbiniidae, Opheliidae, Sabellidae, Sigalionidae, Spionidae, Syllidae, Terebellidae, and Trichobranchidae. Univariate statistics, community ordination (nonmetric multidimensional scaling) and a multiple response permutation procedure revealed differences in assemblage compositions between vase sponge sediments and open sand. Seven polychaete species found in vase sponges were not found in any other habitats in the survey area. Vase sponges appear to be population refugia for many soft-bottom polychaete species scarcely found or absent in adjacent reef habitats, by supplying protection from predators and currents, finer and more organically enriched sediments within the concavities, and food derived from the sponges.

<p class="ZootaxaTitle"><strong>Nocturnally swarming Caribbean polychaetes of St. John, U.S. Virgin Islands, USA</strong></p>

“…The ubiquitous opheliid Polyophthalmus pictus frequently swarmed, yet there was no evidence of gametes in these animals even when dissected, and the swarmers looked identical to non-swarming forms found in benthic samples (Prentiss & Harris 2011). These Polyophthalmus swarmers may have been atokes that were attracted to the lights, but possibly they were male epitokes that had already shed their sperm.…”

“…In Great Lameshur Bay, the benthic environment in the immediate vicinity of the collecting site (NPS dock), may not have provided suitable habitat for epitoke-forming eunicids. Yet some eunicid species are common in Great Lameshur Bay, where the species Eunice vittata (Dell Chiaje, 1828) and Lysidice unicornis (Grube, 1840) were collected from benthic vase sponges and coarse sand (Prentiss & Harris 2011). The author also collected many specimens of the "Atlantic Palola worm" (Eunice fucata Ehlers, 1887) from dead coral rubble and benthic fouling matter near the Great Lameshur Bay NPS dock.…”

“…The epitokes of some glycerids can be difficult to identify since epigamous metamorphosis may cause an atrophy or degeneration of the proboscis and associated jaws (Simpson 1962;Pettibone 1963). Glycera was collected from benthic substrates in Great Lameshur Bay (Prentiss & Harris 2011), however no epitokous glycerids were ever collected in nocturnal plankton samples. The goniadid epitokes collected in this study also appeared on several nights around the full moon phase.…”

Cryptic biodiversity inhabiting coral reef sponges

“…The current study focussed on three Great Barrier Reef sponge species representing genera largely unexplored in comparison to other studies, e.g. Verongia (Voultsiadou‐Koukoura et al, 1987), Agelas , Aplysina , Axinella (Koukouras et al, 1996), Haliclona (Abdo, 2007; Skilleter et al, 2005) with the exception of Ircinia campana (Prentiss & Harris, 2011) where research focussed on endofauna groups of only ophiuroids (Dahihande & Thakur, 2017; Hendler, 1984; Henkel & Pawlik, 2005, 2014) and polychaetes (Neves & Omena, 2003; Pola et al, 2020b; Prentiss & Harris, 2011). The present study yielded an abundance of 8489 SAB with molluscs dominating all the three sponge hosts: 52.5% ( I .…”

“…Sponges provide these SAB shelter from predators and nutrition via the movement of plankton and organic material (Arndt, 1933; Konstantinou et al, 2018). Consequently, descriptive accounts of the biodiversity associated with sponges have shown a remarkable range of taxa such as, cyanobacteria (Konstantinou et al, 2018; Pagliara et al, 2020; Usher et al, 2006), cnidarians (Sanamyan et al, 2012), zooanthids (Swain, 2012), polychaetes (Dauer, 1973; Gherardi et al, 2001; Martin & Britayev, 1998; Nalesso et al, 1995; Neves & Omena, 2003; Pola et al, 2020b; Prentiss & Harris, 2011), cyclopoid copepods (Çinar et al, 2002), amphipods (Costello & Myers, 1987; Poore et al, 2000; Myers & George, 2017; White & Thomas, 2009), isopods (Lörz & Bruce, 2008), mysids, decapod crustaceans (Duffy, 1996), molluscs (gastropods, nudibranchs, bivalves; Kohn, 1983; Proksch, 1994), bryozoans (Almeida et al, 2017; Ehlers, 1876; Harmelin et al, 1994; Morgado & Tanaka, 2001), barnacles (Hosie, Fromont, Munyard, & Jones, 2021; Hosie, Fromont, Munyard, Wilson, & Jones, 2021; Ilan et al, 1999), brittle stars (Dahihande & Thakur, 2017; Hendler, 1984; Hendler et al, 1999; Henkel & Pawlik, 2005, 2014), tunicates (Fiore & Jutte, 2010) and fishes (Randall & Lobel, 2009; Tyler & Böhlke, 1972). The range of taxa found within sponges highlights the importance of sponges as habitat reservoirs and, more broadly, their contributing ecological roles on reefs (Koukouras et al, 1996; Wendt et al, 1985), and deeper marine habitats (Pham et al, 2019).…”