Redwood of the reef: growth and age of the giant barrel sponge Xestospongia muta in the Florida Keys

Trait-mediated ecosystem impacts: how morphology and size affect pumping rates of the Caribbean giant barrel sponge

“…In this study, we investigated the pumping rates of the giant barrel sponge X. muta, a particularly dominant Caribbean coral reef sponge. X. muta is a large and long-lived species that can comprise up to 65% of the total sponge biomass on some reefs (McMurray et al 2008, Southwell et al 2008 and is the second most common sponge across the Caribbean on the basis of percentage cover (Loh & Pawlik 2014). Our objectives were to determine how sponge size and morphology influence sponge pumping rates, and to determine how pumping may vary over time and with environmental changes.…”

“…Following excurrent velocity measurements, sponge height, base circumference, osculum diameter, spongocoel depth and spongocoel base diameter were measured with a flexible plastic measuring tape and calipers. For size and morphology estimates, sponge and spongo coel volumes were approximated as a frustum of a cone, and areas of oscula and spongocoel bases were approximated as circles (McMurray et al 2008).…”

The largest sponge in the world?

“…Aside from these two specimens, we encountered no individuals of this non reef-building species as part of the expedition, during which we conducted a total of 18 ROV dives to depths ranging from 1096 to 4829 m. The finding of such an enormous and presumably old sponge inside the Papahānaumokuākea Marine National Monument underscores the need to protect this area using the highest conservation measures available. While not much is known about the lifespan of sponges, some massive Communicated by P. Martinez Arbizu species found in shallow waters (<30 m) are estimated to live for more than 2300 years (McMurray et al 2008). Finally, the finding of such a large organism as that reported here highlights the value of using deepdiving technologies in surveying the deepest parts of our oceans, which remain largely unexplored.…”

“…Several marine sponges are known to attain massive sizes, thereby providing key ecosystem services such as filtering large amounts of seawater, as well as providing important habitat to a myriad of invertebrate and microbial species (McMurray et al 2008;Kerksen et al 2014). The largest dimensions reported for any sponge were those of a colony of Aphrocallistes vastus Schulze, 1887, found in shallow waters (<25 m) off western Canada.…”

No evidence for food limitation of Caribbean reef sponges: Reply to Slattery & Lesser (2015)

“…Therefore, DOC must be considered in the energetic budget and scope for growth of sponges. Our long-term monitoring of Xestospongia muta across a gradient of increasing POC at 15, 20 and 30 m has provided no evidence of enhanced growth with greater depth (McMurray et al 2008(McMurray et al , 2010, which Slattery & Lesser suggest may be attributable to a trade-off between greater food availability and 'increased bleaching stress suffered by X. muta ' (p. 278) at the deepest site, citing our data on sponge bleaching (McMurray et al 2011). However, a key conclusion in our study was that bleaching is a 'cyclic response by the cyanobacteria symbionts of X. muta that has no negative effect on the host sponge' (McMurray et al 2011(McMurray et al , p. 2249.…”