The Manner in Which the Sponge Cliona Bores in Calcareous Objects

Abstract

Boring in shells and calcite crystals was investigated, sing a new type of reconstitution culture. No free acid was detected, and no detectable q~lantity of calcium \\,as p~~t in solution by the sponge. However, acid action is indicated by restriction of boring to c a l c i~~~n carbonatc. Conchiolin is penetrated with difficulty. Cells in contact with the substratunl form a reticululn of fine pseu?opodia and lilamellts; a correspondi~ig pattern of lines is etched into the calclte. 'I'he areas so markcd out are the same size and shape as the fragments discharged by the sponge. These fragments arc identical \vliether from shells or calcitc crystals; their faces are curved but their edges sharp. Apparently the cytoplasmic filaments insinuate the~nselves into calcite by secreting minute alnounts of acid, and undercut fragrnellts which are carried through the sponge parenchyma to excurrent canals.Cliona is a cosmopolitail genus of nlarine siliceous spoilges (F. Clionidae, 0. Haclromerina, C1. Demospongiae), remarltable for the habit of living in tu!lnels and galleries bored in limestone, coral, ancl the shells of n~olluscs. The damage inflicted by Cliona on various mollusc fisheries and on limestone brealrwaters invests the genus with some economic importance, and spongeriddled shells ancl stones are familiar objects to the naturalist on the seashore. The manner in which the galleries are excavated has therefore attracted the researches of several biologists, and the speculations of many more. This paper will recount some of the results of an investigation into the biology of boring sponpes, sponsored by the Fisheries Research Board of Canada because of the deleterious eRects of the sponges on the oyster and scallop fisheries of eastern Canada. The work was carried out a t the Board's Biological Sub-station, situated on Malpeque Bay on the north shore of Prince Edwarcl Island, near Ellerslie. Studies were largely confined to Cliona celata, the prevalent species in that area. Historical NoteGrant (3), who first described Cliona celata, believed that his new "zoophyte" dwelt in burrows made by worms. Bowerbank (1) shared this opinion. Hancoclr (4,s) refuted Bowerbanlr's arguments, and made it clear that Cliona bored its o~v n holes; he suggested that this was done by grinding with the spicules. However, Nassanov (9,lO) showed that Cliona larvae began to bore before they possessed spicules.Nassanov had described the fragments of shell discharged by boring sponges. These, and fragments of conchiolin from bored oyster shells, were figured by Topsent (12), who pointed out that since coilchiolin is bored in the 'Manuscript

Effects of ocean acidification and global warming on reef bioerosion—lessons from a clionaid sponge

“…We argue that the strong variation in the contribution of chemical dissolution may partly be influenced by the pH of the surrounding water, considering that according to Doney (2006), the 2 sites with the experi mentally determined highest ratios of chemical bioerosion -the Red Sea and the Mexican Pacific (Zundelevich et al 2007, Nava & Carballo 2008) -have comparatively acidic seawater (ca. pH 7.9 according to Doney 2006), while the classic studies with low ratios of chemical bioerosion were conducted in less acidic areas (Warburton 1958, Rützler & Rieger 1973; around pH 8.1 according to Doney 2006). This theory may be supported by observations by Schönberg (2008), who noticed significant differences in sponge scar morphologies comparing the width of the groove etched to remove the sponge chips.…”

“…Compared to our value of 9% chemical bioerosion in Cliona orientalis, a considerable range of ratios between contributions of chemical and mechanical sponge bioerosion have been reported in the literature. Warburton (1958) estimated that <10% of carbonate is dissolved by Cliona cf. celata from Eastern Canada.…”

The role of burrowing sponges in bioerosion

“…From this data he calculated that. CliQna infested substrata can lose 8S much as 1.4 cm per year, or 6-7 kg per m 2 per 100 days, producing nearly 6 kg fine sediments per m 2 per 100 days (assuming 10% removal in solution, as proposed by Warburton, 1958).…”

Are oysters being bored to death? Influence of Cliona celata on Crassostrea virginica condition, growth and survival

“…Numerous studies have examined clionid infestation rates and burrowing activities in oyster shells (Warburton 1958c, Alagarswami & Chellam 1978, Thomas 1979, Wesche et al 1997, Carver et al 2010, Daume et al 2010, although surprisingly few have considered the impacts on oyster condition and growth rates (but see Schleyer 1991, Rosell et al 1999. In temperate regions of the USA Cliona celata is the dominant excavating sponge on oyster reefs (Hartman 1958).…”