Topic
Nucula
About: Nucula is a research topic. Over the lifetime, 37 publications have been published within this topic receiving 1175 citations.
Papers
TL;DR: The results indicate that hawksbills can have a positive indirect effect on corals by grazing on coral competitors, as well as affect overall reef benthic biodiversity, and challenges the prevailing view that Caribbean hawksBills are strict spongivores.
Abstract: We evaluated selective feeding in hawksbill turtles Eretmochelys imbricata by compar- ing ingested prey species with their availability at 2 sites in the SW Dominican Republic. Hawksbills fed on 6 benthic species: 5 demosponges (Chondrilla nucula, Geodia neptuni, Myriastra kalitetilla, Spirastrella coccinea, and Tethya crypta) and 1 corallimorpharian (Ricordea florida). Hawksbills showed positive selection for 4 species (from highest to lowest): S. coccinea, R. florida, and C. nucula at Bahia de las Aguilas, and M. kalitetilla and C. nucula at Cabo Rojo. S. coccinea and M. kalitetilla are rare in the environment and highly selected by hawksbills, which supports a previous observa- tion that their distribution on reefs could be greatly affected by spongivores. The 2 remaining selected species were the dominant prey species in lavage samples (R. florida = 59% and C. nucula = 34% of total volume). Since they were the most abundant species at each site, this illustrates that diet choice is based on a combination of selectivity for certain species and local abundance. The domi- nance of R. florida in the diet challenges the prevailing view that Caribbean hawksbills are strict spongivores. Finally, our results indicate that hawksbills can have a positive indirect effect on corals by grazing on coral competitors, as well as affect overall reef benthic biodiversity. Both C. nucula and R. florida harbor photosynthesizing symbionts and are aggressive competitors for space on tropical reefs. Thus, at natural population levels, grazing by hawksbills may well have played an important role in Caribbean reef structure and dynamics. Because hawksbill populations have been substan- tially reduced (to at most 10% of pre-Columbian population levels) their effect has been considerably diminished.
246 citations
TL;DR: The results reject the null hypothesis of cosmopolitanism of C. nucula and indicate that the putative worldwide distribution of some marine sponges, and possibly many other benthic invertebrates, may be the result of overly conservative systematics.
Abstract: The sponge species Chondrilla nucula has a simple morphology and a very wide geographical distribution. To verify whether the latter might be an artifact of the former, samples of this species were collected across 10,000 km of its range, in the Mediterranean, the Caribbean, and the southwestern atlantic. The classical (spicule morphology) and molecular (allozymes) systematic approaches were compared, to try to define the geographic limits between populations and detect possible cryptic species. We found five distinct genetic forms within C. nucula that sometimes showed morphological homogeneity and other times plasticity. The difference in size of spicules could not be related to the clear-cut genetic differences, suggesting that the use of spicule sizes for sponge systematics should be reappraised. The population of one of the genetic forms along 3000 km of the Brazilian coast was highly structured (FST = 0.21; Ne m = 0.96). Our results reject the null hypothesis of cosmopolitanism of C. nucula and indicate that the putative worldwide distribution of some marine sponges, and possibly many other benthic invertebrates, may be the result of overly conservative systematics. Cryptic species appear to be particularly prevalent when genera are well defined but species are characterized by only a few morphological characters.
218 citations
TL;DR: Experiments examining clearance and retention rates of the bacterium Escherichia coli found that C. nucula exhibited a marked ability to retain high quantities of bacteria, suggesting that this sponge is a suitable species for marine environmental bioremediation.
118 citations
TL;DR: Experiments were performed to measure ingestion rate and selectivity of inorganic, organic and microbial fractions, and absorption efficiency of ingested microbes by Nucula annulata and Hydrobia totteni offered silt-clay sediments.
Abstract: Three of the most important aspects of deposit-feeding behaviour are ingestion rate, ingestion selectivity and absorption efficiency of ingested food. The purpose of the experimental results described here is to allow estimation of these traits for animals offered natural sediments. Experiments were performed to measure ingestion rate and selectivity of inorganic, organic and microbial fractions, and absorption efficiency of ingested microbes by Nucula annulata (Bivalvia) and Hydrobia totteni (Gastropoda) offered silt-clay sediments. N. annulata selectively ingested the organicand bacteria-rich sediment fraction, and absorbed bactena with 72 % efficiency. H. totteni ingested the sediment non-selectively, and absorbed sediment-associated bacteria and algae with approximately 40 % efficiency.
74 citations
TL;DR: The survey of the sublittoral fauna of the Clyde Sea Area from 1949 onwards has shown that five species of the Protobranchiata are abundant throughout this region on a variety of substrata.
Abstract: The survey of the sublittoral fauna of the Clyde Sea Area from 1949 onwards has shown that five species of the Protobranchiata are abundant throughout this region on a variety of substrata. Pelseneer (1891, 1899, 1911), Heath (1937), and Yonge (1939) have contributed much to the knowledge of the group as a whole, but little comparative work has been done at species level. Verrill & Bush (1897, 1898) studied the shell characters of the American Atlantic species. Moore (1931 a, b) worked on the faecal pellets of the British Nuculidae and attempted to distinguish the species by this means, while Winckworth (1930,1931), mainly in the light of the latter work, attempted to clarify the nomenclature of these species. Winckworth (1932) lists six British species of the family Nuculidae: Nucula sulcata Bronn, N. nucleus (Linne), N. hanleyi Winckworth, N. turgida Leckenby & Marshall, N. moorei Winckworth and N. tenuis (Montagu); and four species of the family Nuculanidae: Nuculana minuta (Muller), Yoldiella lucida (Loven), Y. tomlini Winckworth and Phaseolus pusillus (Jeffreys). All species of Nucula, except N. hanleyi, were taken from the Clyde Sea Area, although the latter species is included in the Clyde fauna list (Scott Elliot, Laurie & Murdoch, 1901). Only Nuculana minuta of the Nuculanidae has been taken on the present survey. Yoldiella tomlini is included in the 1901 list but is noted as being ‘insufficiently attested’. Nucula hanleyi was obtained from the Marine Station, Port Erin, but Yoldiella and Phaseolus were unobtainable.
41 citations
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Performance Metrics
| Year | Papers |
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| 2013 | 1 |
| 2012 | 1 |
| 2011 | 1 |
| 2009 | 1 |
| 2008 | 2 |
| 2007 | 2 |