@article {Swierts2013,
	title = {{Lock, stock and two different barrels: comparing the genetic composition of morphotypes of the indo-pacific sponge Xestospongia testudinaria.}},
	journal = {PloS one},
	volume = {8},
	number = {9},
	year = {2013},
	month = {jan},
	pages = {e74396},
	publisher = {Public Library of Science},
	abstract = {The giant barrel sponge Xestospongiatestudinaria is an ecologically important species that is widely distributed across the Indo-Pacific. Little is known, however, about the precise biogeographic distribution and the amount of morphological and genetic variation in this species. Here we provide the first detailed, fine-scaled (<200 km(2)) study of the morphological and genetic composition of X. testudinaria around Lembeh Island, Indonesia. Two mitochondrial (CO1 and ATP6 genes) and one nuclear (ATP synthase $\beta$ intron) DNA markers were used to assess genetic variation. We identified four distinct morphotypes of X. testudinaria around Lembeh Island. These morphotypes were genetically differentiated with both mitochondrial and nuclear markers. Our results indicate that giant barrel sponges around Lembeh Island, which were all morphologically identified as X. testudinaria, consist of at least two different lineages that appear to be reproductively isolated. The first lineage is represented by individuals with a digitate surface area, CO1 haplotype C5, and is most abundant around the harbor area of Bitung city. The second lineage is represented by individuals with a predominantly smooth surface area, CO1 haplotype C1 and can be found all around Lembeh Island, though to a lesser extent around the harbor of Bitung city. Our findings of two additional unique genetic lineages suggests the presence of an even broader species complex possibly containing more than two reproductively isolated species. The existence of X. testudinaria as a species complex is a surprising result given the size, abundance and conspicuousness of the sponge.},
	issn = {1932-6203},
	doi = {10.1371/journal.pone.0074396},
	url = {http://dx.plos.org/10.1371/journal.pone.0074396},
	author = {Swierts, Thomas and Peijnenburg, Katja T C A and de Leeuw, Christiaan and Cleary, Daniel F R and H{\"o}rnlein, Christine and Setiawan, Edwin and W{\"o}rheide, Gert and Erpenbeck, Dirk and de Voogd, Nicole J},
	editor = {Voolstra, Christian~R}
}
@article {Worheide2005,
	title = {{Low variation in partial cytochrome oxidase subunit I (COI) mitochondrial sequences in the coralline demosponge Astrosclera willeyana across the Indo-Pacific}},
	journal = {Marine Biology},
	volume = {148},
	number = {5},
	year = {2005},
	month = {nov},
	pages = {907{\textendash}912},
	issn = {0025-3162},
	doi = {10.1007/s00227-005-0134-y},
	url = {http://link.springer.com/10.1007/s00227-005-0134-y},
	author = {W{\"o}rheide, Gert}
}
@article {Worheide2008,
	title = {{Deep genetic divergences among Indo-Pacific populations of the coral reef sponge Leucetta chagosensis (Leucettidae): founder effects, vicariance, or both?}},
	journal = {BMC evolutionary biology},
	volume = {8},
	number = {1},
	year = {2008},
	month = {jan},
	pages = {24},
	abstract = {BACKGROUND: An increasing number of studies demonstrate that genetic differentiation and speciation in the sea occur over much smaller spatial scales than previously appreciated given the wide distribution range of many morphologically defined coral reef invertebrate species and the presumed dispersal-enhancing qualities of ocean currents. However, knowledge about the processes that lead to population divergence and speciation is often lacking despite being essential for the understanding, conservation, and management of marine biodiversity. Sponges, a highly diverse, ecologically and economically important reef-invertebrate taxon, exhibit spatial trends in the Indo-West Pacific that are not universally reflected in other marine phyla. So far, however, processes generating those unexpected patterns are not understood. RESULTS: We unraveled the phylogeographic structure of the widespread Indo-Pacific coral reef sponge Leucetta chagosensis across its known geographic range using two nuclear markers: the rDNA internal transcribed spacers (ITS 1\&2) and a fragment of the 28S gene, as well as the second intron of the ATP synthetase beta subunit-gene (ATPSb-iII). This enabled the detection of several deeply divergent clades congruent over both loci, one containing specimens from the Indian Ocean (Red Sea and Maldives), another one from the Philippines, and two other large and substructured NW Pacific and SW Pacific clades with an area of overlap in the Great Barrier Reef/Coral Sea. Reciprocally monophyletic populations were observed from the Philippines, Red Sea, Maldives, Japan, Samoa, and Polynesia, demonstrating long-standing isolation. Populations along the South Equatorial Current in the south-western Pacific showed isolation-by-distance effects. Overall, the results pointed towards stepping-stone dispersal with some putative long-distance exchange, consistent with expectations from low dispersal capabilities. CONCLUSION: We argue that both founder and vicariance events during the late Pliocene and Pleistocene were responsible to varying degrees for generating the deep phylogeographic structure. This structure was perpetuated largely as a result of the life history of L. chagosensis, resulting in high levels of regional isolation. Reciprocally monophyletic populations constitute putative sibling (cryptic) species, while population para- and polyphyly may indicate incipient speciation processes. The genetic diversity and biodiversity of tropical Indo-Pacific sponges appears to be substantially underestimated since the high level of genetic divergence is not necessarily manifested at the morphological level.},
	keywords = {Animals, Biological, DNA, Founder Effect, Genetic Drift, Genetic Variation, Introns, Introns: genetics, Models, Phylogeny, Porifera, Porifera: classification, Porifera: genetics, Ribosomal, Ribosomal Spacer, Ribosomal Spacer: chemistry, Ribosomal Spacer: genetics, Ribosomal: chemistry, Ribosomal: genetics, Sequence Analysis},
	issn = {1471-2148},
	doi = {10.1186/1471-2148-8-24},
	url = {http://www.biomedcentral.com/1471-2148/8/24},
	author = {W{\"o}rheide, Gert and Epp, Laura S and Macis, Luciana}
}
@article {Worheide2005a,
	title = {{Biodiversity, molecular ecology and phylogeography of marine sponges: patterns, implications and outlooks.}},
	journal = {Integrative and comparative biology},
	volume = {45},
	number = {2},
	year = {2005},
	month = {apr},
	pages = {377{\textendash}85},
	abstract = {Marine sponges are an ecologically important and highly diverse component of marine benthic communities, found in all the world{\textquoteright}s oceans, at all depths. Although their commercial potential and evolutionary importance is increasingly recognized, many pivotal aspects of their basic biology remain enigmatic. Knowledge of historical biogeographic affinities and biodiversity patterns is rudimentary, and there are still few data about genetic variation among sponge populations and spatial patterns of this variation. Biodiversity analyses of tropical Australasian sponges revealed spatial trends not universally reflected in the distributions of other marine phyla within the Indo-West Pacific region. At smaller spatial scales sponges frequently form heterogeneous, spatially patchy assemblages, with some empirical evidence suggesting that environmental variables such as light and/or turbidity strongly contribute to local distributions. There are no apparent latitudinal diversity gradients at larger spatial scales but stochastic processes, such as changing current patterns, the presence or absence of major carbonate platforms and historical biogeography, may determine modern day distributions. Studies on Caribbean oceanic reefs have revealed similar patterns, only weakly correlated with environmental factors. However, several questions remain where molecular approaches promise great potential, e.g., concerning connectivity and biogeographic relationships. Studies to date have helped to reveal that sponge populations are genetically highly structured and that historical processes might play an important role in determining such structure. Increasingly sophisticated molecular tools are now being applied, with results contributing significantly to a better understanding of poriferan microevolutionary processes and molecular ecology.},
	issn = {1540-7063},
	doi = {10.1093/icb/45.2.377},
	url = {http://icb.oxfordjournals.org/content/45/2/377},
	author = {W{\"o}rheide, Gert and Sol{\'e}-Cava, Antonio M and Hooper, John N A}
}
