@article {Derycke:2010kx,
	title = {Linking DNA sequences to morphology: cryptic diversity and population genetic structure in the marine nematode Thoracostoma trachygaster (Nematoda, Leptosomatidae)},
	journal = {Zoologica Scripta},
	volume = {39},
	year = {2010},
	pages = {276-289},
	publisher = {WILEY-BLACKWELL PUBLISHING, INC},
	address = {COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA},
	abstract = {Recent taxonomic and population genetic studies have revealed the presence of substantial cryptic diversity through sequence analysis of nematode morphospecies classified in different major clades. Correct interpretations of intra- and interspecific genetic variation require certainty about the conspecificity of the sequenced specimens, which in turn must depend on appropriate protocols with built-in verifiability procedures. In this study, we performed a population genetic study in the free-living marine nematode Thoracostoma trachygaster, a member of one of the earliest major clades to diverge in nematode phylogeny. We collected 367 nematodes from 11 populations located in the Californian Bight, all of which were video captured before DNA extraction to document and verify their individual morphology. Sequences for the cytochrome c oxidase subunit 1 (COI), D2D3 and 18S genes showed eight deeply divergent clades, and using a reverse taxonomy approach, six of these clades proved to be other morphospecies than T. trachygaster. Phylogenetic analyses of COI, internal transcribed spacer and D2D3 showed evidence for two sympatrically distributed cryptic species within the morphospecies T. trachygaster. Population genetic analyses of the most widespread cryptic species showed a moderate genetic structuring (Theta(ST) = 0.28), and 18\% of this genetic variation was caused by differences between populations north and south of Point Conception. Within the southern Californian Bight, some genetic differentiation could be attributed to differences between populations north and south of Malibu, supporting the idea of a barrier to gene flow near Los Angeles region. The results for T. trachygaster support the contention that species diversity within free-living nematodes is underestimated, and that dispersal of marine nematodes from tidal environments associated with kelp holdfasts is substantial at scales of a few 100 km.},
	doi = {DOI 10.1111/j.1463-6409.2009.00420.x},
	author = {Derycke, Sofie and De Ley, Paul and De Ley, Irma Tandingan and Holovachov, Oleksandr and Rigaux, Annelien and Moens, Tom}
}
@article {Holovachov:2008kx,
	title = {Nematodes from the Gulf of California. Part 2. Ceramonema nasobema sp n. (Nematoda: Ceramonematidae)},
	journal = {Nematology},
	volume = {10},
	year = {2008},
	pages = {835-844},
	publisher = {BRILL ACADEMIC PUBLISHERS},
	address = {PLANTIJNSTRAAT 2, P O BOX 9000, 2300 PA LEIDEN, NETHERLANDS},
	abstract = {An unusual new ceramonematid, Ceramonema nasobema sp. n., is described using light and scanning electron microscopy. It is particularly characterised by the presence of a perioral tube projecting 5.5-7.0 mu m anterior to the lips, moderately long body (0.86-1.09 mm), relatively small number of body annules (121-134), weakly developed zygapophyses, absence of intracuticular vacuoles, pronounced sexual dimorphism in amphid shape with the male ventral amphidial branch extending as far posterior as the 55-80th annule (no extension in females), barrel-shaped stoma, sigmoid and anteriorly inclined vagina without sclerotisations, gubernaculum with dorsal apophyses and relatively uniform cloacal annules. The new species differs from all other known species of Ceramonema especially by the shape of the amphid in males, the strongly projecting perioral tube and the inclined, sigmoid, vagina. Additional data on morphology of Ceramonema algoensis (from Natal Bay, South Africa) are also provided as this species has the most prominent perioral tube among previously described members of the genus.},
	keywords = {Baja California, Ceramonema algoensis, Mexico, morphology, morphometrics, SEM, taxonomy},
	author = {Holovachov, Oleksandr and Mundo-Ocampo, Manuel and De Ley, Irma Tandingan and De Ley, Paul}
}
