Genus account
Pachytriton Boulenger, 1878
Salamanders of the genus Pachytriton have smooth skin, a slender body lacking a vertebral ridge and a tail that is compressed laterally to varying degrees. Skull long and narrow. Where the long maxillary bones approach the pterygoids, the elements form approximately straight lines. Fronto-squamosal arch is rarely complete and attenuate if formed. The frontal process of the premaxilla, which is both long and broad, separates the nasals. The hyobranchial apparatus of Pachytriton is unique with the stout, bony epibranchials flaring dorsolaterally and wrapping round the neck, and is highly specialized for aquatic "gape and suck" feeding (Özeti & Wake, 1969). Most specimens have 12 trunk vertebrae (Chan et al., 2001). Previously thought to be related to Euproctus (Calotriton) asper, sharing with that species anatomical adaptations to life in streaming water (Herre, 1933; Freytag, 1982), in molecular studies the genus Pachytriton is now grouped with Cynops and Paramesotriton, and considered monophyletic (Chan et al., 2001; Weisrock et al., 2006). Several undescribed species, that on the basis of morphological similarities probably belong to Pachytriton, have been reported (Thiesmeier & Hornberg, 1997; Scholz, 1998), and a revision of the genus is in order.
Pachytriton archospotus Shen, Shen & Mo, 2008
Pachytriton brevipes (Sauvage, 1876)
Pachytriton labiatus (Unterstein, 1930)
References
Chan, L.M., Zamudio, K.R. & Wake, D.B., (2001)."Relationships of the Salamandrid Genera Paramesotriton, Pachytriton, and Cynops Based on Mitochondrial DNA Sequences." Copeia, 2001: 997-1009.
Freytag, G.E., (1982)."Über morphologische Eigenheiten und die phyletische Stellung der ostasiatischen Wassermolchgattung Pachytriton Boulenger, 1878 (Amphibia: Caudata: Salamandridae)." Vert. hung. Budapest, 21: 117-129.
Herre, W., (1933)."Zur Anatomie und systematischen Stellung von Pachytriton brevipes Sauvage." Z. Anat. Entw. Gesch. Abt.I, 102: 511-524.
Özeti, N. & Wake, D.B., (1969)."The Morphology and Evolution of the Tongue and Associated Structures in Salamanders and Newts (Family Salamandridae)." Copeia, 1969, 91-123.
Scholtz, K.P., (1998)."Über eine rauhhautige Pachytriton-Art." Salamandra, 34: 375-380.
Thiesmeier, B. & Hornberg, C., (1997)."Paarung, Fortpflanzung und Larvalentwicklung von Pachytriton sp. (Pachytriton A) nebst Bemerkungen zur Taxonomie der Gattung." Salamandra, 33: 97-110.
Weisrock, D.W., Papenfuss, T.J., Macey, J.R., Litvinchuk, S.N., Polymeni, R., Ugurtas, I.H., Zhao, E., Jowkar, H. & Larson, A., (2006). "A Molecular Assessment of Phylogenetic Relationships and Lineage Accumulation Rates within the Family Salamandridae (Amphibia, Caudata)." Molecular Phylogenetics and Evolution, doi: 10.1016/j.ympev.2006.05.008.
Tuesday, October 28, 2008