Wednesday, October 26, 2016

Two new wrasses: Cirrhilabrus rubeus and Cirrhilabrus africanus

Cirrhilabrus rubeus
The fish family of the wrasses or Labridae is a particular large group of marine fishes. It contains over 600 species of mostly smaller (<20cm) and often colourful fish that are associated with coral reefs or rocky shores. Juveniles of some species hide among the tentacles of mushroom coral.

Wrasses are carnivores, feeding on a wide range of small invertebrates. Many smaller species follow the feeding trails of larger fish, picking up invertebrates disturbed by their passing. A lot of labrid species are common in both public and home aquaria.

Cirrhilabrus africanus
Two new species have been described by a colleague of many years. Both new species are from the Indian Ocean, one (C. rubeus) from Sri Lanka and the Maldives, the other from the east African coast (C. africanus). The first species was named for its bright red color and the second for its origin.

For the experts: The western and central Indian Ocean population of the fairy wrasse, Cirrhilabrus rubriventralis, is here split into three allopatric species: the type species from the Red Sea; C. rubeus, n. sp., a new central Indian Ocean species from Sri Lanka and the Maldives; and C. africanus n. sp., a new east African coastal species. The three species are mainly differentiated by the color patterns of terminal-phase (TP) males. The two new species diverge from C. rubriventralis in the sequence of the barcode-mtDNA COI marker by 2.6% and 0.5%, respectively (pairwise distance; 2.7% and 0.5% K2P distance). The Indian Ocean species complex made up of the 8 spike-fin species allied with C. rubriventralis is now one of the larger species complexes among labrid reef fishes, showing an interesting pattern of allopatric sibling species dividing up the region, as well as the occurrence of localized microendemic species in Indonesia and the Timor Sea. The species complex includes some species that share mtDNA lineages (phenovariant species), as well as others up to 2.9% divergent in sequence. A neighbor-joining tree and genetic distance matrix is presented for 7 of the 8 known species in the complex. 

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