Odontocheila cajennensis (Fabricius, 1787)

Odontocheila cajennensis View in CoL species-complex

(modified and shortened from Moravec 2018)

Identification. Species of his species-complex are characterized by yellow-testaceous metatibiae and mostly also metatarsi (except for O. oseryi which has the metatarsi partly or entirely metallic black, and O. parafemoralis sp. nov., which has last three metatarsi blackened). Some of the species have their abdomen testaceous, and in some this coloration may cover also the metasternum. Eight species of the complex were previously considered subspecies of O. cajennensis by Horn (1896, 1905, 1910, 1915, 1922, 1923, 1926, 1936), Rivalier (1969) and many subsequent authors. Because of the tremendous mutual variability, the taxa were differently interpreted by individual authors. As indicated by Rivalier (1969) and widely discussed and demonstrated recently ( Moravec 2016, 2018), due to the extreme mutual variability among several taxa, the species-complex represents a taxonomically most difficult problem within this species-group and even after the complete revision ( Moravec 2018) some of the taxa are not clearly defined.

Notwithstanding, despite the variability throughout the species-complex, O. parafemoralis sp. nov. described below is immediately distinguished from all other species of the complex.

For detailed descriptions of all taxa including remarks on their variability see the revision of the genus ( Moravec (2018).

Distribution. The species-complex has a large distribution from the Atlantic shore of Venezuela including Trinidad, Guyana, Surinam and French Guiana. The species of the complex penetrate from these countries and Colombian, Ecuadorian, and Peruvian Amazonia to Brazil, some of them obviously spreading along the multiple tributaries of the Amazon River throughout the vast Amazon Basin. In Brazil they spread in the state of Amazonas (Teffé = Tefé = Ega) to Manaus and to the state of Pará including Rio Tapajóz, Obidos and its eastern coastal areas, Belém on the Pará River, as well as to the southernmost areas of the Amazon Basin to Mato Grosso and Bolivian Santa Cruz.

The revision ( Moravec 2018) disclosed that most of the species of the O. cajennensis species-complex have sympatric and partly also syntopic occurrences, which contradicts the subspecies status of most of them. Considering also the great overall biodiversity of the Amazon Basin, they are treated as separate species after the revision. The adaptation of obviously vicariant populations to different biotopes and environmental changes may result in allopatric, parapatric or sympatric speciation up to genetically distinct sister species.