Macrochaetus Perty, 1850

Luo, Yongting & Segers, Hendrik, 2013, On Pulchritia new genus, with a reappraisal of the genera of Trichotriidae (Rotifera, Monogononta), ZooKeys 342, pp. 1-12 : 7

Genus Macrochaetus Perty, 1850

Type species.

Macrochaetus subquadratus Perty, 1850.

Emended diagnosis.

Body, including head and foot, loricate; head retractable, foot not retractable, inserted on a large, relatively soft and broad anal segment covering an equally soft and relatively broad first foot pseudosegment, and a stiff, cylindrical terminal foot pseudosegment. Trunk lorica dorso-ventrally compressed, relatively wide, pustulated, circular or with angular corners in the anterior third, head and neck lorica plates with spinulets.

Discussion.

Most species of Macrochaetus are readily identified as belonging to this genus by the presence of long, conspicuous dorsal spines. However, three species of Macrochaetus ( Macrochaetus aspinus Segers & Sarma, 1993, Macrochaetus danneelae Koste & Shiel, 1983, and Macrochaetus paggiensae Koste, 2000) lack these dorsal spines and their presence can therefore not be confirmed as generally diagnostic for the genus. On the other hand, small lorica spinulets are present dorsally, ventrally and marginally on the trunk lorica, and on the lorica of the head and neck regions. In particular the spinulets on the head and neck lorica appear to be synapomorphic for the genus. The foot consist of a large, relatively soft anal segment covering a relatively poorly sclerotized first foot pseudosegment and a terminal cylindrical foot pseudosegment bearing two separate toes. There are 14 species in this genus, several of which are endemic to South America ( Segers 2007, Segers and De Smet 2008).