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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

[ref. ID; 6421 (R.O. Brinkhurst, 1988)]

Family Haplotaxidae

The family cannot be defined by unique apomorphies. It may be characterized as microdrile oligochaetes with two pairs of testes, one or two pairs of ovaries with the second pair rather than the first being lost where reduction has occurred. The dorsal and ventral blood vessels are connected by long comissural vessels, often in each segment. The chaetae are single or paired, usually simple-pointed, rarely bifid or pectinate. The spermathecae lie in front of the gonadal segments. The gonoducts are simple but there may be glands around the pores.

Type genus

Haplotaxis Hoffmeister, 1843

Family Tiguassidae (ref. ID; 6421 original paper)

Apomorphy is the cylindrical gizzard in VI-VIII in a worm with an eversible pharynx and septal glands. The loss of posterior ovaries, reduction of anterior set of male organs, and presence of a proboscis are some of several microdile characters retained by this family. The decision to erect a family for this taxon was reached independently but simultaneously by B.G.M. Jamieson (St. Lucia, Australia; personal communication).