Review of the Fridericia species (Oligochaeta: Enchytraeidae) possessing two spermathecal diverticula and description of a new species

Abstract

A new Fridericia species (Fridericia lacii sp. nov.) is described. Including this new species the number of valid Fridericia species with two diverticula per spermatheca is 50. The present study provides an opportunity for the comparison and separation of Fridericia species on the basis of spermatheca and diverticulum characteristics. Nine tables summarize the two larger groups and five subgroups of species possessing bidiverticulate spermathecae. The new species is distinguished from all known valid congeners in this assemblage by the following combination of traits: (1) 4–7 mm long, 200–290 µm wide (in vivo) with 30–36 segments; (2) maximum four chaetae per bundle; (3) all pairs of pharyngeal glands with ventral lobes, the third is the largest with posterior projections; (4) only three pairs of preclitellar nephridia; (5) oesophageal appendages type a; (6) mucocytes type a, lenticytes small; (7) chylus cells in preclitellar segments; (8) clitellum girdle‐shaped, glands in transverse rows, between the bursal slits only granulocytes; bursal slit is longitudinal; (9) seminal vesicle small or absent; (10) sperm funnel one‐half as long as the body diameter, collar narrower than the funnel body; (11) subneural glands absent; (12) the ampulla of the spermatheca with two sessile (or with short stalks), spherical, thin‐walled diverticula, communication with the oesophagus separate, ectal duct about as long as body diameter, one floppy ectal gland at the orifice.

Keywords:

• Oligochaeta
• Enchytraeidae
• new Fridericia species
• determination tables

Acknowledgements

The author is grateful to Dr Valerie Standen (Department of Biological Sciences, University of Durham, UK) for correcting the English. This research was financed by the National Scientific Research Foundation (OTKA 49635). Some research equipment (microscope and digital camera) was also provided by the OTKA Foundation (M 27225 and M 045482).