Globulidrilus, Christensen & Dózsa-Farkas, 2012

Christensen, Bent & Dózsa-Farkas, Klára, 2012, A new genus Globulidrilus and three new enchytraeid species (Oligochaeta: Enchytraeidae) from Seoraksan National Park (Korea), Journal of Natural History 46 (45 - 46), pp. 2769-2785 : 2770-2771

Globulidrilus gen. nov.

Type species

Globulidrilus helgei sp. nov. (see later)

Diagnosis

Chaetae sigmoid, without nodulus. Lateral bundles shifted dorsally. Head pore at 0/I. Brain deeply incised posteriorly, convex in front. Ventral nerve cord medullar. Oesophageal appendages (peptonephridia) absent. Pharyngeal glands with large ventral lobes. No intestinal diverticula, transition from oesophagus to intestine gradual. Segmental dorsal pores absent. Postclitellar origin of dorsal blood vessel, blood reddish. Anterior bifurcation of dorsal blood vessel in I. Nephridium with a small anteseptale containing few coils of the nephridial canal, postseptale elongate with the ectally leading canal arising anteriorly near the septum while what appears as the efferent duct remains attached to the ventral side of the postseptale until sub-terminally. Coelomocytes of one type (mucocytes) only. Spermatheca with a thin-walled ampulla where the sperm is arranged in regular bundles at its basis and occupying only a minor part of the lumen. Ampulla usually attached to oesophagus by a fine strand of tissue but apparently without any open connection.

Etymology

“Worms carrying a globe”, referring to the characteristic spermathecal ampulla resembling a lottery bowl and the sperm bundles the numbered balls.

Included species

Globulidrilus helgei sp. nov.; Globulidrilus riparius ( Bretscher, 1899)

Distribution and ecology

Members of the genus widely distributed in the Eurasian region mostly occupying wet habitats.

Remarks

In some characters often used to characterize genera of Enchytraeidae , such as shape of chaetae, origin of the dorsal vessel and absence of oesophageal and intestinal diverticula, Globulidrilus resembles the genera Cognettia and Lumbricillus but other distinctive features are apparent from Table 1. The two most distinguishing characters are:

(1) Spermathecal ampulla thin-walled, fairly large, with sperm arranged in regular bundles at its basis; ampulla usually attached to the oesophagus by a fine strand of tissue but without open connection.

(2) Nephridia with a small anteseptale, the ectally leading canal of the postseptale arising anteriorly near the septum, remaining attached to ventral side of postseptale until sub-terminally.