Phaenocora aglobulata Houben and Artois

Houben, Albrecht M., Steenkiste, Niels Van & Artois, Tom J., 2014, Revision of Phaenocora Ehrenberg, 1836 (Rhabditophora, Typhloplanidae, Phaenocorinae) with the description of two new species, Zootaxa 3889 (3), pp. 301-354 : 329

Phaenocora aglobulata Houben and Artois sp. nov.

( Figs 1 D, 3A–D)

Holotype: A sagittally-sectioned specimen, Prairie Grove (Alabama, USA). Pond with diverse submersed vegetation ( SMNH Type-8671), 34°31’0.48”N; 87°30’4.68”W, 0 1 June 2009.

Paratypes: Two sagitally- and one horizontally-sectioned specimens, same collection data as holotype (HU nos 565–566). Specimen (HU no. 567) subadult.

Etymology: Name refers to the absence of the giant unicellular glands, which are typical in other members with a female genital system of the AGLOBULATA - type.

Diagnosis: Animals about 1 mm long with an overall green or pinkish colour. Body pigmentation pink, confined to the anterior body region. Eyes pink. Zoochlorellae present in some specimens. Male copulatory organ of the duplex-type IIA. Female genital system of the AGLOBULATA - type, with a long female genital canal, a small genito-bursal duct lined with smaller unicellular glands, a heavily-lobed intestinal bursa, and a burso-intestinal duct with a valvular complex at the end. Large unicellular glands absent.

Description: Animals about 1 mm long (measured on serial sections), body colour green or pinkish. Pink eyes, and pink pigmentation occurs in the anterior body part. Zoochlorellae are sometimes present.

The male copulatory organ ( Fig. 3 C) is of the duplex-type IIA. At its proximal side, its muscular diaphragm is lined with a protruded epithelium ( Fig. 3 C: pr) at the point where the proximal and the distal bulbi connect. The cirrus clearly consists of three parts: a proximal part lined with a pseudocuticula and surrounded by very strong longitudinal muscles and rather weak circular muscles, a median part lined with a frayed nucleated epithelium and surrounded by less strong longitudinal and circular muscle layers, and a distal part lined by a low, nucleated epithelium and surrounded by longitudinal and circular muscle layers, with the longitudinal muscle layer increasing in strength.

The female genital system ( Fig. 3 B) is of the AGLOBULATA - type. The burso-intestinal duct ( Fig. 3 B: dbi) is connected with the gut by a valvular apparatus ( Fig. 3 B: va), without sphincter. The intestinal bursa ( Fig. 3 B: bi) consists of several lobes. Both burso-intestinal duct and the intestinal bursa are lined with an irregular, thick, nucleated epithelium. The cell boundaries of this epithelium are not visible and nuclei are scarce. There is a small genito-bursal duct ( Fig. 3 B: dgb), which is lined with smaller unicellular glands (as described by Gilbert 1938b for P. adenticulata ; also Fig. 3 B: lg). The female genital canal receives many secretion strands, which enter through the muscular sheet. Their cell bodies are situated at the ventral side of the body somewhat rostrally from the gonopore ( Figs 3 B, C: gl4).

Figures

FIGURE 1. Photographs of live animals A, P. evelinae. B, P. foliacea from South Africa. C, P. foliacea from India. D, P. aglobulata sp. nov.. E – H, P. gilberti sp. nov.: E – F, pigmentation of the head. G, male copulatory organ. H, female genital canal.