Alboglossiphonia pallida (Verrill, 1872) Moser & Richardson & Hammond & Rojas & Lazo-Wasem & Phillips, 2022

Moser, William E., Richardson, Dennis J., Hammond, Charlotte I., Rojas, Lourdes, Lazo-Wasem, Eric & Phillips, Anna J., 2022, Resurrection and redescription of Clepsine pallida Verrill, 1872 (Hirudinida, Glossiphoniidae) with a phylogeny of the genus Alboglossiphonia, ZooKeys 1127, pp. 135-154 : 135

Alboglossiphonia pallida (Verrill, 1872) comb. nov.

Figs 2 , 3 , 4 , 5

Diagnosis.

Dark chromatophores on the dorsal surface arranged lateral to patrilaterally and medially as a thin line or interrupted thin line along with three pair of eye spots (where the first pair are closest together), six pair of crop ceca, and a united gonopore.

External morphology.

Body narrowly ovoid to narrowly pyriform. Rounded anterior region. Dorsum buff to translucent, smooth (without papillae), and with small, black chromatophores that form thin lines with scattered areas; thin, interrupted mid-dorsal line with larger chromatophore patches (typically on sensory annuli); black chromatophores in a lateral pattern on the sensory annulus of the lateral to paralateral region (Figs 2 , 3 ). Three pair of eye spots which are typically separate and arranged linearly or with groupings of two and four eye spots in unpigmented cephalic area with the first pair of eye spots closest together (Figs 3 , 4 ). Some individuals have five eye spots where the first pair is present and there are only three eye spots in the second and third pair. Caudal sucker of moderate size (half diameter of mid-body) without pigment or papillae. Ventrum without pigment or papillae and with united male and female gonopores (single opening) (Fig. 2 ).

Alimentary tract.

Cylindrical, blunt-tipped protrusible proboscis (approximate length of 14 annuli), opening at the center of the oral sucker. Short esophagus and diffuse salivary glands that are distributed in the anterior third of the body (Fig. 5 ). Crop with six pair of ceca and last pair extend posteriad and diverticulated with four sections; four pair of simple, saccular intestinal ceca with hind gut saccate and rectum opening into anus, located one annulus anteriad of the caudal sucker (Fig. 5 ).

Reproductive anatomy.

Male atrium opening into paired narrowly ovoid atrial cornua that extends laterally and narrows abruptly at junction with ejaculatory ducts and extends posteriad (Fig. 5 ). Six pair of testisacs between crop ceca. Pair of tubular ovisacs; length of ovisacs dependent on the reproductive state of the leech (Fig. 5 ). Male and female gonopores united.

Figures

Figure 2. Holotype specimen of Clepsine pallida Verrill, 1872 (YPM IZ 000253) A dorsal surface B ventral surface. Scale bar: 1 mm.

Figure 3. Living specimen of Alboglossiphonia pallida (Verrill, 1872) from the type locality of New Haven County, Connecticut, USA. YPM IZ 106029, dorsal surface Scale bar: 1 mm.

Figure 4. Images of the arrangement of eyespots of Alboglossiphonia pallida (Verrill, 1872) A YPM IZ 106029 B USNM 1662161 C YPM IZ 062698 D YPM IZ 107064.

Figure 5. Schematic drawing of the internal morphology of Alboglossiphonia pallida (Verrill, 1872). Abbreviations: AC, atrial cornuae; CC, crop ceca; HG, hind gut; IC, intestinal ceca; O, ovisac; PR, proboscis; SC, salivary cells; T, testisac.