FIGURE 2 in Biology, morphology and taxonomy of a snail-feeding leech from North Carolina, USA, provisionally identified as Helobdella lineata (Verrill, 1874) (Glossiphoniidae): First evidence for extra-oral digestion in the Hirudinea

FIGURE 2. Two types of aquatic habitat in southern Tyrrell County contain snail leeches provisionally identified as Helobdella lineata with different respective pigment patterns, suggesting pigmentation in this species is an adaptation to surroundings rather than inherently taxonomic. A–C, Agricultural dike canal draining low farmland [35.719874–76.107744]. Virtually all leeches collected in this muddy canal have typical metameric white spots, described in the paper as pigment variant #1. D, Sandy shoreline of a swamp with typical lush vegetation and clear water [35.721466–76.10195]. All individuals at this site have longitudinal stripes (described herein as pigment variant #4), i.e., lacking metameric white spots. In spite of differences in pigmentation the two respective habitats are only 0.55 km apart. The canal (A–C) is location of the 12-year population study presented in this paper. Arrows, aluminium leech traps (roughly 14 x 23 cm).