Haemopis septagon Sawyer & Shelley, 1976

Sawyer, Roy T., 2019, Observations on the terrestrial leech Haemopis septagon Sawyer & Shelley, 1976 (Annelida: Hirudinea) from the Outer Banks, North Carolina, USA, with a revision of the species, Zootaxa 4658 (2), pp. 275-296 : 292

Haemopis septagon Sawyer & Shelley, 1976 . Revised

Synonymy:

Haemopis septagon Sawyer & Shelley, 1976 ; Shelley 1977; Shelley et al. 1979.

Haemopis ottorum Wirchansky & Shain, 2010 .

Diagnosis. Eyes 5 pairs in characteristic hirudinid arc; 16 complete (5-annulate) segments (IX–XXIV); male and female gonopores separated by 6 ½ to 7 annuli, typically at XIb5/b6 and XIIIb1/b2; typically 14–16 distichodont teeth per jaw; known from mid-Atlantic coastal plain, from South Carolina to southern New Jersey ( Fig. 10 ).

Description. Terrestrial, semi-terrestrial or amphibious; predaceous on oligochaetes; length of adults up to at least 150 mm; pigmentation concolor with no metameric patterns, basically olive green in life, with or without irregular black specks dorsally (and sometimes ventrally); jaws low and rounded; at least one pharyngeal ridge terminating between each jaw; lengthy pharynx, extending to ganglion XI; adult crop basically a long irregular tube without bilateral caeca, except a pair of posterior caeca extending from segment XIX to XXIV ( NOTE: In juvenile specimens there are two sets of distinguishable crop caeca per segment, not evident in adults) (see Fig. 8 ); intestine comprised of two parts (see Fig. 4 ); ejaculatory bulb and epididymis well developed; ejaculatory ducts lengthy and tortuous; small vaginal caecum, even in juveniles; segments VII, 3-annulate; VIII, 4-annulate; the two adjacent annuli VIIa3 and VIIIa1 characteristically broadened; XXIV, 5-annulate; XXV, 3-annulate; female gonopore sometimes with a nipple-like protuberance, commonplace in adults but not juveniles; penis sometimes everted externally; male opening penetrates ventral body wall behind ganglion XI and the female opening penetrates immediately anterior to ganglion XIII; prostate located in segment XII and the ovisacs at ganglion XIII; penis sheath and vaginal stalk increasingly long and coiled as animal matures, with flexion from ganglion XIII 1/ 2 in juveniles to as far as ganglion XVI in mature adults; epididymis extending well beyond ejaculatory bulb in mature adults (much smaller in juveniles); 11 (10–12) pairs of testisacs, in segments XIII to XXIII, inclusively.

Figures

FIGURE 4. Haemopis septagon Sawyer & Shelley, 1976. Digestive tract of specimens from the Albemarle Peninsula, North Carolina. Comparison of the guts. A. Terrestrial individual (HS-4). B. “Aquatic” individual (HS-3). C. Juvenile individual (HS- 5). Of taxonomic significance, the pharynx in each case is prominently wide in relation to the crop, and extends posteriorly to ganglion XI (arrow), a unique feature among mid-Atlantic Hirudinidae. Furthermore, in each case the intestine consists of anterior and posterior regions, respectively (see text). Note the crop of the juvenile is segmentally compartmentalized and displays distinct anterior and posterior crop caeca per segment, a feature almost non-existent in adults (see also Fig. 8). acc XV, anterior crop caecum of segment XV; ai, anterior intestine; c, crop; gXIII, ganglion of segment XIII; gXIX, ganglion of segment XIX; p, pharynx; pcc XV, posterior crop caecum of segment XV; pcc XIX, posterior crop caecum of segment XIX; pi, posterior intestine; r, rectum.

FIGURE 8. Haemopis septagon Sawyer & Shelley, 1976. Dissected juvenile specimen from Albemarle Peninsula, North Carolina (HS-5) showing the mid-body crop is compartmentalized by sphincter-like muscle bands. Inset: schematic enlargement of consecutive segments XV and XVI, respectively, displaying anterior and posterior crop caeca per segment. Arrow indicates posterior position of pharynx (at segment XI). acc XV, anterior crop caecum of segment XV; c, crop; eb, ejaculatory bulb; gXVI, ganglion of segment XVI; mb, muscle band; n, nephridium of segment XVI; p, pharynx; pr, prostate; ps, penis sheath. Scale bar: 1.0 mm.

FIGURE 10. Haemopis septagon Sawyer & Shelley, 1976. Map of locality records. Haemopis septagon is currently known from the mid-Atlantic coastal plain from South Carolina to southern New Jersey. Scale bar: 100 km. See APPENDIX for compilation of locality records.