Morphological Phylogeny of Leeches


Character 1. Chaetae: present (0); absent (1).

Character 2. Testisacs: 1 pair (0); >1 pair (1).

Character 3. Coelomic organization: open with complete septa (0); reduced to lacunae without complete septa.

Character 4. Presence of conducting (vector) tissue for passage of sperm from copulatory area to female reproductive tissues: present (0); absent (1). In Americobdella valvidiana there is a pair of ducts connecting the male atrium and the female ovarian ducts near the female gonopore (Moore 1925; Cabellero 1941, 1956). Given the similarities of form, and ostensibly of function, this feature was considered a priori to be homologous with structures better known from the piscicolid leeches .

Character 5. Nephridia: complete in genital somites (0); suppressed in genital somites (1).

Character 6. Pharynx: not protrusible (0), ; modified into protrusible proboscis (1), .

Character 7. Intestine: acaecate (0); caecate (1).

Character 8. Cephalic eyespots: arranged peripherally, i.e., dorsolateral (0), (see Figure 3a, b, c); arranged medially, i.e., dorsal (1),. In taxa where some of the photoreceptors were ambiguously positioned, the most posterior pair served as the defining criterion.

Character 9. Coelomic architecture: located entirely internal to the circular muscle layer (0), ; located, in part, external to the circular muscle layer (1), .

Character 10. Laterally arranged processes on post-clitellar somites: absent (0); present (1).

Character 11. Dorsal blood vessel modified posteriorly into a sinus enclosing the intestinal tissue: absent (0); present (1).

Character 12. Body shape: vermiform (0); dorsoventrally flattened (1).

Character 13. Significant muscularization of lateral coelomic spaces: present (1); absent (0).

Character 14. Surface covering of cocoons: proteinaceous (0); membraneous (1).

Character 15. Deposition of cocoons: slipped off head (0); secreted ventrally (1).

Character 16. Arrangement of salivary tissue: diffuse (0); discrete glands (1).

Character 17. Dorsal and ventral blood vessels: present (0); absent (1).

Character 18. Pharyngeal folds fused anteriorly into myognaths: absent (0); present (1), .

Character 19. Velar mouth: continuous (0); modified to form paragnaths (1).

Character 20. Number of testisacs attached to a vas deferens in a somite: 1 (0), ; more than 1 (1), .

Character 21. Male bursa: bilobed (0), (see Figure 6d, f, g, h); single bulb (1), .

Character 22. Ovisacs: more than three somites in length (0); not more than two somites long (1).

Character 23. Eyespots: one pair per annulus (0); at least two pairs per annulus (1), .

Character 24. Accessory ventral copulatory gland pores: absent (0); present (1).

Character 25. Myognaths: armed (0); unarmed (1).

Character 26. Testisacs: discretely arranged on vasa deferentia (0); hundreds of sacs profusely arranged on vasa deferentia (1). .

Character 27. Ovisacs: tubular (0), (see Figure 7e-h); spheriod (1), .

Character 28. Nephridia: each with single funnel (0), ; each with multiple funnels located in ciliated organ (1).

Character 29. Urinary bladder: absent (0); present (1), .

Character 30. Cocoons: cemented to a substrate (0); not cemented to a substrate (1).

Character 31. Female median reproductive apparatus: simple pocket (0), ; modified into vaginal tube (1), .

Character 32. Respiratory auricles adjacent to caudal sucker: absent (0); present (1).

Character 33. Nephropores: ventromedial (0); ventrolateral (1).

Character 34. Myognaths: 3 (0); 2 (1).

Character 35. Elongation of male atrium into penis sheath with protrusible penis: absent (0); present (1), . Species of the genus Theromyzon are reported to have a penile apparatus (Wilkialis and Davies 1980), as are some piscicolids. In the latter the structure is clearly eversible as opposed to protrusible and was not considered homologous with the penis present in some arhynchobdellids.

Character 36. Sperm duct (efferent to the epididymis): without prominent ejaculatory bulb (0); with prominent ejaculatory bulb (1), .

Character 37. Epididymes: loosely arranged (0); tightly coiled mass (1), .

Character 38. Cocoons: without spongy covering (0); with spongy covering (1).

Character 39. Common oviduct: shorter than oviducts (0); longer than oviducts (1), .

Character 40. Epididymes: arranged terminal to the afferent region of sperm ducts (0), ; recurved and closely associated along the sperm ducts (1).

Character 41. Armature on myognaths: monostichodont (0); distichodont (1), .

Character 42. Penis sheath: regions efferent and afferent to fold of approximately equal length (0); efferent region substantially longer than afferent region (1); afferent region substantially longer than efferent region (2).

Character 43. Vagina: with post-oviduct caecum (0),; without post-oviduct caecum (1).

Character 44. Crop caeca: unbranched (0); branched (1).

Character 45. Efferent sperm duct: with single flexure (0); with double flexure (1) .