Helobdella serendipitious, Saglam & Kutschera & Saunders & Saidel & Balombini & Shain, 2018

Saglam, Naim, Kutschera, Ulrich, Saunders, Ralph, Saidel, William M., Balombini, Katherine L. W. & Shain, Daniel H., 2018, Phylogenetic and morphological resolution of the Helobdella stagnalis species-complex (Annelida: Clitellata: Hirudinea), Zootaxa 4403 (1), pp. 61-86 : 70

Helobdella serendipitious n. sp.

( Figs. 2C – 7C )

(Holotype: ANSP GI 19495)

(LSID: urn:lsid:zoobank.org:act:D2A31CAB-F69D-413A-AD52-1497EB146753)—

Adult 11.2–20.3 mm long, 4.5–5.2 mm wide, width of anterior sucker 1.2–2.4 mm, width of posterior sucker 2.0– 3.6 mm. Dorsal body light to yellowish-grey, sometimes with greenish tint. Ventral color containing mixed translucent creamy and browngreenish spots. Total of 66 annuli; I, II, III uniannulate, IV, V biannulate, VI-XXIII triannulate, XXIV biannulate XXV-XXVII uniannulate. One pair of large circular eyes clearly separated on segment III ( Fig. 7C ). Gonopores located between XI a1/a2 (23th/24th annulus) and XI a2/a3 (24th/25th annulus), respectively. Clitellum on 11th segment. Six pairs of ovoidal, irregular and amorphous testisacs inter-segmentally arranged on XII/XIII–XVII/ XVIII. Ejaculatory bulbs moderately longer, elongated ellipsoid, lying at much lower level by the sides of the atrium, connected by slender ejaculatory ducts with sharp turn backwards into atrium in XI. Ovisacs large, connected with long and curled common oviduct. Length of ovisacs and oviduct almost equal. Ovisac and oviduct 2/3 the length of vas deferens ( Figs. 2C , 4C ). Crop caeca comprising six unbranched pairs. Four pairs thick intestinal caecum curved downward in first and fourth pairs. Rectum short, “S” shaped and similar to that of H. stagnalis . ( Figs. 3C , 5C ).

Figures

FIGURE 2. Position of reproductive morphology of Helobdella species. A, Helobdella stagnalis; B, Helobdella modesta; C, Helobdella serendipitous n. sp.; D, Helobdella eriensis n. sp.; E, Helobdella echoensis n. sp. ac: atrial cornua; an, anus; e, eyes; fg, female gonopore; ic, intestinal caecum; mg, male gonopore; od, oviduct; os: ovisac; ps, posterior sucker; r, rectum; s, scute; sd, sperm duct; t, testisac, vd. vas deferens.

FIGURE 3. Position of digestive system of Helobdella species. A, Helobdella stagnalis; B, Helobdella modesta; C, Helobdella serendipitous n. sp.; D, Helobdella eriensis n. sp.; E, Helobdella echoensis n. sp. ac: atrial cornua; an, anus; cc, corp caecum; e, eyes; ic, intestinal caecum; p, proboscis;ps, posterior sucker; r, rectum; s, scute.

FIGURE 4. Dorsal view of reproductive system of Helobdella species. A, Helobdella stagnalis; B, Helobdella modesta; C, Helobdella serendipitous n. sp.; D, Helobdella eriensis n. sp.; E, Helobdella echoensis n. sp. a, atrium; ac: atrial cornua; os: ovisac; od, oviduct; sd, sperm duct; t, testisac, vd. vas deferens.

FIGURE 5. Digestive system of Helobdella species. A, Helobdella stagnalis; B, Helobdella modesta; C, Helobdella serendipitous n. sp.; D, Helobdella eriensis n. sp.; E, Helobdella echoensis n. sp. an, anus; cc, corp caecum; ic, intestinal caecum, r, rectum.

FIGURE 7. Eye position and shape of Helobdella species. A, Helobdella stagnalis; B, Helobdella modesta; C, Helobdella serendipitousn. sp.; D, Helobdella eriensis n. sp.; E, Helobdella echoensis n. sp.