Helobdella modesta

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 : 69

Helobdella modesta

( Figs. 2B – 7B )

(LSID: urn:lsid:zoobank.org:act:FBFD74DE-57A7-4C98-8514- 51559DD2270C)—

Dorsal body light to yellowish-grey, sometimes with greenish tint. Dark, circular/ovoid spots scattered all over the body, less numerous along the dorsal median stripe, especially intensive around gonopores. Ventral color creamy-yellow or transparent aureate. Total of 67 annuli. Scute usually settled on 12th annulus (on VII-a1) but sometimes extended up to half of 13th annulus. One pair triangular eyes situated on the third annulus ( Fig. 7B ). Male and female gonopores located between XI a2/a3 (24th/25th annulus) and XIa3/XIIa1 (25th/26th annulus), respectively; separated by one annulus. Clitellum located between XI-XIIth segments. Six pairs of ovoid, serrated and ruffled testisacs inter-segmentally arranged at XIII to XVIII. Ejaculatory bulbs similiar to H. stagnalis . Ovisacs large, connected with long and curled common oviduct. Length of ovisacs and oviduct are almost equal ( Figs. 2B , 4B ). Six pairs of crop caeca, sixth extends to end of fourth intestinal caecum. Four pairs of thin and curved downward intestinal caeca. Rectum is “S” shaped, longer than that of H. stagnalis ( Figs. 3B , 5B ).

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.