A New Leech Species (Clitellata: Hirudinida: Piscicolidae) from the Łyna River Near Olsztyn, Poland
A new species of fish leech from Poland, Piscicola burresoni n. sp. (Piscicolidae), is described. The leech was found in 2007 on stones and on pike (Esox lucius L.) and chub (Leuciscus cephalus L.) in the Łyna River, Poland. The leech is small, relatively flattened, with a prominent coarctation between the trachelosome and urosome. The pigmentation is unique to the new species and it has 14 annuli with gonopores separated by 4 annuli. The receptaculum seminis consists of an elliptical aperture located at a distance of 3 annuli behind the female gonopore. The copulatory area on the clitellum is characteristic in the shape of a parallel ellipse. The vector tissue is in the form of a transverse plate below the oviduct outlet. For a complete description of the external morphology, a geometric–mathematical model of the leech body form was used.Abstract:
Piscicola burresoni n. sp. (10, 11 = holotype; 12, 13 = paratype). (10) Dorsal side (scale bar = 0.83 mm), re-touched to show body coloration. (11) Ventral side (scale bar = 0.83 mm). (12) Dorsal side, prominent difference between d3 and d4 (scale bar = 0.62 mm). (13) Ventral side (scale bar = 0.66 mm).
Model of leech body form. (1) Model of the body. (2) Transverse section through the trachelosome. (3) Transverse section through the urosome.
Body form of Piscicola burresoni n. sp. (4) Model of the body. (5) Transverse sections through the trachelosome and urosome. Piscicola margaritae (6) Model of the body. (7) Transverse sections through the trachelosome and urosome.
Tree diagram (8) for 21 species (Piscicolinae) based on the mean value of 19 body proportion indices (Ward's method, Manhattan distance). (9) Tree diagram for 21 species (Piscicolinae) based on 113 characters (Ward's method, Manhattan distance).
Piscicola burresoni n. sp. (alimentary tract of the holotype). (14) Crop cecum (scale bar = 0.25 mm). (15) Posterior crop cecum (scale bar = 0.39 mm). (16) Five intestinal diverticula (ID) (scale bar = 0.39 mm).
Piscicola burresoni n. sp. Reproductive system (17, 19 = holotype), (20 = other material). (17) External reproductive structures; male (M) and female (F) gonopores, copulatory area (CA), and receptaculum seminis (RS) (scale bar = 0.15 mm). (18) Scheme of the reproductive system (scale bar = 0.16 mm). (19) General view of the reproductive system after removing the left ovary (scale bar = 0.16 mm). (20) Reproductive system of the other specimen (scale bar = 0.16 mm). (21) Lateral view of the reproductive system; A = atrium, CS = conducting strands of vector tissue, ED = ejaculatory duct, O = ovisac, P = proboscis, PG = prostate glands, T1 = first pair of testisacs, T2 = second pair of testisacs, SV = seminal vesicle, VT = vector tissue.
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