Proparadilepis Kornyushin et Greben 2014, gen. n.

Proparadilepis Kornyushin et Greben, gen. n.

T y p e s p e c i e s: Proparadilepis plegadissaakovae Kornyushin et Greben, sp. n..

D i a g n o s i s

Strobila of medium size, proglottides numerous. Scolex not clearly distinct from strobila. By slide, rostellar apparatus similar to cyclusteroid’s, but with less observable two muscular superficial layers, diagonal fibres not seen. Rostellum short, conical. Rostellar sac rather shallow, cup-shaped, weakly muscular. Suckers rounded, unarmed. Crown of 36 hooks in two rows. Difference in length between small and large hooks minor. Handle of hook longer than blade. Handle and guard rounded, with epiphyseal thickenings consisting of secondary tissue. Anterior part of strobila without external segmentation. Genital pores unilateral. Genital atrium simple. Testes four, arranged in line, usually one poral and three aporal to female organs. Cirrus-sac pear-shaped, not crossing poral osmoregulatory canals. Sperm duct forms loops at exit of cirrus-sac. Cirrus armed. Copulative part of vagina funnel-shaped. Conductive part of vagina ventral to cirrussac, posterior to its axis, sometimes posterior to cirrus-sac. Mature ovary consisting of two wings, lobed. Vitellarium compact, oval or transversely-oval. Fully-developed uterus sacciform, with shallow invaginations, filling entire segment. Eggs arranged closely to each other.

D i f f e r e n t i a l d i a g n o s i s

Proparadilepis gen. n. is similar to some members of the genus Paradilepis Hsü, 1935 in the number of rostellar hooks, in small number of the testes and in sac-like uterus (table 1). The genus Paradilepis consists of cestode parasites from Ciconiiformes, Pelecaniformes and Accipitriformes (Matevosyan, 1963; Bona, 1975). The new genus differs from the genus Paradilepis by the longer strobila, by the shape of rostellar hooks and by the armament of the cirrus. The handle of hook in the genus Proparadilepis gen. n. is longer than the blade; it is shorter than the blade in Paradilepis. The cirrus in the genus Proparadilepis gen. n. is uniformly armed by small spines; the spines are larger and scattered in Paradilepis.

Таблица 1. Морфологические особенности родов Mashonalepis, Paradilepis, Ascodilepis и Proparadilepis gen. n.

Note. Data for the genera Mashonalepis, Paradilepis and Ascodilepisare given after Bona (1975, 1994), Freeman (1954), Huey and Dronen (1981), Matevosyan (1963), Rausch (1949).

Proparadilepis gen. n. is also similar to the genus Ascodilepis Guildal, 1960 in small number of the testes and in sac-like uterus (table 1). The new genus differs from the genus Ascodilepis by the same characteristics as the genus Paradilepis. The genital organs in Proparadilepis gen. n. are without accessory structures, whereas the genital organs in the genus Ascodilepis are with accessory vagina and cirrus-sac.

Some morphological characteristics of Proparadilepis gen. n. are close to those of the genus Dendrouterina Fuhrmann, 1912. This genus includes cestodes parasitizing herons (family Ardeidae). The members of both genera have long strobila with numerous proglottides and the rostellar hooks are with relatively long handle. However, Proparadilepis gen. n. differs from the genus Dendrouterina by the number of rostellar hooks (36 vs 20), the number of the testes (4 vs 31–73) and the shape of mature uterus. The uterus of Proparadilepis gen. n. is sac-like while the uterus of Dendrouterina is arborescent, with numerous outgrowths.

We assign the new genus to the family Gryporhynchidae Spassky et Spasskaya, 1973; the validity of this family was first justified by Spassky and Spasskaya (1973). We take into account Bona’s opinion about independence of dilepidoid cestodes from ichthyophagous birds. This opinion on the cestode systematics Bona has expressed several times on the international workshops on cestode systematics and phylogeny. Position of the new genus in the system of the family Gryporhynchidae and in the “Keys to the cestode parasites vertebrates” (Bona, 1994) can be specified as following:

22 b. True rostellar pouch present or replaced by thick mass of longitudinal, concentric fibres; rostellar structure different, apex not like flat sucker. Hooks in two circles. Uterus always sacciform, wall persistent. Seminal receptacle either subspherical, median or transverse, porally elongate; reaches vitellarium...25

25 a. Rostellar pouch strong (wall not necessarily thick), very large; cavity at times negligible when rostellum retracted. Rostellum very complex, strong, stiff, with two muscular superficial layers, at least one of them consisting of diagonal, spiral fibres; cyclusteroid pattern. Pores either regularly alternate or unilateral, left. Vagina does not change dorsoventral position with respect to cirrus-sac in right and left pores. Scolex spherical, usually very large......................................................................................................26

25 b. Rostellar pouch replaced with dense spherical mass of longitudinal, concentric fibres, surrounding rostellum cap-wise when retracted, lying behind it, bent or transverse, when protruded. Rostellum simple, triangular, often stumpy, clearly formed by dense mass of longitudinal spiral fibres (not transverse circular), shortening and becoming compact pad when protruded; parvitaenioid pattern. Pores either irregularly alternate or unilateral with right and left strobilae in same species. Dorsoventral position of vagina to cirrus-sac inverted in right and left pores. Scolex either normal or spherical, large...............28

26 b. Pores unilateral. Testes four (seldom five or three). Ovary lobes compact, subspherical or scarcely lobulate. Uterus sacciform, forming two connected pouches, then one lobulate or ramified cavity.............27

27 a. Genital organs without accessory structures.............................................................................................27аа

27 а а. Vagina ventral to cirrus-sac, along its axis.................................................................. Paradilepis Hsü, 1935

27 a b 1. Vagina ventral and parallel to axis of cirrus-sac sometimes partly posterior of it.................................................................................................................................................................................... Proparadilepis gen. n.

27 b. Genital organs with accessory vagina and cirrus-sac. True vagina ventral and anterior to cirrus-sac............................................................................................................................................. Ascodilepis Guildal, 1960

28 b. Pores unilateral...................................................................................................................................................30

30 b. Osmoregulatory canals aporally inverted.......................................................................................................34

34 b. Hooks different in shape. Genital ducts dorsal to osmoregulatory canals. Testes postovarian, at times also aporally lateral or in anterior group. Uterus sacciform with crowded, deep, often digitiform, ramified lobules, cavity transversely extended, or horseshoe-shaped with near extremities or circular with anterior ramified branch.............................................................................................................................34 b a

34 b a 1. Hooks of anterior and posterior rows essentially different in length, up to 15 (ratio of hook lengths in different rows 1.25–1.59). All testes in posterior part of median field of proglottis, ovary and vitellarium displaced to anterior margin of proglottis. Gravid uterus horseshoe-shaped. Tubular part of uterus forms two branches along elongated proglottis, digitiform lobules across proglottis........................................................................................................................................................... Dendrouterina Fuhrmann, 19122.

34 b b 1. Hooks of anterior and posterior rows less different up to 1–5. Testes rounding aporal wing of ovary, forming small anterior group. Tubular part of uterus situated across proglottis, digitiform lobules directed ateriorly or posteriorly................................................................ Mashonalepis Beverly-Burton, 1960