Spiniglans beveridgei, Mariaux & Georgiev, 2018

Mariaux, Jean & Georgiev, Boyko B., 2018, Seven new species of cestode parasites (Neodermata, Platyhelminthes) from Australian birds, European Journal of Taxonomy 440, pp. 1-42 : 8-11

Spiniglans beveridgei sp. nov.

urn:lsid:zoobank.org:act:A7F42F63-A54F-4165-BDF1-FE21F47DA734

Figs 7–11 , Table 2

Etymology

The species is dedicated to Professor Ian Beveridge, a friend and colleague, collector of this material, in recognition of his major contribution to systematic helminthology.

Material examined

Holotype

AUSTRALIA: Victoria, Geelong , 38°8′ S, 144°22′ E, 22 Apr. 2001, Ian Beveridge leg. (AHC 36467).

Paratypes

AUSTRALIA: 10 specs, same data as for holotype (AHC 36468–36477).

Type host

Corvus mellori Matthews, 1912 ( Passeriformes , Corvidae ).

Intensity

About 55 specimens in a single host, together with S. whittingtoni sp. nov.

Description

Body of medium size with length 57–63 mm and maximum width 1050–1280 (1170, n = 6) at level of late mature proglottides. Most complete late mature to pregravid specimens consisting of 169–198 proglottides. Proglottides craspedote, initially wider than long, progressively becoming longer, square at mature stage and longer than wide at late mature stage. Ventral osmoregulatory canals connected posteriorly in each proglottis by transverse anastomosis. Longitudinal musculature with well-marked bundles. Scolex ( Fig. 7 ) rounded, well marked, sometimes showing a transverse fold behind suckers, with diameter 325–450 (397, n = 6). Suckers strong, rounded, 145–180 in diameter (161, n = 24), unarmed. Rostellar apparatus musculo-glandular, with developed glandular tissue along whole rostellar sac length often slightly protruding apically even when retracted. Rostellar sac well-delineated, 374–450 × 132– 152 (383 × 142, n = 6) tapering posteriorly, extending beyond level of posterior margin of suckers, often with terminal bubble-like extension. Rostellum oval, strongly muscular, with well-marked constriction behind hooks, 224–270 × 85–105 (242 × 94, n = 6). Rostellar hooks ( Fig. 8 ) in two mostly regular rows (with occasional slight irregularities or indistinct row delineation), 20 (n = 1), 21 (n = 3) or 22 (n = 4) in number, robust, with strong guard and slightly bent tapering extremity of handle. Anterior hooks 40.5–44 (42, n = 8), posterior hooks 38.5–40.5 (39.5, n = 6). Proglottization distinct at 500–650 (568, n = 7) from posterior margin of suckers Genital pores anterior situated at about 20% of length of lateral proglottis margin, irregularly alternating in short series, e.g., …1, 1, 2, 2, 1, 1, 3, 1, 1, 2, 2, 3, 1, 4, 5, 3, 1, 1, 2... No more than five consecutive pores observed on single side. Genital ducts passing between osmoregulatory canals. Genital atrium small.

Testes 40–58 (49, n = 54) in number (43–55 in 90% of counts), in one or two layers, in one continuous posterior file, denser posteriorly, mostly extending antero-laterally up to level of vitellarium but a few may be more anterior, especially at antiporal side, occasionally overlapping osmoregulatory canals ( Fig. 9 ). External vas deferens 13.5–21 in diameter (17, n = 15), highly convoluted in the antero-poral part of proglottis, not overlapping cirrus-sac. Cirrus-sac short, oval or bean-shaped, 87–118 × 47–68 (102 × 55, n = 44), transverse or slightly curved anteriorly, rarely reaching poral osmoregulatory canals. Internal vas deferens coiled, making several large loops within cirrus-sac. Cirrus armed with compact tuft of fine bristle-like spines about 35 long ( Fig. 10 ).

Vitellarium central, transversely elongated, lobate, variable in shape. Ovary transversely elongated, deeply and finely branched, lobulate, bi-alate, antiporal wing much larger than poral one. Mehlis’ gland 70–105 (84, n = 15) closely anterior to vitellarium. Seminal receptacle initially round, rapidly becoming oval, reaching up to 175 × 114, dorsal, posterior to external vas deferens, often over poral ovary wing. Vagina thick-walled, along posterior margin of cirrus-sac, mostly straight 7.5–11.5 in diameter (9.5

n = 12), externally gained with loose parenchymal cells. Vaginal pore posterior to pore of cirrus-sac. Young uterus reticular ( Fig. 11 ) in pregravid proglottides. Gravid segments and eggs not observed.

Remarks

The genus Spiniglans Yamaguti, 1959 has been discussed by Bona (1994), Salamatin (1999) and Kornyushin et al. (2009). The latter authors briefly reviewed the generic characters and listed 4 valid species, from Corvidae in the Old World, as well a few other closely related taxa possibly belonging to the genus. They also predicted that more taxa in this group would be found both in other European and tropical corvid species.

Our material can easily be distinguished from most presently recognized species in the genus ( Table 2). It differs from S. microsoma ( Southwell, 1922) by having more testes; from S. affinis ( Krabbe, 1869) by smaller rostellar hooks, fewer testes and a smaller rostellum ; from S. constricta (Molin, 1858) by a larger cirrus-sac, rostellar pouch and rostellum ; from S. pirinica ( Georgiev, Kornyushin & Genov, 1987) by much shorter hooks and a smaller cirrus-sac. Our material most closely resembles S. sharpiloi Kornyushin et al., 2009 but can be distinguished from it by slightly larger rostellar hooks and a longer rostellar pouch and rostellum . It is also similar to S. corvi ( Joyeux, Baer & Martin, 1937) but it has more testes and a shorter cirrus-sac. In consequence, we consider it to belong to a new species, Spiniglans beveridgei sp. nov.

Up to now, Spiniglans was known from the Old World only and its host range essentially limited to the Corvidae although the type species was reported in granivore passerines ( Emberizidae and Ploceidae ) in captivity ( Southwell 1922). Its presence in Australia may be due to a recent importation as Corvus colonized (or re-colonized) this continent after diversifying in the Palaearctic ( Ericson et al. 2005; Haring et al. 2012). The Corvidae includes around 130 species and is cosmopolitan. It is therefore expected that a larger diversity of parasites of this genus is still unknown, especially in Asia. It remains to be seen whether New World corvids are also hosts of these cestodes, as hinted by the brief report of Pfaffenberger & Butler (1981) of S. constricta (“ Anomotania constricta ”) in Corvus cryptoleucus Couch, 1854 in New Mexico. If confirmed, many more Spiniglans spp. are likely to be discovered in American corvids as the family is highly diversified in the Americas.

Figures

Figs 7–11. Spiniglans beveridgei sp. nov. 7. Scolex. 8. Hooks. 9. Mature proglottis. 10. Terminal genitalia. 11. Pregravid proglottis with young reticular uterus. Scale bars: 7 = 100 µm; 8 = 20 µm; 9 = 200 µm; 10 = 50 µm; 11 = 500 µm.