Centrorhynchus polissiensis Lisitsyna, Greben, 2015

Lisitsyna, O. I. & Greben, O. B., 2015, Acanthocephalans Of The Genus Centrorhynchus (Palaeacanthocephala, Centrorhynchydae) From Birds Of Ukraine With The Description Of A New Species, Vestnik Zoologii 49 (3), pp. 195-210 : 205-206

Centrorhynchus polissiensis Lisitsyna, Greben , sp. n.

( fig. 5 , A–D)

T y p e h o s t. Common buzzard Buteo buteo (L.) ( Aves , Falconiformes , Accipitridae ).

T y p e l o c a l i t y. Zazimye , Brovary District, Kiev Region, Ukraine.

S i t e. Intestine.

T y p e m a t e r i a l. Male holotype. AH3 ( SIZK); paratypes, AP. 3.1–3.6 ( SIZK) .

E t y m o l o g y. This species is named after the bio-geographical region Polissya (forest zone).

G e n e r a l (4 {, 2}). Trunk long, almost cylindrical. Proboscis division into two parts of constriction. Anterior part oval or spatulate, posterior part conical. Neck implict. Proboscis with 28–30 longitudinal rows of 19–20 hooks. First 12–13 hooks at anterior part up to constriction, remainder hooks – before constriction. First 4–6 (5) hooks large with posteriorly directed strong roots. Next 3–4 transitional with roots consisting of 2 antero-lateral alate processes, remaining hooks spiniform with anteriorly directed simple roots ( fig. 5 , A). Largest hook blade in 2 nd, largest hook root in 4 th. The least blades and roots in transitional hooks. Blade thickness increasing from first to 4th hooks, then gradually decreasing. The last 2–4 hooks without roots. Proboscis receptacle double-walled, attaching in middle proboscis. Lemnisci sacciform, longer than proboscis receptacle. Gonopore subterminal in both sexes.

M a l e s. Trunk 14.14–16.69 mm long, with maximum width in anterior part 1100–1230. Proboscis 1020–1120 long, up to constriction 480–550 length with maximal width in anterior part 400–450, width in constriction 280–440. Proboscis with 28–30 longitudinal rows of 19–20 hooks. First 4–5 (5) hooks large with posteriorly directed strong roots. Hook blade length: 1, 48–65; 2, 65–70; 3, 55–65; 4, 53–63; 5, 45–55. Hook blade thickness: 1, 10–13; 2, 13–15; 3, 15–18; 4, 20–25; 5, 20–25. Hook root length: 1, 45–60; 2, 65–70; 3, 63–70; 4, 75–83; 5, 38–70. Transitional hook blade length 38–40, 10–13 thick, hook root 20–25 long. Spiniform hook blade length 40–43, hook root processes up 20. Proboscis receptacle 1300–1600 long with maximal width 300–420. Lemnisci 1220–1330 long, fall short of testes. Testes in tandem slightly diagonally or at 350–400 long. First testis 780–850 × 350–520, second testis 650–950 × 430–510. Cement glands tubulate, one longer than others, reach before posterior end of posterior testis, two others of the same length. Cement glands 8.30–9.65 mm long. Säfftigen pouch 1050–1900 long.

F e m a l e s. Trunk 20.80–24.00 mm long, with maximum width in anterior part 920–1100. Proboscis 1080–1200 long with maximal width at anterior part 450–480, anterior part of proboscis up to constriction 480–530 long width at constriction 370. Proboscis with 30 longitudinal rows of 19–20 hooks. First 5–6 large with strong roots directed posteriorly. Largest hook blade length: 1, 55–63; 2, 70–73; 3, 60–68; 4, 58–63; 5, 50–55; 6, 40–45. Hook blade thickness: 1, 13; 2, 15; 3, 18; 4, 20–23; 5, 20–25; 6, 13–20. Hook root length: 1, 38–60; 2, 63–68; 3, 63–73; 4, 75–85; 5, 73–83; 6, 30–55. Transitional hook blade length 38–40, 13 thick, hook root 25–30 long. Spiniform hook blade length 40–43, hook root processes up 20. Proboscis receptacle 1460–1550 long with maximal width 300. Reproductive tract consist of vagina with two sphincters, uterus and uterine ball. Eggs elongate-oval, without polar prolongation of fertilization membrane, 45–55 × 25.

Рис. 5. Centrorhynchus polissiensis sp. n. от Buteo buteo : A — крючья продольного ряда, голотип, {; B — общий вид, голотип, {; C — хоботок, голотип, {; D — яйцо (оригинал).

D i f f e r e n t i a l d i a g n o s i s. According to the latest global review on acanthocephalans ( Amin, 2013), the genus Centrorhynchus includes 95 species. Among them 8 species have the proboscis armament similar to that in C. polissiensis sp. n.: C. albidus Meyer, 1932 [30 × 20–22], C. aluconis (Muller, 1780) Lühe, 1911 [30–34 × 15–17], C. amphibius Das, 1950 [26–30 × 20–21], C. brama Rengaraju, Das, 1980 [28 × 20], C. conspectus Van Cleave, Pratt, 1940 [26–32 × 17–19], C. globocaudatus (Zeder, 1800) [26–32 × 18–22], C. guira Lunaschi, Drago, 2010 [29–32 × 18–19], C. javanicus Rengaraju, Das, 1975 [28 × 19]. However, new species can not be assigned to any of them based on other characteristics. In particular, C. albidus has at least 7, and C. guira has 8–9 first hooks in each row with large blades and powerful roots (Meyer, 1932; Lunaschi, Drago, 2010) vs 4–6, more often 5 in C. polissiensis sp. n. In C. javanicus and C. brama the anterior part of the proboscis bears first 10 hooks of each longitudinal row ( Rengaraju, Das, 1975, 1980) vs 12–13 hooks in C. polissiensis sp. n. The anterior part of the proboscis in C. amphibius is almost cylindrical, and the blade length of the largest hooks on anterior part of the proboscis is not more than 42 ( Das, 1950), whereas in C. polissiensis sp. n. the bulb is formed on anterior part of the proboscis and the length of the blade of the second, the largest hook of C. polissiensis sp. n. is 65–70 in males and 70–73 in females. C. polissiensis sp. n. is most similar to C. aluconis , C. conspectus and C. globocaudatus . The transitional hooks of all four species have roots with lateral processes. The shape of the proboscis in C. polissiensis sp. n., C. aluconis and C. conspectus is similar, transitional hook roots of these three species have alate processes (Meyer, 1932; Petrochenko, 1958; Khohlova, 1986; Dimitrova, Gibson, 2005). However, C. polissiensis sp. n. has different number of hooks in a longitudinal row of the proboscis and smaller eggs. Thus, C. aluconis has 13–17 hooks in longitudinal row, C. conspectus — 17–18 hooks vs 19–20 in C. polissiensis sp. n. Also, both species have larger eggs: 56–65 × 28–30 in C. aluconis , 68–72 × 33–35 in C. conspectus vs 45–55 × 25 in C. polissiensis sp. n. C. globocaudatus differs from C. polissiensis sp. n. in shape and morphology of the proboscis hooks. Narrowing of the proboscis in C. globocaudatus is inconspicuous, so the proboscis is close to the conical shape, while in C. polissiensis sp. n. the narrowing is expressed clearly and separates the bulbous anterior and conical posterior parts of proboscis. Thickness of the blade in larger hooks of C. globocaudatus does not exceed 18 vs 20–25 in C. polissiensis sp. n. In addition, the roots of the transitional hooks of C. globocaudatus have alate root processes provided with lateral “X”-shaped processes vs wing-shaped root processes of transitional hooks in C. polissiensis sp. n.

Figures

Fig. 5. Centrorhynchus polissiensis sp. n. from Buteo buteo: A — hooks of a longitudinal row, holotype, {; B — total view, holotype, {; C — proboscis, holotype, {; D — egg (original).