Centrorhynchus millerae, R. & Smales, 2013

Smales, Lesley R., 2013, Acanthocephala including the descriptions of new species of Centrorhynchus (Centrorhynchidae) and the redescription of Lueheia inscripta (Westrumb, 1821) (Plagiorhynchidae) from birds from Paraguay South America, Revue suisse de Zoologie 120 (2), pp. 175-202 : 186-188

Centrorhynchus millerae sp. n. Figs 20-27

MATERIAL EXAMINED: MNHG-INVE-82720; holotype, male, from Megascops choliba (Vieillot, 1817) , small intestine: Paraguay, Arroyo Agua-Pey , 25.10.1986 . – MNHG-INVE- 82721; paratype (allotype) female, from Megascops choliba (Vieillot, 1817) , small intestine: Paraguay, Arroyo Agua-Pey , 25.10.1986 . – MNHG-INVE-38444, paratypes 3 pieces female from Megascops choliba (Vieillot, 1817) , small intestine: Paraguay, Arroyo Agua-Pey , 25.10.1986 . – MNHG-INVE-38443; voucher specimens, 4 females, 6 pieces female from M. choliba , small intestine: Paraguay, Arroyo Agua-Pey , 10.10.1982 .

ETYMOLOGY: This species is named in honour of the Director of the South

Australian Museum.

DESCRIPTION

General: (based on 1 male, 5 females, and 6 pieces of females) Trunk spineless, elongated; dilated anteriorly in region of testes in male, with swollen posterior end terminating in digitiform process in female. Neck shorter than broad. Proboscis in 2 parts, widest at base, with constriction at insertion of proboscis receptacle about 60% of distance from apex to proboscis base, anterior proboscis slightly expanded anterior to constriction. Proboscis armature 30-32 longitudinal rows 17-20 hooks, showing sexual FIGS 20-27

Centrorhynchus millerae sp. n. (20) Female proboscis hooks, longitudinal row true hooks 1-6. (21) Female proboscis hooks, longitudinal row 11 spiniform hooks. (22) Egg. (23) Male. (24) Female, anterior end. (25) Female proboscis hooks, longitudinal rows 2-3 transitional hooks. (26) Male proboscis hooks, showing true hooks with simple roots and 1-2 hooks with reduced roots. (27) Female reproductive tract. Scale bars: 20, 22, 25, 26, 25 µm; 21, 12.5 µm; 23, 1 mm; 24, 27, 400 µm.

dimorphism. Male: in each longitudinal row first 5-6 hooks with large simple roots, blades 20-50 long, blades hooks 3, 45-50, longest, blades hooks 1, 6, 20-30, shortest; next hook with reduced root, blade 18-20 long, next 10-14 hooks spiniform, blades 11-15 long. Female: in each longitudinal row first 5-6 hooks with large simple roots, blades hooks 3 longest, blades hooks 1, 6 shortest; 3-4 transitional hooks with manubria, blades 20-25 long; next 9-12 hooks spiniform, blades 10-15 long, inserted on posterior part of proboscis. Neck spineless, shorter than broad. Proboscis receptacle double walled. Lemnisci elongated, claviform, inserted at base of neck, extend posteriorly beyond proboscis receptacle. Cerebral ganglion located at mid region of proboscis receptacle, posterior to neck.

Male: (based one specimen) Trunk 13 mm long, 1700 at widest part. Proboscis partly inverted estimated length 650, width 302. Neck 221 long, 370 wide at base. Proboscis receptacle 1200 long, 308 wide; lemnisci 1250 long. Testes oval, tandem, contiguous, in anterior third of trunk; anterior testis 536 long, 402 wide; posterior testis 536 long, 375 wide. Cement glands, 3 or 4 (number not determined), elongated, tubular, begin immediately posterior to end of posterior testis, 8800 long; Saefftigen’s pouch 1300 long. Genital pore terminal. Entire male system occupies about 80% trunk length.

Female: (Based on 5 specimens) trunk 25-35 (29.5) mm long, 470-590 (575) wide. Proboscis 850-900 (875) long, 280-320 (299) wide. Neck 155-270 (203) long, 402-435 (420) wide at base. Proboscis receptacle 1226-1810 (1409) long, 205-340 (267) wide. Lemnisci 1445-1700 (1509) long. Reproductive tract, uterine bell to genital pore, 900-2250 (1575) long. Genital pore subterminal. Eggs oval, external shell thick, ridged, 49.5-56.0 (53.1) long, 23.0-29.5 (26.7) wide.

COMMENTS: Centrorhynchus millerae sp. n. conforms to the diagnosis of the genus given by Golvan (1956, 1960). Centrorhynchus millerae differs from all species of Centrorhynchus , except C. geranoaeti , in that only the females have a proboscis armature with transitional hooks. Centrorhynchus millerae differs from C. geranoaeti in the number hooks per row (16-20, of which 5-7 are true hooks compared with 22-24, 8-12) and the form of the transitional hooks, with lateral alate processes on the manubria for C. millerae , without for C. geranoaeti . Centrorhynchus millerae has a shorter proboscis and longer cement glands than C. geranoaeti (Table 3). Centrorhynchus millerae occurs in the passerine, Pitangus sulfuratus, the great kiskadee and C. geranoaeti in the strigiform, Megascops cholida , the tropical screech owl.

In the key to the Neotropical species of Centrorhynchus ( Lunaschi & Drago, 2010) C. millerae , clusters together with C. guira and C. kuntzi as a third species with lateral alate processes on the transitional hooks. Centrorhynchus millerae is closest to, but differs from, C. guira in the number and arrangement of hooks of the proboscis armature (30-32 rows of 16-20 hooks compared with 32 rows of 16-19 hooks). Centrorhynchus millerae further differs from C. guira in having fewer true hooks and more spiniform hooks per row (5-6 and 9-14 compared with 7-9 and 6-7). Centrorhynchus millerae is a smaller worm than C. guira and has shorter lemnisci, smaller testes, shorter cement glands and shorter female reproductive tract (Table 3).

Centrorhynchus simplex , also from South America, and each of the species of Centrorhynchus from North America, as discussed above for C. geranoaeti , can be further distinguished from C. millerae by their proboscis armature, having differing combinations of true and spiniform hooks and no transitional hooks.