Centrorhynchus viarius, 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 : 192-196

Centrorhynchus viarius n. sp. Figs 38-43

MATERIAL EXAMINED: MHNG-INVE-82724; holotype, male, from Buteogallus meridionalis (Latham, 1790) , small intestine; Paraguay, Transchaco 293, Pte Hayes; 04.11.1983 . – MHNG-INVE-82725, paratype (allotype), female, from Buteogallus meridionalis (Latham, 1790) , small intestine; Paraguay, Transchaco 293, Pte Hayes; 04.11.1983 . – MHNG-INVE- 38393; paratypes from Buteogallus meridionalis (Latham, 1790) , small intestine; Paraguay, Transchaco 293, Pte Hayes; 04.11.1983 . – MHNG-INVE-38455, voucher specimens, 1 female, from Buteogallus meridionalis (Latham, 1790) , small intestine; Paraguay, Transchaco 293, Pte Hayes; 05.07.1985 . – MNHG-INVE-38459, 38456, 38457, 383843, juvenile males, pieces of males, 5 females, pieces of females from Buteo magnirostris (Gmelin, 1788), small intestine; Paraguay, Transchaco 95, 110, 15 km E from Cerrito, Pratts Gill, 12.10.1982 , 01.08.1951995, 01. 07.1995, 07.11.1987. – MHNG-INVE-38388, 1 female from Buteogallus urubitinga (Gmelin, 1788) , small intestine; Paraguay, Transchaco 70, 24.10.1988 . – MNHG-INVE-38385, 1 male, 5 pieces female from Parabuteo uncinatus (Temminck, 1824), small intestine; Paraguay, Transchaco 115, 07.11.1987 .

ETYMOLOGY: The species name is taken from viari, of the roadside, and refers to the fact that all the hosts were collected from along the Transchaco.

DESCRIPTION

General: (based on 5 males, 3 juvenile males, 14 pieces of male, 12 females and 35 pieces of female) Trunk spineless, elongated, more or less cylindrical, dilated anteriorly in region of testes. Neck shorter than broad. Proboscis in 2 parts, with constriction at insertion of proboscis receptacle at about 50% of distance from apex to proboscis base; anterior proboscis slightly expanded above constriction. Proboscis armed with 28-30 rows 23-27 hooks, lengths of hook blades vary irregularly along each row, longest blades usually hooks 3-5, shortest blades, usually hooks 19-22. Anterior 8-9 hooks with large simple roots, blades hooks 2, 35 long, hooks 3, 32, 38 long, hooks 4, 38, 40 long, hooks 5, 20-40 long, hooks 6, 35-40 long, hooks 7, 30-40 long, hooks 8, 20-32 long, hooks 9, 25 long; next 4-5 hooks transitional, blades 18-30 long; posterior 12-13 hooks spiniform, inserted on posterior part of proboscis, longest blades last 2 hooks in row, 10-30 long. Neck spineless, shorter than broad. Proboscis receptacle double walled. Lemnisci tubular, inserted at base of neck, extend posteriorly FIGS 38-43

Centrorhynchus viarius sp. n. (38) Male. (39) Male proboscis, showing armature. (40) Proboscis hooks, longitudinal rows of true hooks 3-7, 2-8, and transitional hooks 5, 4. (41) Female reproductive tract. (42) Proboscis hooks, longitudinal rows of spiniform hooks 13, 14. (43) Egg. Scale bars: 38, 1 mm; 39, 200 µm; 40, 42, 43 25 µm; 41, 100 µm.

beyond proboscis receptacle. Cerebral ganglion located at mid region of proboscis receptacle, posterior to neck.

Male: (Based on 5 specimens) Trunk 12-18 (14) mm long, 490-835 (693) wide. Proboscis 805-1020 (871) long, 268-306 (298) wide. Neck 268-340 (315) long, 382- 510 (470) wide at base. Proboscis receptacle 1105-1785 (1334) long, 181-290 (220) wide; lemnisci (single measurement) 1540 long. Testes oval, tandem, not contiguous, in anterior third of trunk; anterior testis 470-840 (727) long, 248-425 (296) wide; posterior testis 603-1190 (828) long, 235-425 (344) wide. Cement glands, 4, elongated, tubular, begin immediately posterior to end of posterior testis, 4335-5610 (4972) long; Saefftigen’s pouch 918-2210 (1309) long. Genital pore terminal. Entire male system occupies about 85-90% of trunk length.

Female: (Based on 7 specimens) trunk 12-35 (19) mm long, 510-1020 (755) wide. Proboscis 740-1072 (871) long, 268-335 (306) wide. Neck 201-536 (358) long, 402-570 (486) wide at base. Proboscis receptacle 1206-1581 (1407) long, 227-325 (267) wide. Reproductive tract, uterine bell to genital pore, 972-1340 (1184). Genital pore subterminal. Eggs oval, external shell thick, ridged, 42.5-49.5 (46.0) long, 18.5- 23.0 (21.5) wide.

COMMENTS: Centrorhynchus viarius sp. n. conforms to the diagnosis of the genus given by Golvan (1956, 1960). In the key to the Neotropical species of Centrorhynchus of Lunaschi & Drago (2010) C. viarius falls within the group of species with a proboscis armature which has transitional hooks without lateral alate processes, namely C. albidus , C. polymorphus , C. crotophagicola and C. microcephalus . With a proboscis armature of 28-30 rows of 23-27 hooks C. viarius clusters with C. albidus and C. polymorphus each of which has up to 30 rows of hooks ( Lunaschi & Drago, 2010).

In terms of number of hooks per row C. viarius is closest to C. albidus , but differs in the number and type of hooks per row (8-9+4-5+12-13 compared with 7-8+3- 4+10). The hooks of C. viarius , are smaller and more variable in size, 18- 40 for hooks with roots and 10-30 for spiniform hooks, compared with 44 for hooks on the first third of the proboscis and 35 elsewhere for C. albidus ( Schmidt & Neiland, 1966) . None of the specimens of C. viarius examined in this study had hooks with reduced roots and manubria as figured by Schmidt & Neiland (1966). Centrorhynchus viarius further differs from C. albidus in the number of cement glands (4, as determined by transverse section, for C. viarius , 3 for C. albidus ) ( Schmidt & Neiland, 1966). Both species occur in Falconidae from Paraguay but C. viarius has been found in hawks, Buteo magnirostris, Buteogallus meridionalis , B. urubitinga and Parabuteo uncinctus while C. albidus has been reported from the plumbeous kite Ictinia plumbea (Gmelin, 1788) (see Golvan, 1956).

Of the species of Centrorhynchus also found in Paraguay C. viarius with a proboscis armature of 28-30 longitudinal rows of hooks is closest to C. pitangi , also with 28-30 rows of hooks. Centrorhynchus viarius differs from C. pitangi in the number of hooks per row (23-27 compared with 18-20) the form of the true hooks (all without manubria compared to hooks 1-4 with manubria and large simple roots and hooks 7-8 with manubria and reduced roots) as well as the number of spiniform hooks (7-8 compared to 12-13). Centrorhynchus viarius is a longer worm than C. pitangi and has shorter lemnisci, smaller testes and smaller eggs (Table 3). Centrorhynchus viarius can be differentiated from C. guira , a larger worm, in the number of hooks per row (23-27 compared with 18-19), the form of the manubria of the transitional hooks and the number of spiniform hooks (6 compared with 12-13). Centrorhynchus viarius can be differentiated from C. opimus by the number of rows of proboscis hooks (24 compared with 28-30) and the form of the true hooks (all without manubria compared to some with manubria). Centrorhynchus viarius further differs from C. geranoeti and C. millerae in the number of hooks per row (23-27 compared with 22-24 and 16-20 respectively) and the form of the true hooks (males and females having all true hooks with large simple hooks and transitional hooks compared with males having some true hooks with reduced hooks and no transitional hooks) and from C. simplex in the number of rows and hooks per row. Comparative measurements are given in Table 3. Centrorhynchus viarius differs from C. simplex in proboscis armature (28-30 longitudinal rows of 23-27 hooks compared with 22-24 longitudinal rows of 22-24 hooks).

Of the four species of Centrorhynchus known only from North America C. spinosus , with 30-32 longitudinal rows of 23-28 hooks, has a similar proboscis armature to that of C. viarius . Centrorhynchus spinosus , a much larger worm (females up to 60 mm long), can be differentiated from C. viarius by having 8-9 true hooks, no transitional hooks and 13-15 spiniform hooks in each row. The females of C. spinosus have two genital papillae.

KEY TO THE NEOTROPICAL SPECIES OF CENTRORHYNCHUS ; based on Lunaschi & Drago (2010).

1a Proboscis armature of 22-24 longitudinal rows of 24 hooks per row; 14 true hooks + 10 spines...................... C. simplex Meyer, 1932

1b Proboscis armature not as above.................................. 2

2a Proboscis armature with manubria on some true hooks................. 3

2b Proboscis armature without manubria on true hooks................... 6

3a Proboscis armature without transitional hooks. C. tumidulus (Rudolphi, 1819)

3b Proboscis armature with transitional hooks.......................... 4

4a Proboscis armature of 28-30 longitudinal rows of 18-20 hooks per row; 8-9+2+7-8........................................ C. pitangi sp. n.

4b Proboscis armature of less than 28 longitudinal rows of hooks............ 5

5a Proboscis armature of 24-28 longitudinal rows of 27-28 hooks per row; 16-17+1+10-11........................... C. giganteus Travassos, 1921

5b Proboscis armature of 24 longitudinal rows of 12-13 hooks; 8-9 true + transitional hooks + 3-4 spines................ C. opimus Travassos, 1921

6a Proboscis armature with transitional hooks in female only............... 7

6b Proboscis armature with transitional hooks in both male and female....... 8

7a Proboscis armature with 30-32 longitudinal rows of 16-20 hooks per row; male 6-7+9-14, female 5-6+3-4+10 transitionals with lateral processes.......................................... C. millerae sp. n.

7b Proboscis armature with 30 longitudinal rows of 22-24 hooks per row; male 11-12+9-10, female 8-10+3-4+9-10 transitionals without lateral processes...................................... C. geranoaeti sp. n.

8a Proboscis armature with transitional hooks with lateral processes......... 9

8b Proboscis armature with transitional hooks without lateral processes...... 10

9a Proboscis armature with 26-35 longitudinal rows of 22-27 hooks per row; 7-9+2+14-18................... C. kuntzi Schmidt & Neiland, 1966

9b Proboscis armature with 30-32 longitudinal rows of 18-19 hooks per row; 8-9+4+6........................ C. guira Lunaschi & Drago, 2010

10a Proboscis armature of more than 30 longitudinal rows of hooks.......... 11

10b Proboscis armature of up to 30 longitudinal rows of hooks.............. 12

11a Proboscis armature of 32-35 longitudinal rows of 15-17 hooks per row; 8-9+3+4-5.................. C. crotophagicola Schmidt & Neiland, 1966

11b Proboscis armature of 36-38 longitudinal rows of 17-18 rows of hooks; 9+3+5........................... C. microcephalus Bravo Hollis, 1947

12a Proboscis armature of 28-30 longitudinal rows of 20-22 hooks; 8+4+10........................................... C. albidus Meyer, 1932

12b Proboscis armature of 28-30 longitudinal rows of 23-27 hooks; 8-9+4- 5+12-13.......................................... C. viarius sp. n.