Centrorhynchus geranoaeti, 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 : 181-186

Centrorhynchus geranoaeti n. sp. Figs 13-19

MATERIAL EXAMINED: MNHG-INVE-82718; holotype, male, from the small intestine of Geranoeatus melanoleucos (Gmelin, 1788); Paraguay, Aquidaban, 12.10.1988 . – MNHG-INVE- 82719; paratype (allotype), female, from the small intestine of Geranoeatus melanoleucos (Gmelin, 1788); Paraguay, Aquidaban, 12.10.1988 . – MNHG-INVE-38386; paratypes, male, 1 piece male, 2 females, 1 juvenile female, all from the small intestine of Geranoeatus melanoleucos (Gmelin, 1788); Paraguay, Aquidaban, 12.10.1988 .

ETYMOLOGY: The species name is taken from the genus name of the host.

DESCRIPTION

General: (based on 2 males, 3 females, and 1 juvenile female) Trunk spineless, elongated; dilated anteriorly in region of testes in male, more or less cylindrical in female terminating in a digitiform process. Neck shorter than broad. Proboscis in 2 parts, slightly wider at base, with constriction anterior to insertion of proboscis receptacle, at about half way between apex and base of proboscis. Proboscis armature 30 rows 20-22 hooks, showing sexual dimorphism. Males: first 7-8 hooks in each longitudinal row with large simple roots, blades hooks 1-6/7 45-50 long, blades hooks 7/8 25 long; next 1-2 hooks with laterally extending shorter roots, blades 10-15 long; posterior 9-11 hooks spiniform, inserted on posterior part of proboscis, blades 10-20 long. Females: first 7-8 hooks with large simple roots, blades 1-7/8, 45-50 long, blades 7/8, 30 long; next 3-4 transitional hooks, blades 25 long; posterior 10-11 hooks spiniform, inserted on posterior part of proboscis, blades 10-30 long. Neck spineless, shorter than broad. Proboscis receptacle double walled. Lemnisci tubular, inserted at TABLE 3. Comparative measurements of Centrorhynchus albidus and selected other species of Centrorhynchus , reported from South America, including species from this study; data from Travassos, 1926, Petrochenko, 1958, Schmidt & Neiland, 1966, Lunaschi & Drago, 2010.

C. albidus C. C. C. guira C. millerae C. pitangi C. C. viarius C. tumidulus geranoaeti giganteus polymorphus

Argentina Paraguay

Males young male

Trunklengthmm 12 15 12.5 26.1- 30.9 30 13 9-11 6.5 12-18 15-24

Proboscis length 928-1250 1005 1870 790-970 805 650 1005-1020 670-880 804-1020

Neck length 18 235 30-68 235-360 221 268-402 268-306

width 372 636 410-510 470-510 370 670-735 382-510

Proboscisreceptaclelength 1160-1250 1410 1400-1600 1200 1200 1307-1360 800-1000 1105-1785 1000-1160

Lemnisci length 1460-2500 1360 5200 1940-2340 2211 1250 2800 1200-2000 1540 1300-2300

Anterior testis length 1000-568 502 300 1060-1200 1088 536 1105-1700 250 470-480 570

width 278 402 250 540-630 476-595 402 476-731 200 248-425 670

Posterior testis length 670 1110-1290 1139-1156 536 1105-1870 603-1190

width 335 514-660 527-697 375 510-782 235-425

Cementglandslengthmm 6.7 7.0 18.0-18.7 8.8 5.1 2.5-3.0 4.3-5.6 10.0-14.0

Saefftigen’s pouch length 1400 1000 2710-2970 2380-3400 1300 1200 1000 918-2210 1100-2300

Females mature

female

Trunklengthmm 16 21-22 37-55 38.8-50.4 50-55 25-35 16-19 9 12-35 15-37 Reproductive tract length 1206 2630 2145 900-2250 2000 972-1340

Proboscislength 1250 1105-1240 920-1000 805 850-900 804-1020 740-1072 Proboscisreceptaclelength 1250 1530-1700 1690-1770 1700 1226-1810 1394-1615 1206-1581

Lemnisci length 2500 1800-2710 2211 1445-1700 2200 1005-1335

Egglength 42 49.5-56.0 56.0 53-64 46-53 49.5-56.0 56-66.5 44-50 42.5-49.5 53-56

width 20 23-29.5 28-32 24-29 23-30 23.0-29.5 26.5-32.5 22-30 18.5-23.0 21

FIGS 5-12

Centrorhynchus guira Lunaschi & Drago, 2010 . (5) Male anterior end. (6) Male proboscis showing armature. (7) Egg. (8) Male proboscis hooks, showing part of longitudinal row of true hooks numbers 4, 5, 6, 7 and 8 and 2 rows of 3 transitional hooks numbers 9, 10 11 and 9, 10, 11, 12 respectively. (9) Male posterior end. (10) Female posterior end showing bulbous shape and reproductive tract. (11) Male proboscis hooks showing longitudinal rows of 6 spiniform hooks. (12) Female proboscis, longitudinal rows of 4 and 5 transitional hooks showing manubria from differing orientations. Scale bars: 5, 9, 10, 1 mm; 6, 100 µm; 7, 8, 11, 12, 25 µm.

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

Male: (based on 2 specimens) Trunk 15 mm long, 1550 at widest part. Proboscis 1005 long, 335 wide. Neck 235 long, 635 wide at base. Proboscis receptacle 1410 long, 340 wide; lemnisci 1360 long. Testes oval, tandem, not contiguous, in anterior third of trunk; anterior testis 502 long, 402 wide; posterior testis 670 long, 335 wide. Cement glands, 3, elongated, tubular, begin immediately posterior to end of posterior testis, 6700 long; Saefftigen’s pouch 1400 long. Genital pore terminal. Entire male system occupies about 88% trunk length.

Female: (Based on 3 specimens) Trunk 21, 22 mm long, 765, 940 wide. Proboscis 1105, 1240 long, 302, 425 wide. Neck 155, 235 long, 535, 605 wide at base. Proboscis receptacle 1530, 1700 long, 255, 325 wide. Lemnisci concealed by eggs. Reproductive tract, uterine bell to genital pore, 1206 long. Posterior end with digitiform papilla, genital pore subterminal. Eggs oval, external shell thick, ridged, 49.5- 56.0 (52.8) long, 23.0-29.5 (25.6) wide.

COMMENTS: Centrorhynchus geranoaeti n. sp. conforms to the diagnosis of the genus given by Golvan (1956, 1960). Centrorhynchus geranoaeti differs from all other species of Centrorhynchus in that the female has typical transitional hooks with anteriorly extending manubria but the male does not. In males the anterior true hooks have large simple roots and the posterior ones short laterally extending roots. In the key to the Neotropical species of Centrorhynchus by Lunaschi & Drago (2010) C. geranoaeti with 30 longitudinal rows of 22-24 hooks, the transitionals with lateral alate processes, falls closest to C. guira , with 32 rows of 18-19 hooks, also with transitionals with lateral alate processes. Centrorhynchus geranoaeti can be further differentiated from C. guira , in having fewer, smaller, transitional hooks (2-3, 10-20 long, compared with 4-5, 19-33 long) and more spiniform hooks (9-11 compared with 6-7) in each longitudinal row. Centrorhynchus geranoaeti is a smaller worm than C. guira , with a longer proboscis, lemnisci not extending posteriorly beyond the proboscis receptacle, smaller testes, shorter cement glands, Saefftigen’s pouch and female reproductive tract. The female trunk is more or less cylindrical, terminating in a digitiform process in C. geranoaeti and swollen posteriorly in C. guira . See Table 3 for comparative measurements.

Centrorhynchus geranoaeti with a proboscis armature of 30 rows of 22-24 hooks per row is also near to C. albidus and C. polymorphus , both having 28-30 rows of hooks and nearest to C. albidus that has 20-22 hooks per row ( Schmidt & Neiland, 1966). Lunaschi & Drago (2010) interpret the proboscis armature of C. albidus , from figure 5 of Schmidt & Neiland (1966), as being up to 30 rows of 8 + 4 + 10 hooks per row. The descriptive text states “first 7 hooks in each row with well developed root, next hook with reduced root, next 13 or 14 hooks rootless” ( Schmidt & Neiland, 1966). A careful study of figure 5, however, shows 8 hooks with true roots, the next with a reduced root and manubrium, then 3 with manubrium only and the last 10 rootless spines. Using this latter interpretation C. geranoaeti and C. albidus further differ in the number and form of each type of hook in each row (for males 8-10 hooks with large roots + 1-2 hooks with reduced roots + 9-10 spiniform hooks, compared with 7-8 hooks

FIGS 13-19

Centrorhynchus geranoaeti sp. n. (13) Male. (14) Female proboscis, showing armature. (15) Egg. (16) Female proboscis hooks, longitudinal row showing true hooks 8, 9, 10 and 3 transitional hooks. (17) Female posterior end. (18) Female posterior end showing reproductive tract, trunk contracted, posterior digitiform process inverted. (19) Male proboscis hooks, showing examples of a true hook with a large simple root and true hooks with reduced roots. Scale bars: 13, 1 mm; 14, 200 µm; 15, 16, 19, 25 µm 17, 500 µm; 18, 400 µm.

with large roots + 1 hook with reduced root and manubrium + 3 transitional hooks + 9-11 spiniform hooks). Centrorhynchus geranoaeti has smaller testes and larger eggs than C. albidus (Table 3).

Centrorhynchus geranoaeti further differs from C. polymorphus in the number of hooks per row (22-24 compared with 17), body shape (cylindrical not claviform) and length of proboscis, proboscis receptacle, cement glands and testis size (Table 3). Dimitrova & Gibson (2005) suggested that shape and size of the body and proboscis of C. polymorphus better fits the generic diagnosis of Sphaerirostris than of Centrorhynchus (see Golvan, 1956, 1960).

Centrorhynchus simplex Meyer, 1932 , from Brazil was described only from juvenile forms encysted in the body cavity of a snake. The identity of the host is uncertain although the name given in the text, Coluber olivaceus, may be Liophis poecilogyrus (Wied-Neuwied, 1825). Centrorhynchus simplex can be distinguished from C. geranoaeti by the proboscis armature of 22-24 longitudinal rows of 24 hooks ( Petrochenko, 1958).

Six species of Centrorhynchus are found in North America ( Richardson & Nickol, 1995). Centrorhynchus kuntzi has also been recorded from Nicaragua and C. microcephalus from Mexico, both therefore being included in the key to the Neotropical species of Centrorhynchus . Of the remaining four species, C. californicus Millzner, 1924 , C. conspectus Van Cleave & Pratt, 1940 and C. robustus Richardson & Nickol, 1995 have been reported only from the United States of America ( Richardson & Nickol, 1995) and C. spinosus (Kaiser, 1893) from the United States and the Galapogos Islands (Van Cleave, 1924, 1940; Richardson & Nickol, 1995). Centrorhynchus californicus , C. conspectus and C. robustus can be distinguished from C. geranoaeti by their proboscis armature, having neither 30 longitudinal rows of hooks nor 10-12 true hooks, nor any transitional hooks in either male or female in each longitudinal row. Centrorhynchus spinosus is a larger worm than C. geranoaeti (male 30-45 mm compared with 15 mm), although with 32 rows of hooks it has a similar proboscis armature. However C. spinosus has no transitional hooks in either male or female and more spiniform hooks than C. geranoaeti (14-15 compared with 9-11) per row and the hooks of C. spinosus are larger than those of C. geranoaeti (48-60 compared with 10-50).