Neoechinorhynchus panucensis, Guillermo Salgado-Maldonado, 2013

Guillermo Salgado-Maldonado, 2013, Redescription of Neoechinorhynchus (Neoechinorhynchus) golvani Salgado-Maldonado, 1978 (Acanthocephala: Neoechinorhynchidae) and description of a new species from freshwater cichlids (Teleostei: Cichlidae) in Mexico, Parasitological Research 112, pp. 1891-1901 : 1896-1898

N. (N.) panucensis n. sp.

Type host: Herichthys labridens (Pellegrin) (Teleostei: Cichlidae ).

Other hosts: Amatitlania nigrofasciata (Günther) , Herichthys cyanoguttatus Baird and Girard (Teleostei: Cichlidae ).

Type locality: Río Atlapexco, Hidalgo State, Río Pánuco drainage, Mexico (21°00′53″N, 98°20′24″W), collected 27 March 1998.

Site: Intestine.

Prevalence and intensity: Six of 10 H. labridens (prevalence 60 %) were parasitized with 2, 2, 3, 5, 6, and 11 acanthocephalans (mean intensity, 4.8±3.4). A total of 29 acanthocephalans were collected. A. nigrofasciata : seven fish infected/24 fish examined (prevalence 29 %); parasitized with one, two, two, two, three, three, and five specimens; total, 18 acanthocephalans (mean intensity 2.6±1.2); Herichthys cyanoguttatum: two fish infected/12 fish examined (prevalence 16 %); with 3 and 7; total 10, acanthocephalans. All of them collected 27 March 1998.

Type material: Holotype CNHE 8378; allotype CNHE 8379; paratypes CNHE 8380-8381 and BMNH xxxx.x.x.x.

Etymology: The new species is named for the Río Pánuco, drainage basin in which it is found.

Description (Figs. 7–11)

General [Based on five mature specimens (one male, and four gravid females) and 14 juveniles (eight males, nine females)]. Eoacanthocephala, Neoechinorhynchida, Neoe chinorhynchidae, with characteristics of Neoechinorhynchus as diagnosed by Amin (2002). Body size medium, practically cylindrical, with almost parallel sides, rounded toward both extremities; posterior end curved ventrally. Sexual dimorphism present, with trunk larger in females than in males, other shared structures, proboscis, receptacle, and lemnisci also slightly larger in females than in males. Giant hypodermal nuclei of body wall not marked. Proboscis minute, cylindrical, with almost parallel sides. Proboscis hooks in three circles of six hooks each, those in adjoining circle alternating. Proboscis hooks gradually decrease in size posteriorly, hooks in anterior circle equal in size, all at same level. Anterior hooks largest, robust, strong, sharply curved; hooks in middle and basal circles are smaller than those in terminal series; hooks in posterior ring almost the same size than those of middle ring (Fig. 9). Anterior hooks rooted; roots simple, spoon shaped, posteriorly directed, shorter than blades; hooks in second and third circle have smaller discoid roots. Neck short, rather wider than long. Proboscis receptacle inserted at base of proboscis, single-walled, with triangular cephalic ganglion at its posterior end. Conspicuous para-receptacle structure present (Fig. 8). Lemnisci linguiform, near equal in length, longer than receptacle, two times as long as proboscis receptacle; often posteriorly festooned and some of them with a narrow posterior end. Genital pore terminal in males, subterminal in females placed just ventral to posterior extremity (Figs. 7, 10).

Measurements

Males (Measures of single mature male, holotype, are given first in square brackets; measurements of seven juveniles, range minimum–maximum, and mean in parentheses). Trunk [5,445] 1,150–2,930 (2,216)×[0.980] 0.122–0.792 (0,517). Proboscis [50] 40–50 (46.7)×[60] 48–60 (52.5); armed with six rows of three hooks each. Anterior proboscis hooks [30] 27–30 (28.8) long by [4] 3–5 (4) wide at base; middle hooks [20] 15–20 (17)×[3] 3 (3); basal hooks [16] 15–16 (15)×[3] 3 (3). Neck [15] 15–35 (23)×[60] 60–90 (65). Proboscis receptacle [275] 170–225 (196)×[110] 72–95 (77). Lemniscus [550] 187–400 (284)×[100] 50–70 (56); and [650] 187–470 (315)×[125] 50– 75 (56). Reproductive system in the only mature male holotype (Fig. 7) occupies almost two posterior thirds of body length, [3,712], in diameter almost fills the cavity. Testes ovoid elongate, contiguous, anterior testis [1,435] 255–653 (461)× [495] 225–465 (324); posterior testis [1,138] 212–643 (395)×[772] 245–504 (332). Vasa efferentia unite to form common duct before emptying into seminal vesicle, [350] 212–425 (275)×[142] 55– 150 (87). Cement gland voluminous, conspicuous, oblong, nearly the same diameter as testes, in broad contact with posterior testis, [990] 130–594 (341)×[643] 175–376 (275); well developed, conspicuous, round shaped reservoir [325] 100–277 (171)× [250] 65–227 (131). Saefftingen’s pouch [412] 150–346 (239) ×[82] 32–67 (45). In the holotype specimen, both the seminal vesicle and Saefftingen’s pouch invade the copulatory bursa. Copulatory bursa opens terminally.

Females (measurements of 4 gravid females paratypes, and of 4 juveniles). Trunk of gravid females 3,197–8,0 58 (6,083)× 782–1,0 19 (937); trunk of juveniles 1,450–2,385 (1,659)× 277–465 (372). Proboscis of gravid females 42–55 (48.5)× 48–63 (57.7); proboscis of juveniles 45–55 (48.7)×43–60 (52.7). Anterior hooks of gravid females 28–32 (30) long by 5 (5) wide at base, anterior hooks of juveniles 28–30 (29.5) long by 5 (5) wide at base; middle hooks of gravid females 16– 22 (18)×3 (3), middle hooks of juveniles 15–17 (16)×3 (3); basal hooks of gravid females 15–17 (16)× 3 (3); basal hooks of juveniles 14–17 (15)×3 (3). Neck of gravid females 12–35 (24)×62–85 (74); neck of juveniles 22–23 (22.5)×60–64 (62). Proboscis receptacle of gravid females 187–295 (229)×85–92 (90), proboscis receptacle of juveniles 150–205 (175) ×55–80 (63). Lemnisci of gravid females 307–550 (445) ×37–100 (74); and 307–675 (483)×37–85 (62); lemnisci of juveniles 245– 350 (275)×50 (50); and 237–400 (294)×42–55 (49). Total length of reproductive system from anterior margin of uterine bell to terminal genital pore in gravid females 500–570 (528), in juveniles 142–387 (267). Genital pore subterminal (Fig. 10). Eggs elliptical (Fig. 11), 30–35 (31.5)×8–13 (10).

Remarks

The new species N. (N.) panucensis stands out among the other species of Neoechinorhynchus because of the small size of its proboscis and anterior hooks. It can be typified by Figs. 7 – 11 Neoechinorhynchus (Neoechinorhynchus)

panucensis n. sp. from

Herichthys labridens Río Atlapexco, Hidalgo, Mexico. 7 Holotype male. 8 Anterior end of a paratype (CNHE xxx). 9 Proboscis. 10 Reproductive system of a paratype female. 11 Egg teased from the body cavity its medium size (males and females <20 mm long), diminute proboscis (<100 μ long), proboscis hooks which do not decrease gradually in size, hooks in the first ring all the same size and are the largest (<30 μ long) of the proboscis hooks (those in the second and third rings are smaller but similar in size), lemnisci are of the same size, with only slight differences between each, they are longer than the proboscis receptacle but still relatively short, and in males they are well separated from the anterior testis.

Eleven species of Neoechinorhynchus have been described from freshwater fishes in Central and South America, Neoechinorhynchus (Neoechinorhynchus) macronucletus Machado Filho 1954; Neoechinorhynchus (N e o e c hi no rh y nc hu s) b ut t n e r a e G o l v a n 195 6; Neoechinorhynchus (Neoechinorhynchus) paraguayensis M a c h a d o F i l h o 1 9 5 9; N e o e c h i n o r h y n c h u s (Neoechinorhynchus) Nickol and Thatcher 1971; Neoechinorhynchus (Neoechinorhynchus) curemai Noronha 1973 ; Neoechinorhynchus (Neoechinorhynchus) roseus Salgado-Maldonado 1978; Neoechinorhynchus (Neoechinorhynchus) pterodoridis Thatcher 1981 ; Neoechinorhynchus (Neoechinorhynchus) villoldi Vizcaíno 1992; Neoechinorhynchus (Neoechinorhynchus) pimelodi Brasil-Sato and Pavanelli 1998; Neoechinorhynchus (Neoechinorhynchus) chimalapasensis Salgado-Maldonado et al. 2010 ; Neoechinorhynchus (Neoechinorhynchus) brentnickoli Monks et al. 2011. Further differentiation between N. (N.) panucensis and these species is presented in the following key modified from Amin (2002) and based on original descriptions of the species (Machado Filho 1954, 1959; Golvan 1956; Nickol and Thatcher 1971; Noronha 1973, 1984; Salgado-Maldonado 1978; Nickol and Padilha 1979; Thatcher 1981; Vizcaíno 1992; Brasil-Sato and Pavanelli 1998; Martins et al. 2000; Salgado-Maldonado et al. 2010; Monks et al. 2011).