Dactylogyrus pisolabrae, Cloutman & McAllister & Robison, 2020

Cloutman, Donald G., McAllister, Chris T. & Robison, Henry W., 2020, Dactylogyrus Pisolabrae N. Sp. (Monogenoidea: Dactylogyridae) Parasitizing The Pealip Redhorse, Moxostoma Pisolabrum (Teleostei: Catostomidae), From Oklahoma, U. S. A., Journal of Parasitology (J. Parasitol.) 106 (1), pp. 53-55 : 54

Dactylogyrus pisolabrae n. sp.

( Figs. 1–10 )

Description: With characters of the genus as emended by Mizelle and McDougal (1970). Body with thin tegument; 473 (440–520, 4) long, greatest width 101 (100–104, 4). Two pairs of anterior cephalic lobes. Head organs not observed. Two pairs of eyes, equal in size and approximately the same distance apart. Pharynx circular, diameter 26 (24–28, 4). Peduncle 16 (10–20, 4) long, 64 (55–70, 4) wide. Haptor 74 (70–76, 4) long, 88 (76–98, 4) wide. Dorsal anchor composed of solid base with short deep root, elongate superficial root, solid elongate shaft curving to a sharp point; 35 (35–36, 4) long; greatest width of base 16 (14–17, 4); deep root 3 (3–4, 4) long; superficial root 13 (12–14, 4) long. Ventral anchor (4A) 6 (5–6, 3) long. Dorsal bar gently curved with knobs on each end; 32 (30–36, 4) long. Ventral bar a crooked rod pointed at both ends; 16 (15–16, 4) long. Fourteen hooks (7 pairs), similar in shape. Each hook composed of solid base, solid slender shaft, sickle-shaped termination provided with opposable piece. Hook lengths: nos. 1, 17 (13– 19, 4); 2, 28 (26–30, 4); 3, 31 (28–32, 4); 4, 30 (28–33, 4); 5, 22 (21– 22, 4); 6, 21 (19–22, 4); 7, 23 (21–24, 4). Copulatory complex composed of male copulatory organ and non-articulated accessory piece. Male copulatory organ with large base bearing robust, tubular, sickle-shaped shaft; total length 38 (36–40, 4) long. Accessory piece solid, biramous; medial process a triangular blade at approximately midlength; distal ramus hooked at the tip to a sharp point; proximal portion of accessory piece with 2 flattened, wing-like projections opposite each other; total length 38 (36–40, 4). Vagina sclerotized. Vitellaria distributed from pharynx to haptor.

Taxonomic summary

Synonym: Dactylogyrus sp. ( McAllister et al., 2017).

Type host: Moxostoma pisolabrum Trautman and Martin, Pealip Redhorse.

Type locality: Oklahoma : Cherokee County, Illinois River , Arkansas River System (35°56 ′ 34.4724 ′′ N, 94°54 ′ 44.2152 ′′ W) .

Materials deposited: Holotype, HWML 216232 ; 3 paratypes, HWML 216233 .

Site of infection: Gills.

Prevalence, mean intensity ± standard deviation, and range of infection: 1 of 2 infected (prevalence 50%, mean intensity 4.0 ± 0.0, range ¼ 4).

ZooBank registration: urn:lsid:zoobank.org:act:E5C4B7D1-78F3-4ED3-AA9C-B957356D2163

Etymology: Dactylogyrus pisolabrae is named after its only known host, Moxostoma pisolabrum .

Remarks

Dactylogyrus pisolabrae is morphologically most similar to Dactylogyrus apos Mueller, 1938 ; Dactylogyrus atripinnei Timmons and Rogers, 1977 ; Dactylogyrus duquesnei Mueller, 1938 ; and Dactylogyrus niger Rogers and Mizelle, 1966 , all parasitizing some species of suckers ( Catostomidae ) ( Hoffman, 1999), by possessing a robust, sickle-shaped male copulatory organ ( Mueller, 1938; Rogers and Mizelle, 1966; Timmons and Rogers, 1977). It differs from these and all other species of North American Dactylogyrus by possessing 2 unique flattened, winglike projections opposite each other on the proximal portion of the accessory piece.

Figures

Figures 1–10. Line drawings of Dactylogyrus pisolabrae n. sp. (drawings are of the holotype, HWML 216232, unless otherwise specified). (1) Whole mount (ventral). (2) Dorsal anchor. (3) Dorsal bar. (4) Ventral anchor (4A). (5) Ventral bar. (6) Hook. (7) Male copulatory organ. (8) Accessory piece. (9) Male copulatory organ (HWML 216233). (10) Accessory piece (HWML 216233).