Prochristianella aciculata, Beveridge & Justine, 2010

Beveridge, Ian & Justine, Jean-Lou, 2010, Two new species of Prochristianella Dollfus, 1946 (Platyhelminthes, Cestoda) from the blue-spotted stingray, Neotrygon kuhlii (Müller & Henle, 1841) off New Caledonia, Zoosystema 32 (4), pp. 643-652 : 644-646

Prochristianella aciculata n. sp.

( Figs 1; 2)

TYPE MATERIAL. — New Caledonia, Nouméa, Îlot Maître (166°40’E, 22°34’S), from spiral valve of Neotrygon kuhlii (Müller & Henle, 1841) ( Rajiformes , Dasyatidae Jordan, 1888 ), 5.XI.2003, holotype ( JNC 958). — Same data, 19 paratypes ( MNHN JNC 957-958).

OTHER MATERIAL EXAMINED. — New Caledonia, off Nouméa, X.1998, 1 specimen ( MNHN JNC 1627).

ETYMOLOGY. — The specific name relates to the aciculate nature of the larger hooks of the principal rows of the metabasal armature.

DESCRIPTION

Small cestodes, mature specimens 3.0-5.0 (3.5, n = 7) long with 7-9 (8, n = 9) segments, gravid specimens 3.5-6.5 (4.3, n = 7) long with 8-11 (9, n = 8) segments. Scolex acraspedote, surface smooth, 640-1050 (788, n = 10) long; width in region of pars bulbosa 140-190 (160, n = 10); 2 sub-circular bothria, pars bothrialis 190-240 (218, n = 10), bothrial width 190-200 (195, n = 4); pars vaginalis 390-740 (515, n = 10); sheaths sinuous; prominent transverse striations present in pars vaginalis of some specimens; bulbs elongate, extending to posterior margin of scolex or in some specimens extending slightly into pars proliferans scolecis; bulbs 250-340 (279, n = 10) long, 40-50 (45, n = 10) wide; bulb ratio 5.00-7.75 (6.26, n = 10); retractor muscle originates at base of bulb, origin surrounded by small number of gland cells; pre-bulbar organ present.

Partially everted tentacles up to 300 long, with prominent basal swelling; diameter in basal region 20-28 (25, n = 10), in metabasal region 15-20 (17, n = 10); hooks hollow. Basal armature: first 2-3 rows of hooks enlarged, falcate, 7-11 (10.7, n = 5) long, base 5-6 (5.4, n = 5); next 6-7 rows of hooks smaller, sagittate on antibothrial surface, tending to uncinate on bothrial surface, 3-5 (4.2, n = 10) long, base 1-4 (2, n = 10); rows 8-12 with elongate, recurved hooks on antibothrial surface changing to sagittate hooks on internal and external surfaces and then to bill hooks on bothrial surface, rows originating on antibothrial surface, terminating on bothrial surface; elongate, recurved hooks 3-6 (4.7, n = 10) long, base 0.5-1.0 (0.85, n = 10); bill hooks 3.5-5.0 (4.1) long, base 0.5-1.0 (0.9, n = 10) long; transition to metabasal armature occurs at about row 15.

Metabasal armature heteroacanthous, typical; hook rows begin on antibothrial surface of tentacle, terminate on bothrial surface. Distinct space between hooks 1 and 1’ on antibothrial surface of tentacle. Hooks 1(1’) small, almost linear with tiny, hooked extremity, 5-6 (5.5, n = 5) long, base 3.5- 4.5 (4.2, n = 5), not clearly visible in many views of tentacle; hooks 2(2’) robust, uncinate, 7-10 (8.7, n = 10) long, base 3-5 (4.3, n = 10) long; hooks 3(3’) slender, falcate, 10-15 (12.4, n = 10) long, base 3-4 (3.5, n = 10) long; hooks 4(4’) slender falcate, 10-16 (13.6, n = 10) long, base 3-5 (4.7, n = 10) long; hooks 5(5’) much shorter than hooks 4(4’) and 6(6’), slender, 4.5-8.9 (6.6, n = 10) long, base 0.5-2.0 (1.6, n = 10) long; hooks 6(6’) larger, slender falcate, 9-14 (11.7, n = 10) long, base 2-5 (2.9, n = 10) long; hooks 7(7’) small spiniform, 1.5- 5.5 (3.8, n = 10) long, base 0.5-2.0 (1.1, n = 10); hooks 8(8’)-10(10’), tiny, spiniform, 1-3 (2, n = 10) long, base 0.5-1.0 (0.6, n = 10) long.

Mature segments acraspedote, elongate, 750-1340 (950, n = 5) long, 160-200 (179, n = 5) wide; length/ width ratio 4.63-7.88 (5.34, n = 5); genital pore irregularly alternating in posterior third of segment, 250-580 (364, n = 5) from posterior end. Cirrus sac sub-globular, 70-100 (82, n = 3) in diameter, cirrus unarmed, coiled within cirrus sac; testes 40- 50 (45, n = 5) per segment arranged in 2 columns anterior to ovary; 5-7 (6, n = 5) testes posterior to genital pore, 14-19 (17, n = 7) anterior to genital pore, 21-25 (22, n = 5) on anti-poral side of segment; testis diameter 40-55 (49, n = 10). Ovary at posterior extremity of segment, with 4 lobes, each lobe 150-280 (172, n = 5) long, 40-60 (48, n = 5) wide, with multiple lobules; Mehlis’ gland present between ovarian lobes; vitelline follicles circummedullary, 10-25 (19, n = 10) in diameter; uterus tubular, median, extending to anterior extremity of segment; uterine pore absent. Gravid segments 950-2030 (1268, n = 5) long, 390-570 (508, n = 5) wide; gravid uterus entirely filling medulla; eggs immature.