Acleotrema spiculare ( Yamaguti, 1968 ) Domingues & Boeger, 2007

Acleotrema spiculare ( Yamaguti, 1968) Domingues & Boeger, 2007 View in CoL

Syn. Diplectanum spiculare Yamaguti, 1968

Figs 5A–H View FIGURE 5 , 6E View FIGURE 6

Host. Kyphosus vaigiensis (Quoy & Gaimard, 1825) ( Centrarchiformes : Kyphosidae ), brassy chub.

Locality. Off Puerto Santa Rosa (6°52’S, 79°55’W), Lambayeque, Peru, South America GoogleMaps .

Deposited material. 4 voucher specimens (MUSM 5517a–d) from K. vaigiensis .

Site in host. Gill filaments.

Redescription. Based on 4 specimens: 2 mounted in Gomori’s trichrome and 2 mounted in Hoyer’s medium: Body elongate, fusiform, 520–992 (814; n = 4) µ long; greatest width 106–299 (203; n = 4) usually at level of MCO. Scales not observed. Cephalic region narrow, with one terminal and 2 bilateral inconspicuous cephalic lobes; 3 bilateral pairs of conspicuous head organs; unicellular cephalic glands not observed. Two pairs of eye-spots present, equidistant; accessory chromatic granules absent ( Fig. 5A View FIGURE 5 ). Mouth subterminal; pharynx spherical, 31–39 (35; n = 2) in diameter; esophagus absent; intestinal caeca unbranched, extending from anterior to near posterior end of trunk, not confluent posteriorly. Haptor differentiated from body proper, laterally expanded, 68–113 (88; n = 3) long, 182–319 (234; n = 3) wide. Anchors dissimilar ( Fig. 5B–C View FIGURE 5 ). Ventral anchor 57–69 (64; n = 3) long; elongate superficial root; well-elongate deep root, almost twice as long as superficial root, medially expanded; curved shaft; and recurved point; point surpassing level of tip of superficial root; base 3–5 (4; n = 3) wide. Dorsal anchor 37–42 (39; n = 3) long, with inconspicuous superficial root, short and subquadrangular deep root, evenly curved shaft, and short point; point surpassing level of tip of superficial root; base 11–15 (13; n = 3) wide. Ventral bar 130–258 (189; n = 4) long, elongate, broadly W-shaped, with mid-ventral longitudinal groove, tapered ends posteriorly directed ( Fig. 5D View FIGURE 5 ). Dorsal bars 62–105 (83; n = 4) long, curved, with spatulate medial end ( Fig. 5E View FIGURE 5 ). Fourteen similar hooks, 10–11 (10; n = 3) long, each with depressed obtuse thumb, slender and slightly curved shank, and short point; filamentous hook (FH) loop about shank length; hook pair 1 at level of ventral bar; hook pair 5 at level of ventral anchor base, others submarginal pairs on lateral haptoral lobes ( Fig. 5F View FIGURE 5 ). Squamodiscs, similar, each 31–87 (71; n = 3) long; 146–287 (214; n = 3) wide, with 42–48 (45; n = 3) concentric rows; dumbbell-shaped rodlets ( Fig. 5G View FIGURE 5 ). Genital atrium not observed. MCO sclerotized, tubular, elongate, 45–55 (48; n = 3) long, surrounded by thorny sheath; MCO surrounded by weakly sclerotized sac, spatulate distally with lateral folds ( Fig. 5H View FIGURE 5 ). Testis ovate, 40 (40; n = 1) long, 36 (36; n = 1) long; vas deferens, seminal vesicle, prostatic reservoir, prostatic glands not observed. Ovary elongate, 82 (82; n = 1) long, 56 (56; n = 1) wide, looping dorsoventrally right intestinal caeca; oviduct, oötype uterus not observed. Vagina, seminal receptacle not observed. Vitelline follicles dense, extending from posterior level of pharynx to posterior end of trunk, absent in regions of reproductive organs. Eggs not observed.

Remarks. This species was originally placed in Diplectanum Diesing, 1858 by Yamaguti (1968), based on specimens collected on K. cinerascens in Hawaii and later transferred to Acleotrema by Domingues & Boeger (2007). According to Domingues & Boeger (2007), this species is characterized by its distinctive spicule-shaped cirrus. The redescription presented in this study complements the original description by providing additional details on the MCO, anchors, bars and hooks. Additionally, we provided the first whole-mount drawing of A. spiculare , along with morphometric data. This finding represents a new geographical record for this diplectanid.