Callorhynchocotyle amatoi Boeger, Kritsky & Pereira, 1989

Vaughan, David & Christison, Kevin, 2012, Towards addressing the current state of confusion within the Hexabothriidae Price, 1942 (1908): Callorhynchocotyle Suriano & Incorvaia, 1982 (Monogenea: Hexabothriidae) re-visited, with the preliminary evaluation of novel parameters for measuring haptoral armature of hexabothriids, Zootaxa 3229, pp. 1-34 : 22-25

Callorhynchocotyle amatoi Boeger, Kritsky & Pereira, 1989

( Figs 9 , 10 , Tables 1, 2)

Synonyms: Squalonchocotyle callorhynchi Manter, 1955 (in part); Erpocotyle callorhynchi Dillon & Hargis, 1968 (in part).

Type host. Callorhinchus milii (Bory de Saint-Vincent) ( Callorhynchidae , Holocephali).

Type locality. Coast of New Zealand.

Additional locality. Off Queenscliff, Victoria, Australia (present study).

Site on host. Gills.

Material examined. USNPC 0 71197.02 paratypes M 1015-16 and 17; USNPC 0 80983.00 vouchers M1523-3, 4 and 5; SAMCTA 29467 (2 whole mounts and 2 haptor digest vouchers); AHC 29749 (1 whole mount voucher) and AHC 29750 (1 haptor digest voucher).

Redescription. Total body length ( Fig. 9 A) 6892 ± 359.1(6625–7300, n = 3), maximum body width 1349 ± 114.4(1254–1476, n = 3). Oral sucker internally papillate, diameter 366 ± 35.5(338–406, n = 3). Pharynx 109 ± 9.6(103–120, n = 3) long, 91 ± 4.0(88–96, n = 3) wide ( Fig. 9 A). Branched intestinal caeca unite posterior to testes and extend into the haptor ( Fig 9 A). Asymmetrical haptor 2750 ± 534.1(2200–3267, n = 3) long, 1138 ± 282.3(937–1460, n = 3) wide with 3 paired sucker sclerite complexes. Haptoral suckers papillate ( Fig. 9 A).

Sucker sclerites of complex 3 ( Fig. 10 A): circumference length 1092 ± 96.4(989–1181, n = 4); total length 428 ± 12.0(415–436, n = 4); total diameter 319 ± 15.9(304–336, n = 4); width 71 ± 2.8(68–74, n = 4); shaft length 421 ± 13.3(407–433, n = 4); inner diameter 249 ± 14.2(237–265, n = 4); aperture angle 40° ± 5.9(35°–46°, n = 4); aperture 191 ± 31.5(158–221, n = 4); hook-side curve length 77 ± 1.8(75–79, n = 4) and shaft-side curve length 130 ± 10.7(118–138, n = 4). Complex 3 sucker-sclerite hook length 138 ± 5.2(134–144, n = 4); hook curve length 18 ± 2.8(15–21, n = 4); aperture 109 ± 4.4(106–114, n = 4) and base width 40 ± 0.4(39–40, n = 4).

Sucker sclerites of complex 2 ( Fig. 10 B): circumference length 1111 ± 98.3(998–1172, n = 4); total length 451 ± 37.1(410–481, n = 4); total diameter 336 ± 32.4(299–357, n = 4); width 73 ± 3.7(69–76, n = 4); shaft length 451 ± 35.8(411–479, n = 4); inner diameter 264 ± 28.2(232–282, n = 4); aperture angle 48° ± 15.1(31°–59°, n = 4); aperture 248 ± 97.1(137–311, n = 4); hook-side curve length 80 ± 3.6(78–84, n = 4) and shaft-side curve length 116 ± 20.6(99–139, n = 4). Complex 2 sucker-sclerite hook length 126 ± 7.7(120–135, n = 4); hook curve length 18 ± 0.3(17–18, n = 4); aperture 102 ± 7.1(96–110, n = 4) and base width 37 ± 3.2(35–41, n = 4).

Sucker sclerites of complex 1 ( Fig. 10 C) smaller than similarly sized sucker sclerites of complex 2 and 3 with circumference length 863 ± 27.8(837–892, n = 4); total length 401 ± 69.9(323–458, n = 4); total diameter 257 ± 17.0(237–267, n = 4); width 43 ± 4.0(38–46, n = 4); shaft length 402 ± 66.2(328–456, n = 4); inner diameter 217 ± 21.6(192–232, n = 4); aperture 280 ± 130.1(142–401, n = 4); hook-side curve length 61 ± 10.3(49–69, n = 4); and shaft-side curve length 86 ± 20.9(62–99, n = 4). Complex 1 sucker-sclerite hook length 56 ± 0.5(56–57, n = 4); hook curve length 10 ± 0.7(10–11, n = 4); aperture 47 ± 0.7(46–48, n = 4) and base-width 15 ± 0.6(15–16, n = 4).

Dorsal haptoral appendix 1016 ± 223.9(810–1254, n = 3) long, 434 ± 18.3(413 – 444, n = 3) wide. Terminal suckers of appendix 287 ± 28.0(257–330, n = 6) long, 142 ± 6.5(135–154, n = 3) wide. Single pair of hamuli present before terminal suckers.

Hamulus ( Figs. 10 D) total length 54 ± 1.6(53–56, n = 4); hook point length 15 ± 0.3(15–16, n = 4); hook shank length 16 ± 0.8(15–17, n = 4) total diameter 29 ± 0.8(28–30, n = 4); hook distal point width 3 ± 0.2, n = 4; outer aperture angle 17° ± 0.3(16°–17°, n = 4); aperture 102 ± 4.5(98–107, n = 4); hook shank base width 6 ± 0.6(5–7, n = 4); inner root-shaft length 42 ± 1.3(40–44, n = 4); outer root-shaft length 44 ± 2.9(41–49, n = 4); root base angle 105° ± 10.7(93°–118°, n = 4), and root base width 23 ± 1.4(20–24, n = 4).

Testes irregular in shape, 103 ± 7.7(94–109, n = 8) in number; 86 ± 9.9(74–103, n = 17) wide. Vas deferens sinuous, surrounded by small gland cells along the majority of its length ( Fig. 9 C). Vas deferens loop proximal to entrance into cirrus absent in some specimens. Unarmed muscular cirrus total length 429, n = 1; maximum width 70, n = 1; distal bulb length 85, n = 1, and distal bulb width 85, n = 1.

Ovary (dextral = 2, sinistral = 1) 763 ± 59.1(694–799, n = 3) long, anteriorly branched, coiled posteriorly, ascending to oviduct, branching to sac-like, reduced seminal receptacle ( Fig. 9 C). Ootype smooth, leading to uterus, dorsal to ovary, ventral to vas deferens ( Fig. 9 C). Ovate eggs connected by tendrils at each pole. Eggs (in uterus) 163 ± 16.1(151–186, n = 4) long, 82 ± 12.55(70–100, n = 4) wide. Parallel vaginal ducts with glandulomuscular distal portion and thin-walled proximal portion. Ventral vaginal pores muscular, lateral to median portion of cirrus ( Fig. 9 B). Follicular vitellarium originates posterior to vaginal pores. Excretory pores not observed.

Remarks. Specimens collected off Queenscliff, Victoria, Australia represent a new locality record for C. amatoi . Boeger et al. (1989) erected C. amatoi for all the New Zealand material of C. callorhynchi from Callorhinchus milii , separating C. amatoi from C. callorhynchi on sucker sclerite morphology alone. Sucker sclerites of complex 2 and 3 are smaller than those of C. marplatensis and C. callorhynchi in total and hook-side curve lengths. Suckersclerite shaft lengths of complex 2 are shorter than those of C. callorhynchi and C. marplatensis . Sucker-sclerite shaft length and total and inner diameters of complex 3 are shorter than those of C. marplatensis and C. callorhynchi . The sucker-sclerite hook of complex 2 and 3 are shorter in length than both those of C. marplatensis and C. callorhynchi . The base widths of complex 2 and 3 sucker-sclerite hooks are narrower than those of C. callorhynchi .

Callorhynchocotyle amatoi is differentiated from C. callorhynchi by the shape of the hamulus. The hamulus of C. amatoi is shorter in total and hamulus-hook shank lengths, narrower in total, hamulus-hook shank base and base widths. The inner root-shaft length is greater than that of C. callorhynchi . Hamulus-hook point length is longer and the hamulus-hook distal point width is narrower than that of C. marplatensis . Callorhynchocotyle amatoi is differentiated from C. marplatensis in possessing a papillate oral and papillate haptoral suckers and is only found on the gills of Callorhinchus milii .

Beverley-Burton & Chisholm (1990) presented a simple key to the Callorhynchocotyle species wherein C. amatoi is separated from C. callorhynchi by the presence of an expanded proximal portion of the cirrus complex, which is absent in C. callorhynchi . The additional voucher material collected and examined for the present study has revealed that C. callorhynchi also possesses an expansion of the proximal cirrus portion, and therefore this character is invalid as a diagnostic character.

Figures

FIGURE 9. Callorhynchocotyle amatoi. A. Whole mount. B. Enlarged anterior section of whole mount. C. Enlarged mid-section of whole mount. Scale bars = 1000 µm.

FIGURE 10. Callorhynchocotyle amatoi sucker sclerites of complexes 1 (A), 2 (B) and 3 (C), and hamulus (D). Scale bars: A = 260 µm, B, C = 340 µm, D = 50 µm.