Callorhynchocotyle sagamiensis Kitamura, Ogawa, Taniuchi & Hirose, 2006

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 : 26-29

Callorhynchocotyle sagamiensis Kitamura, Ogawa, Taniuchi & Hirose, 2006

( Fig. 11 , Tables 1, 2)

Type host. Chimaera phantasma ( Jordan & Snyder) ( Chimaeridae , Holocephali). Type locality. Off Odawara, Sagami Bay, Kanagawa Pref. (35°15’N, 139°15’E), Japan. Additional localities. Off Enoshima, Sagami Bay, Kanagawa Pref. (35°15’N, 139°30’E), Japan; Tokyo Bay, Japan (present study).

Site on host. Gills.

Material examined. SAMCTA 29468 (1 whole mount voucher and 1 haptor digest voucher)

Supplemental information. Total body length 4533, n = 1, maximum body width 1111, n = 1. Oral sucker internally papillate, diameter 417, n = 1. Pharynx 78, n = 1 long, 67, n = 1 wide. Branched intestinal caeca unite posterior to testes and extend into the haptor. Asymmetrical haptor 2300, n = 1 long, 1143, n = 1 wide with 3 paired sucker sclerite complexes. Haptoral suckers papillate.

Sucker sclerites of complex 3 ( Fig. 11 A): circumference length 1234 ± 27.5(1215–1254, n = 2); total length 495 ± 31.4(473–517, n = 2); total diameter 362 ± 38.3(335–389, n = 2); width 90 ± 4.4(87–93, n = 2); shaft length 494 ± 33.6(470–518, n = 2); inner diameter 274 ± 36.8(248–300, n = 2); aperture angle 48° ± 7.9(43°–54°, n = 2); aperture 257 ± 71.2(207–307, n = 2); hook-side curve length 97 ± 7.4(92–103, n = 2) and shaft-side curve length 120 ± 25.3(102–138, n = 2). Complex 3 sucker-sclerite hook length 151 ± 13.5(141–161, n = 2); hook curve length 17 ± 3.5(15–20, n = 2); aperture 120 ± 10.7(112–127, n = 2) and base width 46 ± 4.1(43–49, n = 2).

Sucker sclerites of complex 2 ( Fig. 11 B): circumference length 1174 ± 61.3(1130–1217, n = 2); total length 505 ± 19.0(491–518, n = 2); total diameter 359 ± 29.9(338–381, n = 2); width 85 ± 12.1(77–94, n = 2); shaft length 502 ± 18.0(490–515, n = 2); inner diameter 276 ± 19.8(262–290, n = 2); aperture angle 47° ± 6.6(43°–52°, n = 2); aperture 260 ± 51.3(223–296, n = 2); hook-side curve length 99 ± 12.0(90–107, n = 2) and shaft-side curve length 120 ± 21.9(104–135, n = 2). Complex 2 sucker-sclerite hook length 150 ± 12.3(142–159, n = 2); hook curve length 19 ± 3.1(17–21, n = 2); aperture 117 ± 12.7(108–126, n = 2) and base width 44 ± 1.6(43–45, n = 2).

Sucker sclerites of complex 1 ( Fig. 11 C) similar in size to complex 2 and 3 with circumference length 1217 ± 31.6(1195–1239, n = 2); total length 476 ± 27.0(457–495, n = 2); total diameter 365 ± 44.8(333–396, n = 2); width 83 ± 10.8(75–90, n = 2); shaft length 478 ± 27.1(458–497, n = 2); inner diameter 285 ± 35.3(260–310, n = 2); aperture 241 ± 24.6(223–258, n = 2); hook-side curve length 101 ± 15.0(90–111, n = 2) and shaft-side curve length 101 ± 1.3(100–102, n = 2). Complex 1 sucker-sclerite hook length 152 ± 3.7(149–155, n = 2); hook curve length 14 ± 3.5(11–16, n = 2); aperture 124 ± 2.2(122–126, n = 2) and base-width 43, n = 2.

Dorsal haptoral appendix 942, n = 1 long, 368, n = 1 wide. Terminal suckers of appendix 260 ± 8.3(254–266, n = 2) long, 139 ± 0.4(149–150, n = 2) wide. Single pair of hamuli present before terminal suckers.

Hamulus ( Fig. 11 D) total length 65 ± 2.0(64–66, n = 2); hook point length 22 ± 3.8(20–25, n = 2); hook shank length 20, n = 2; total diameter 30 ± 2.5(28–32, n = 2); hook distal point width 3, n = 2; outer aperture angle 20° ± 0.7(20°–21°, n = 2); aperture 79 ± 2.0(78–81, n = 2); hook shank base width 8 ± 2.6(6–10, n = 2); inner root-shaft length 44 ± 8.2(38–50, n = 2); outer root-shaft length 47 ± 7.9(41–53, n = 2); root base angle 96° ± 7.4(91°–101°, n = 2), and root base width 23 ± 2.6(22–25, n = 2). Testes irregular in shape, 54, n = 1 in number; 62 ± 5.9(52–70, n = 10) wide. Vas deferens sinuous, surrounded by small gland cells along the majority of its length. Vas deferens loop proximal to entrance into cirrus, absent. Unarmed muscular cirrus total length 232, n = 1; maximum width 228, n =1.

Ovary (dextral = 1) 678, n = 1 long, anteriorly lobed, coiled posteriorly, ascending to oviduct, branching to sac-like, reduced seminal receptacle. Ootype smooth, leading to uterus, dorsal to ovary, ventral to vas deferens. Ovate eggs connected by tendrils at each pole. Eggs (in uterus) 146 ± 5.6(133–149, n = 10) long, 66 ± 2.7(62–69, n = 10) wide. Parallel vaginal ducts with heavily glandulo-muscular distal portion and thin-walled proximal portion. Ventral vaginal pores muscular, lateral to median portion of cirrus. Follicular vitellarium originates posterior to vaginal pores. Excretory pores not observed.

Remarks. The voucher whole mount examined in this study (SAMCTA 29468) is comparatively shorter in most soft-body structures resulting from post flat-fixation after preservation in absolute alcohol prior to shipment to South Africa from Japan. In addition, the voucher is fixed in such a way that the haptor appears symmetrical. As a result it was not used to provide a whole mount figure to represent the species. All Callorhynchocotyle species possess asymmetrical haptors. Both vouchers agree with the original description in hard body structures. However, it should be noted that both the outer and inner hamulus root structures have been measured differently in the present study, given the obvious differences in the measurements between the present study and the original description of Kitamura et al. (2006). These authors did not indicate how these structures were measured in the original description.

Callorhynchocotyle sagamiensis is the most recent addition to the genus and the second Callorhynchocotyle species reported from a member of the Chimaeridae . Similar to C. hydrolagi , C. sagamiensis also possesses sucker sclerites of similar size throughout all 3 sucker sclerite complexes.

The complex 1 sucker sclerites of C. sagamiensis are longer in total, shaft and hook-side curve lengths and wider in total and inner diameter and sclerite widths than those of C. marplatensis , C. callorhynchi and C. amatoi . The complex 1 sucker-sclerite hook length is longer, and the base width wider than those of C. marplatensis , C. callorhynchi and C. amatoi .

The total length of C. sagamiensis complex 2 sucker sclerites is shorter than the total length of those of C. marplatensis , but the sclerite width is wider than that of both C. marplatensis and C. callorhynchi . The shaft length is longer than that of C. amatoi . The hook length of complex 2 sucker sclerites is longer than that of C. amatoi . The base width is wider than the complex 2 sucker-sclerite base widths of C. marplatensis , C. callorhynchi and C. amatoi .

Complex 3 sucker sclerites of C. sagamiensis are longer in total length and wider in total width and inner sclerite diameter, than those of C. hydrolagi . The shaft length is greater than both that of C. amatoi and C. hydrolagi , and the hook-side curve length is shorter than that of C. callorhynchi and C. marplatensis , but longer than that of C. amatoi and C. hydrolagi . The complex 3 sucker-sclerite hook length is shorter than that of C. callorhynchi and C. marplatensis , but longer and wider than that of C. hydrolagi .

The hamulus total and hamulus-hook shank lengths are longer than that of C. amatoi and C. marplatensis , but less than that of C. hydrolagi . Total width is narrower than that of C. hydrolagi , and the hamulus-hook distal point width is wider than that of C. amatoi . The outer root-shaft length is longer than that of C. hydrolagi .

Callorhynchocotyle sagamiensis can be differentiated from C. marplatensis by the presence of papillae in the oral as well as the haptoral suckers, and from C. callorhynchi and C. amatoi by the similarity in size of all sucker sclerites, where those of the former (and C. marplatensis ) include smaller complex 1 sucker sclerites. Callorhynchocotyle sagamiensis is most similar to C. hydrolagi , but differs in complex 3 sucker sclerite, hamulus, and cirrus morphology. The cirrus in C. sagamiensis is currently unique amongst the Callorhynchocotyle species and serves as a discriminating character as identified by Kitamura et al. (2006). It consists of a single muscular tube not differentiated into the proximal and ovate (bulbous) distal portions of the generic diagnosis of Boeger et al. (1989). Additionally, C. sagamiensis differs from all of the other Callorhynchocotyle species in possessing the widest sucker sclerites of the third sucker sclerite complex.

Figures

FIGURE 11. Callorhynchocotyle sagamiensis sucker sclerites of complexes 1 (A), 2 (B) and 3 (C), and hamulus (D). Scale bars: A, B, C = 360 µm, D = 60 µm.