Kapsulotaenia tidswelli ( Johnston, 1909 ) Freze, 1963

Chambrier, Alain De, Brabec, Jan & Scholz, Tomáš, 2020, Molecular data reveal unexpected species diversity of tapeworms of Australasian reptiles: revision of Kapsulotaenia (Cestoda: Proteocephalidae), Zootaxa 4869 (4), pp. 529-561 : 543

6. Kapsulotaenia tidswelli ( Johnston, 1909) Freze, 1963

( Figs. 4 , 10C )

Syns. Acanthotaenia tidswelli Johnston, 1909 ; Ichthyotaenia tidswelli ( Johnston, 1909) Beddard, 1913 ; Proteocephalus tidswelli ( Johnston, 1909) Johnston, 1911 ; Crepidobothrium tidswelli ( Johnston, 1909) Meggitt, 1927

Type and only known host. Lace monitor, Varanus varius (White, 1790) ( Squamata : Varanidae ).

Site of infection. Intestine.

Type locality. Bathurst , New South Wales, Australia .

Additional localities. Myall Lake, New South Wales, Australia; Tamborine, Queensland, Australia.

Type material. Syntypes—4 slides with 1 scolex, and 6 fragments, 5.5.1908 ( AHC 28409), and 2 slides with 3 scoleces and 25 fragments ( AHC 35220 and 35222) .

DNA sequences. lsr DNA: MT 611156 , MT 611157 (Aus135b, 135a), cox 1: MT 627449 , MT 627456 (Aus135b, 135a).

Material studied. Syntypes; vouchers from V. varius , Australia—63 slides with 2 specimens (2 scoleces), their cross sections and sections of the host intestine, Myall Lake , New South Wales, 8.ii.1928 (MHNG-PLAT-94073; NHMUK 1987.8.10.206–240); 10 slides with several specimens (4 scoleces), Tamborine, Queensland, Australia, collected by A. de Chambrier on 30.x.2003 (Aus135; MHNG-PLAT-36697, 68966; 1 of 9 hosts infected, i.e., prevalence of 11%) .

Morphological description (see Table 2 for measurements). Strobila moderately long (total length of 49–104 mm). Proglottids much longer than wide. Scolex small, wider than neck, with pyriform rostellum containing apical organ. Retractor muscles connecting rostellum with neck region present. Testes ovoid, in one or two layers and in two fields converging medially and anteriorly, interrupted porally by cirrus-sac and vagina. Vas deferens convoluted, in anterior median field. Cirrus-sac pyriform; cirrus armed with small spines (spinitriches). Ovary butterfly-shaped. Vagina opens posterior or anterior to cirrus-sac. Genital pore irregularly alternating, post-equatorial. Vitelline follicles interrupted at level of cirrus-sac on ventral side. Vitelline follicles in two lateral bands, not reaching anterior margin of proglottids but reach almost to their posterior part. Uterine stem not reaching anterior, nor posterior margin, with lateral diverticula almost invisible. Eggs in clusters.

Remarks. The species was described as Acanthotaenia tidswelli from Varanus varius in New South Wales, Australia ( Johnston 1909) and transferred to Kapsulotaenia by Freze (1963). Some differences between measurements of the type specimens and our material (Aus135), such as strobila length, proglottid width and sucker width, may have been caused by different fixation (flattening versus heat-fixation) and the poor state of the original material.

Kapsulotaenia tidswelli differs from K. frezei and K. saccifera by the absence of banana-shaped egg clusters, from K. pythonis by the number of eggs in cluster (19–22 versus 6–9), from K. sandgroundi and K. nybelini n. sp. by a lower relative width of the ovary (63–73% versus 42–59% and 51–58%, respectively), from K. chisholmae by a shorter strobila (length 49–104 mm versus 180–315 mm), by a different egg number in each cluster (6–9 versus 8–13) and by a different position of the vagina to cirrus-sac (44% versus 93% anterior); from K. beveridgei n. sp. and K. cannoni n. sp. by the size of the scolex (415–600 μm versus 335–475 μm and 275–390 μm) and by the size of the embryophore (19–32 μm versus 38–41 μm and 39–40 μm), and from K. varia by the proglottid shape (longer and narrower versus shorter and wider) and by the mean number of testes (86 versus 103) ( Table 2 ).

Tapeworms found in the host Aus005 in Queensland is provisionally designated as Kapsulotaenia sp. 6 based mainly on molecular data ( Fig. 1 ; lsr DNA—MT611158; cox 1— MT627457 ), even though they are similar in their morphology, including the shape of proglottids and the number of testes with those of K. tidswelli ( Fig. 4 ; Table 2 ).

Freze (1965) listed three species of monitors, namely Varanus varius , V. gouldii and V. bellii (syn. of V. varius ), as definitive hosts of this cestode. However, Johnston (1909) reported only V. varius as the definitive host of K. tidswelli in its original description. Based on the present data ( Figs. 1 , 2 ), we consider K. varia to be a specific parasite of lace monitor. Surface ultrastructure (microtriches) of K. tidswelli was studied by Thompson et al. (1980); this was one of the pioneer studies that used transmission electron microscopy to study cestode microtriches (see Chervy 2009).

Figures

FIGURE 1. Phylogenetic relationships of tapeworms of the subfamily Acanthotaeniinae (Cestoda: Proteocephalidae) based on a maximum likelihood analysis of concatenated (lsrDNA +cox1) data. Nodal values depict standard bootstrap supports (1,000 resamples) over 50, dashed lines are used for nodes with bootstrap values below 50. Branch length scale bar indicates number of substitutions per site. GenBank accession numbers can be found in Table 1.

FIGURE 2. Maximum likelihood single-gene phylogenies of Kapsulotaenia based on cox1 (above) and lsrDNA (below) data. Nodal values depict standard bootstrap supports (1,000 resamples) over 50, dashed lines are used for nodes with bootstrap values below 50. Branch length scale bar indicates number of substitutions per site. GenBank accession numbers can be found in Table 1.

FIGURE 4. Kapsulotaenia tidswelli (Johnston, 1909) from Varanus varius, Australia (syntypes AHC 35820—A, AHC 28409— B, D; new material Aus135—C, E, F). A–C—scolex; D, F—mature proglottids, ventrally (D) and dorsally (F); E—mature proglottid—hologenophore, dorsally.

FIGURE 10. Egg capsules of species of Kapsulotaenia (eggs from unmounted proglottids drawn in distilled water). A—K. pythonis from Morelia viridis (syntype); B—Kapsulotaenia sp. 6 from Varanus varius (host AUS005); C—K. tidswelli from Varanus varius (host Aus135); D, F—K. varia from V. varius (hosts Aus016 and Aus137); E—K. beveridgei n. sp. from V. rosenbergi (host Aus028); G, H—K. cannoni n. sp. from V. gouldii (host Aus140).