Australophiotaenia longmani ( Johnston, 1916 ) Chambrier & Beveridge & Scholz, 2018

Chambrier, Alain De, Beveridge, Ian & Scholz, Tomáš, 2018, Tapeworms (Cestoda: Proteocephalidae) of Australian reptiles: hidden diversity of strictly host-specific parasites, Zootaxa 4461 (4), pp. 477-498 : 482-483

Australophiotaenia longmani ( Johnston, 1916) n. comb.

( Figs. 5–10 )

Syns Crepidobothrium longmani ( Johnston, 1916) Meggitt, 1927 ; Proteocephalus longmani ( Johnston, 1916) Hughes, Barker & Dawson, 1941 ; Ophiotaenia longmani ( Johnston, 1911) Wardle & McLeod, 1952

Type and only host. Ramsay’s python, Aspidites ramsayi (Macleay, 1882) ( Ophidia : Pythonidae ).

Site of infection. Intestine.

Type locality. Yeulba (now usually spelled as Yuleba), Queensland, Australia (26°37′0″S 149°23′0″E).

Distribution. Queensland, Australia.

References. Johnston (1916), de Chambrier & de Chambrier (2010); Scholz et al. (2013).

Material studied. 6 syntypes (AHC 20085, 20523, 20733, 28408, QM G16/468, QM 463—16 whole-mounts and 3 cross sections); 4 whole mounts and 9 cross sections of 2 specimens from Aspidites ramsayi in Yuleba , Queensland, Australia (MHNG-PLAT-36551; host field number AUS 013).

Redescription. Based on type-material and recently collected material. Cestodes large, more than 200 mm in length; maximum width 2.2 mm. Strobila acraspedote, anapolytic. Immature proglottids wider than long to quadrate (length: width ratio 0.74–1.02), mature, pregravid and gravid proglottids longer than wide (length: width ratio 1.49–3.58).

Internal longitudinal musculature composed by small bundles of muscle fibres. Ventral osmoregulatory canals situated between vitelline follicles and testes. Dorsal osmoregulatory canals almost invisible in mature and gravid proglottids.

Scolex 405–505 (x = 455, n = 6) long and 710–990 (x = 870 n = 6) wide, slightly wider than neck, 530–780 wide. Suckers uniloculate, spherical, slightly embedded, 270–395 (x = 345, n = 24) in diameter, representing 42– 45% of scolex width. Apical organ absent, but diffuse concentration of chromophilic cells present in scolex apex.

Testes medullary, in one layer, forming two lateral bands (poral band separated by terminal genitalia into preporal and postporal groups). Testes 209–275 (x = 242, n = 5) in number, with 108–133 (x = 124, n = 5) aporal testes, 57–76 (x = 67, n = 5) preporal testes and 35–66 (x = 51, n = 5) postporal testes. Testes oval to elongate, 40– 65 long to 35–50 wide, present also in gravid proglottids.

Cirrus-sac oval to pyriform, thick-walled, 340–420 long and 260–290 wide; length: width ratio 0.65–0.80; length of cirrus-sac represents 30–39% (x = 34%, n = 7) of proglottid width. Cirrus robust, its length representing up to 70% of cirrus-sac length. Sperm duct strongly coiled. Vas deferens strongly coiled, situated between proximal part of cirrus-sac and midline of proglottids, but never crossing it. Genital atrium shallow; genital pores alternating irregularly, equatorial or slightly postequatorial, at 49–55% of proglottid length from anterior margin.

Ovary medullary, bilobed, 515–720 wide; width of ovary represents 58–67% (x = 53%, n = 7) of proglottid width; relative size of ovary (see de Chambrier et al. 2012) 2.3%. Mehlis’gland 75–95 in diameter, representing 8.3–9.3% of proglottid width. Vaginal canal slightly coiled in proximal part, enlarged to form small seminal receptacle dorsal to ovarian isthmus. Terminal (distal) part of vaginal canal (pars copulatrix vaginae) surrounded by circular vaginal sphincter and chromophilic cells ( Fig. 7 ). Vagina anterior (67%) or posterior (33%, n = 12) to cirrus-sac.

Vitelline follicles paramuscular (i.e. some follicles penetrating to the medulla between fibres of inner longitudinal musculature; see de Chambrier 1990 for definition) arranged in 2 lateral fields near margins of proglottids on the dorsal side ( Fig. 8 ), occupying porally 88–97% of proglottid length and aporally 89–94% of proglottid length, interrupted at level of cirrus-sac and vagina ( Figs. 6, 7 ).

Primordium of uterine stem medullary, present in immature proglottids. Development of uterus of type 1 according to de Chambrier et al. (2004, 2015). In pregravid proglottids, uterus occupying up to 17% of proglottids width, with 32–43 thin-walled lateral diverticula on each side. In gravid proglottids, diverticula occupying up to 75% of proglottid width. Uterine duct entering uterus almost at level of ovarian isthmus.

Eggs in clusters of 3– 6 eggs (3 eggs = 4% of clusters; 4–26%, 5–64%, 6–6%, respectively; n = 78). Outer envelope hyaline, up to 270 in diameter; embryophore three-layered, 32–36, 29–33, 19– 20 in diameter, respectively; oncosphere 12–13 in diameter, with six embryonic hooks 6–8 long.

Remarks. Johnston (1916) described this species from somewhat decomposed individuals taken by H. A. Longman from a preserved specimen of Aspidites ramsayi , a python captured at Yeulba (another spelling Yeluba) in western Queensland ( Johnston, 1916). Numerous conspecific tapeworms were obtained by one of the present authors (A. C.) in 2001 from the type host captured at the type locality, but the examined python was frozen before examination. Nevertheless, the new material made it possible to redescribe the species, which seems to be a specific parasite of Ramsay’s python endemic to Australia (occurring from Western Australia through southern Northern Territory and northern South Australia to southern Queensland and northwestern New South Wales) ( Cogger, 2014).

Syntypes of A. longmani are smaller than newly collected specimens (total length of 94 mm versus more than 200 mm in length; maximum width only 1 mm in syntypes compared to 2.2 mm in the new material—Johnston, 1916 and present study). This species differs from other species of Australophiotaenia described from reptiles in Australia by the presence of 3 to 6 eggs in cluster, and a more powerful longitudinal internal musculature. It differs from A. mjobergi by a different PC ratio (30–39% versus 25–28%), and by a different OV% ratio (2.3% versus 4.7%). The cirrus-sac of the species is large and contains a strongly coiled internal sperm duct; the vaginal canal is equipped with a large sphincter.

Scholz et al. (2013) provided sequences of two mitochondrial genes, rrn L and cox 1 ( KC786004 and KC785991 , respectively), of A. longmani from A. ramsayi in Yuleba , Surat Road, Queensland, Australia (host field number AUS 13; paragenophore as MHNG-PLAT-36551).

Figures

FIGURES 5–10. Australophiotaenia longmani (Johnston, 1916) n. comb., 5, 6. Syntype from Yuleba, Queensland, Australia [Coll. No. QMNH G16/468] 5. Scolex. 6. Mature proglottid, dorsal. 7–10. Voucher MHNG-PLAT-36551 (field No. AUS 013). 7. Pregravid proglottid, dorsal. 8. Cross section at level of uterus with eggs in capsules. 9, 10. Eggs in capsules.