Progamotaenia adspersa, Beveridge, I. & Shamsi, S., 2009

Beveridge, I. & Shamsi, S., 2009, Revision of the Progamotaenia festiva species complex (Cestoda: Anoplocephalidae) from Australasian marsupials, with the resurrection of P. fellicola (Nybelin, 1917) comb. nov., Zootaxa 1990, pp. 1-29 : 14-15

Progamotaenia adspersa sp. nov.

( Figs 24–30)

Synonyms: P. festiva ( Rudolphi, 1819) sensu Spratt et al. (1991) .

Host: Macropus irma (Jourdan) (Marsupialia: Macropodidae ).

Site in host: bile ducts.

Types: Holotype Jandakot , Western Australia (32° 07’S 115° 50’E), coll. L. Jue Sue, 13.v.1982, SAM 29358; paratypes, same data, SAM 22308 (S), 11889 (W).

Etymology: from adspersus, meaning scattered.

Material examined: From Macropus irma (black gloved wallaby): Western Australia: types; fragments of several specimens, Collie ( SAM 28948, 29359 , AM 495419 ); 1 specimen and fragments of others, Mt Trio ( SAM 28947 (S), BMNH 2008 . 6.3.8 (S), AM 495420 ) .

Description: Short, slender worms, 46–72 (59, n=4) long, maximum width 3–4 (3.6, n=4) with 165–214 (188, n=4) segments in gravid specimens. Scolex 0.618 –0.975 (0.760) in diameter, squat, mildly 4-lobed; suckers circular, 0.179 –0.260 (0.230) in diameter. Neck short. First mature segment 62–94th (76). Mature segments craspedote, 1.22–2.31 (1.75) wide, 0.21–0.31 (0.25) long. Genital atrium small, slightly posterior to middle of lateral segment margin; cirrus sac small, elongate, extending just beyond osmoregulatory canals, 0.078 –0.195 (0.110) long, 0.039 –0.059 (0.050) wide; cirrus unarmed; internal seminal vesicle occupies approx. 2/3–3/4 of volume of cirrus sac, 0.085 –0.163 (0.120) long, 0.026 –0.039 (0.030) wide; elongate external seminal vesicle, variable in shape, covered with glandular cells, 0.065 –0.150 (0.100) long, 0.033 –0.078 (0.060) wide, extending medially from cirrus sac, sometimes overlying cirrus sac; vas deferens coils medially, dorsal to uterus; testes arranged in anterior half of segment between osmoregulatory canals; no space between canals and testis fields; testes arranged in 2–3 dorso-ventral layers, in single band or 2 slightly separate groups; segments with single band or 2 groups occur in same specimen. Testes 0.033 –0.065 (0.050) in diameter; testis number 63–96 (80). Vagina tubiform, lacking glandular investment, opens to genital atrium posterior to cirrus sac, leads to large ovoid to sub-spherical seminal receptacle 0.117 –0.241 (0.170) x 0.078 –0.143 (0.110). Ovary flabelliform, medial to seminal receptacle 0.065 –0.124 (0.090) x 0.046 –0.117 (0.070), fully developed in few segments only; vitellarium reniform, posterior to ovary, 0.052 –0.163 (0.120) x 0.052 –0.130 (0.090); Mehlis’ gland anterior and medial to vitellarium. Uteri paired in each segment, transverse, tubular; early uterus extends from level of ovary to or beyond proximal pole of cirrus sac; developing uterus extends medially and laterally, lateral extensions crossing osmoregulatory canals dorsally; uteri of each segment do not meet in mid-line. Gravid segments 0.244 –0.406 (0.310) long, 1.54–2.76 (2.26) wide. Egg spherical, shell smooth, 0.058 –0.070 (0.064) in diameter; pyriform apparatus conical, terminating in numerous fine filaments at apex; oncosphere 0.015 –0.018 (0.016) in diameter. Osmoregulatory canals paired; ventral canal generally wider than dorsal, medial to or overlapping dorsal canal; ventral canal 0.020 –0.065 (0.030) in diameter, dorsal canal 0.007 –0.020 (0.012) in diameter; transverse canal connects ventral canal at posterior margin of each segment; tiny accessory canals present overlying ventral canal.

Remarks. This species differs from P. festiva in its small size, from P. aemulans sp. nov., P. dilatata sp. nov., P. fellicola , P. onychogale sp. nov. and P. vombati sp. nov. in having a relatively short cirrus sac which does not extend significantly into the medulla and from P. fellicola and P. aemulans in lacking a distinct space between the testis fields and the osmoregulatory canals. The scolex is smaller than that of P. onychogale and it differs from both P. fellicola and P. onychogale in possessing a short neck. It is similar to P. festiva in being a slender cestode, but differs in the short neck and in not having the suckers on “stalks” as well as in having testes almost meeting in the midline in most segments. It differs from P. corniculata sp. nov. in having a very short neck and from P. pulchella sp. nov. in having groups of testes which may meet in the midline.

This species occurs only in M. irma , a species restricted to the southwest of Western Australia. In this region, the host is in broad sympatry with M. fuliginosus , M. eugenii and Setonix brachyurus . No bile duct cestodes are known from M. eugenii while M. fuliginosus is parasitised by P.effigia and P.pulchella occurs in S. brachyurus .