Anthocephalum mattisi, Ruhnke, Timothy R., Caira, Janine N. & Cox, Allison, 2015

Ruhnke, Timothy R., Caira, Janine N. & Cox, Allison, 2015, The cestode order Rhinebothriidea no longer family-less: A molecular phylogenetic investigation with erection of two new families and description of eight new species of Anthocephalum, Zootaxa 3904 (1), pp. 51-81 : 66

Anthocephalum mattisi n. sp.

( Figs. 1 D, 4 C–D, 5 F–J)

Type host. Dasyatis sp. (sensu Naylor et al. 2012a).

Type locality. eastern Atlantic Ocean off Mbour (14°24'22"N, 16°58'6"W), Senegal; (SE–222).

Site of infection. Spiral intestine.

Type material. Holotype ( MNHN HEL 433); 1 paratype ( MNHN HEL 434); 3 paratypes ( USNM 1251815–1251817), 6 paratypes (LRP 8534–8539), hologenophore (LRP 4219).

Etymology. The species is named for the late Dr. Tom Mattis, in honor of his contributions to understanding the life histories of the cestodes of elasmobranchs.

Description. Based on 14 whole mounts and 2 scoleces prepared for SEM. Worms slightly craspedote, euapolytic 7.3–22.3 mm long, with 34–50 proglottids; maximum width 565–1,000 at scolex. Scolex with 4 bothridia and short cephalic peduncle. Bothridia stalked, circular, with 82–95 marginal loculi and round apical sucker; apical sucker 45–57 in diameter. Proximal surfaces of bothridial rims covered with acicular filitriches; proximal surfaces of marginal loculi covered with small scolopate spinitriches and acicular filitriches ( Figures 5 G, H), proximal non-locular surfaces of bothridia covered with acicular filitriches ( Figure 5 I). Distal bothridial surfaces and distal surfaces of apical suckers covered with small gladiate spinitriches and acicular filitriches ( Figure 5 J).

Immature proglottids initially wider than long, becoming longer than wide with maturity, length:width ratio at mid-strobila 1.7–7.7:1. Terminal and subterminal proglottids 889–2,426 long by 170–285 wide, length:width ratio 3.4–11.7:1, with dorsal and ventral pair of excretory ducts. Testes 36–52 in number, round, 33–59 in diameter, arranged in 2 regular columns anterior to cirrus-sac. Cirrus-sac posteriorly recurved, 137–344 long by 74–170 wide, containing coiled cirrus; cirrus armed with spinitriches. Vas deferens dorsal, coiled anterior to cirrus-sac, expanded and descending to ovarian bridge. Genital pores lateral, 18–36% of proglottid length from posterior end, irregularly alternating. Vagina sinuous, extends from Mehlis’ gland anteriorly, then ventral and lateral to cirrus-sac, opening into genital atrium. Ovary near posterior end of proglottid, follicular, H-shaped in frontal view, symmetrical, 164–505 long by 96–183 wide. Ovicapt at posterior margin of ovarian bridge, ventral, 35–50 in diameter. Uterus median, ventral, extending from ovarian bridge to anterior margin of proglottid. Uterine duct inconspicuous. Vitellarium follicular; follicles 6–25 long by 17–55 wide, in 2 lateral bands; each band consisting of 2–3 dorsal and 2–3 ventral irregular columns of follicles, extending from near anterior to near posterior end of proglottid, interrupted by ovary and cirrus-sac, post-poral follicles present. Excretory ducts lateral, consisting of 1 dorsal and 1 ventral pair.

Remarks. Of the 12 species of Anthocephalum described to date, A. mattisi n. sp. differs from all except Anthocephalum alicae , A. decrisantisorum , A. jensenae , A. kingae and A. michaeli in having testes arranged in two regular columns, rather than in more than two irregular columns. It lacks the muscular genital pore seen in A. decrisantisorum . This new species exhibits a greater number of marginal loculi than both A. alicae and A. jensenae (82–95 vs. 57–80 and 61–78, respectively). It differs from A. kingae in possessing many more vitelline follicles in each lateral band and smaller apical suckers on its bothridia (45–57 vs. 60–75). It most closely resembles A. michaeli from Dasyatis longa in the Gulf of California, but differs in testis shape (round vs. oblong). In addition, while not deviating substantially in range, the new species also differs from A. michaeli in possessing significantly (P<0.001) more proglottids per worm (mean of 44 vs. mean of 31) and testes per proglottid (mean of 45 vs. mean of 39).

Figures

FIGURE 1. Line drawings of Anthocephalum n. spp. A. Anthocephalum decrisantisorum n. sp., paratype (LRP 8523). B. Anthocephalum healyae n. sp., holotype (QM G 234600), not all anterior proglottids shown. C. Anthocephalum jensenae n. sp., holotype (QM G 234603). D. Anthocephalum mattisi n. sp., holotype (MNHN HEL 433). E. Anthocephalum meadowsi n. sp., holotype (QM G 234607). F. Anthocephalum odonnellae n. sp., holotype (MZUM [P] 2014.5 [H]). G. Anthocephalum papefayei n. sp., paratype (LRP 8549). H. Anthocephalum philruschi n. sp., (LRP 8555). For comparative purposes, all drawings are at same scale.

FIGURE 5. Scanning electron micrographs of Anthocephalum jensenae n. sp. and Anthocephalum mattisi n. sp. A. A. jensenae n. sp., scolex. Letters indicate locations of Figures 5 D – E. B. A. jensenae n. sp., marginal loculi. Letter indicates location of Figure 5 C. C. A. jensenae n. sp., proximal surface of marginal loculus near bothridial rim. D. A. jensenae n. sp., proximal surface of bothridium. E. A. jensenae n. sp., distal surface of bothridium. F. A. mattisi n. sp., scolex. Letters indicate locations of Figures 5 H – J. G. A. mattisi n. sp., marginal loculi. Letter indicates location of Figure 5 H. H. A. mattisi n. sp., proximal surface of marginal loculus near bothridial rim. I. A. mattisi n. sp., proximal surface of bothridium. J. A. mattisi n. sp., distal surface of bothridium.