Ahamulina catarina, Marques, Fernando P. L., Jensen, Kirsten & Caira, Janine N., 2012

Marques, Fernando P. L., Jensen, Kirsten & Caira, Janine N., 2012, Ahamulina n. gen. (Cestoda: Diphyllidea) from the polkadot catshark, Scyliorhinus besnardi (Carcharhiniformes: Scyliorhinidae), off Brazil, Zootaxa 3352, pp. 51-59 : 53-55

Ahamulina catarina n. gen., n. sp.

( Figs. 1–18 )

Type host: Scyliorhinus besnardi Springer and Sadowsky, 1970 ( Scyliorhinidae III sensu Naylor et al. [2012]: Carcharhiniformes ), polkadot catshark.

Type locality: Off Itajaí (26°54'55.08"S, 48°39'9.00"W), Santa Catarina , Brazil, Atlantic Ocean.

Site of infection: Spiral intestine.

Type material: Holotype ( MZUSP 6487a; whole mount); 6 paratypes ( MZUSP 6487b–g; 4 whole mounts, 1 scolex longitudinal section series and its whole-mounted voucher, and 1 proglottid cross-section series), 5 paratypes ( USNPC 105708–105712; 4 whole mounts and 1 proglottid cross-section series), 4 paratypes (LRP 7886– 7889; 4 whole mounts); scolex prepared for SEM and its strobilar voucher retained in the senior author’s personal collection at USP.

Etymology: The specific epithet, catarina , used as a noun in apposition, is in reference to the colloquial Brazilian term (" catarina ") for the inhabitants of Santa Catarina , the state bordering the waters from which the host for this species was collected.

Description (based on 9 complete and 6 incomplete whole-mounted specimens, cross-sections of 2 proglottids, longitudinal sections of 1 scolex, and 1 scolex prepared for SEM): Worms apolytic, 23–45 (30±7; 8) mm long; greatest width at level of scolex; proglottids acraspedote, 44–65 (59±7; 8) in number. Scolex consisting of scolex proper and cephalic peduncle. Scolex proper 495–644 (596±51; 8) long by 429–544 (479±41; 8) wide, consisting of armed apical organ and 1 dorsal and 1 ventral bothrium. Bothria 455–628 (559±54; 8) long by 428±544 (479±41; 8) wide. Apical organ muscular, small, 136–179 (168±13; 9) long by 95–125 (111±10; 9) wide, with 1 dorsal and 1 ventral group of apical hooks; apical hooks in each group up to 6 in number, solid, not articulated with one another, arranged in single, irregular row, without distinct base, rounded at tips; lateral-most apical hooks on each side slightly smaller than medial 4 hooks; lateral hooks 28–42 (35±6; 7) long by 6–8 (7±1; 7) wide; medial hooks 34–46 (40±4; 18) long by 7–11 (9±1; 18) wide; hook formula {6/6}. Cephalic peduncle unarmed, craspedote, not extending posterior to bothria, 412–599 (500±54; 9) long by 247–353 (287±37; 9) wide.

Distal and proximal bothrial surfaces covered with capilliform filitriches and trifurcate spinitriches ( Figs. 9 and 10 , respectively). Surfaces of apical organ, cephalic peduncle, and strobila covered with capilliform filitriches only ( Figs. 8, 11 , and 12, respectively).

Immature proglottids 42–47 (45±2; 6) in number, initially wider than long, becoming longer than wide with maturity ( Fig. 1 ); posterior-most immature proglottid 584–894 (693±119.1; 5) long by 323–403 (362.4±34.4; 5) wide. Mature proglottids 10–17 (12±3; 6) in number, 728–1,892 (1,153±228; 47) long by 291–586 (460±70; 47) wide, length:width ratio 1.7–3.7:1. Gravid proglottids 1–8 (5±2; 7) in number, subterminal gravid proglottid 864– 1,900 (1,386±252; 38) long by 460–373 (590±82; 38) wide, length:width ratio 1.6–3.6:1, terminal gravid proglottid 1,574–2,071 (1,895±180; 7) long by 418–722 (588±117; 7) wide, length:width ratio 2.4–4.5:1. Genital pore midventral, 20–31 (26±3; 27)% from posterior margin of mature proglottid; 22–31 (25±3; 20)% from posterior margin of subterminal gravid proglottid, 23–36 (26±6; 4)% from posterior margin of terminal gravid proglottid. Testes 39– 49 (42±4; 6) in number, 59–126 (89±16; 60) long by 36–84 (62±9; 60) wide, arranged in 2 to 3 irregular columns, extending from anterior margin of proglottid to near cirrus sac, 2 to 3 layers deep in cross-section. Cirrus sac containing coiled cirrus, bipartite ( Fig. 5 ), consisting of proximal spherical portion and distal tubular portion, 155–285 (238±49; 10) long; proximal spherical portion 101–151 (121±17; 10) long by 84–133 (111±17; 10) wide; distal tubular portion 79–174 (127±37; 10) long by 32–52 (39±6; 10) wide. Cirrus armed with spinitriches ( Chervy 2009). Internal seminal vesicle absent. External seminal vesicle absent. Vas deferens sinuous, extending from posterior of testicular field to cirrus sac. Ovary near posterior of proglottid, inverted A-shaped in frontal view ( Figs. 4, 5 ), bilobed in cross section ( Fig. 16 ), 134–336 (204±59; 14) long by 182–303 (247±36; 11) wide. Mehlis’ gland dorsal and posterior to ovarian isthmus. Vagina short, sigmoidal, opening posterior to cirrus sac into common genital pore, with numerous glandular cell and with muscular sphincter. Vitellarium follicular; vitelline follicles circumcortical, 24–66 (43±9; 92) long by 17–40 (27±5; 92) wide, extending from anterior margin of proglottid to anterior margin of ovary. Uterus saccate, ventral to vagina, dorsal to cirrus sac, extending from ovarian bridge to mid-level of mature proglottids, extending to near anterior margin of proglottid when fully gravid; uterine duct extensive, strongly sinuous, entering uterus in posterior third. Eggs ovoid ( Fig. 17 ), 39–46 (42±2; 19) long by 17– 26 (23±2; 19) wide, with small, eccentric, terminal knob, unembryonated.

Figures

FIGURES 1 – 5. Line drawings of Ahamulina catarina n. gen., n. sp. from Scyliorhinus besnardi. 1. Holotype (MZUSP 6487 a). 2. Scolex of holotype (MZUSP 6487 a). 3. Detail of apical hooks of holotype (MZUSP 6487 a). 4. Gravid proglottid of paratype, eggs not shown (USNPC 105708); small numbers at arrows indicate location at which sections in Figs. 14 – 17 were taken. 5. Detail of terminal genitalia of gravid proglottid of the paratype (USNPC 105708). Abbreviations: CS, cirrus sac; GP, genital pore; OC, ovicapt; OV, ovary; VA, vagina; VD, vas deferens.

FIGURES 6 – 12. Scanning electron micrographs of Ahamulina catarina n. gen. n. sp. from Scyliorhinus besnardi. 6. Scolex; small numbers indicate location of microthrix images in Figs. 9 – 12. 7. Detail of apical organ; small number indicates location of detail in Fig. 8. 8. Enlarged view of surface of apical organ. 9. Enlarged view of trifurcate spinitriches on distal bothrial surface. 10. Enlarged view of trifurcate spinitriches on proximal bothrial surface (see arrow). 11. Enlarged view of cephalic peduncle. 12. Enlarged view of anterior of strobila.

FIGURES 13 – 18. Ahamulina catarina n. gen. n. sp. from Scyliorhinus besnardi. Figs 13 – 17. Histological sections. 13. Sagittal section through scolex showing bothria free posteriorly for most of their length. 14. Cross section through proglottid at level of testes. 15. Cross section through proglottid at level of genital pore. 16. Cross section through proglottid at level of ovarian bridge. 17. Cross section through proglottid posterior to ovarian bridge. 18. Whole mount of egg; arrow indicates subterminal knob. Abbreviations: AO, apical organ; BO, bothrium; DEV, dorsal excretory vessel; GP, genital pore; MG, Mehlis’ gland; O, ovary; OC, ovicapt; T, testis; UD, uterine duct; UT, uterus; V, vitelline follicle; VA, vagina; VEV, ventral excretory vessel; VR, vitelline reservoir.