Tetracampos martinae Kuchta

Kuchta, Roman, Burianová, Alena, Jirkú, Miloslav, Chambrier, Alain, Oros, Mikuláš, Brabec, Jan & Scholz, Tomáš, 2012, Bothriocephalidean tapeworms (Cestoda) of freshwater fish in Africa, including erection of Kirstenella n. gen. and description of Tetracampos martinae n. sp., Zootaxa 3309, pp. 1-35 : 22

Tetracampos martinae Kuchta n. sp.

( Figs 53–60 )

Type host: Bagrus meridionalis (Linnaeus) ( Siluriformes : Bagridae ).

Type locality: Deep waters of the southeast arm of Lake Malawi, Malawi (14°06ʹS, 35°03ʹE).

Distribution: Zambezi basin – Lake Malawi.

Type material: Holotype and paratype ( IPCAS C-608 ) (field No. SSH96-09-K-1).

Material studied: Two type specimens ( IPCAS C-608).

Etymology: The new species is named in honour of Martina Borovková, Institute of Parasitology, Academy of Sciences of the Czech Republic, for her extraordinary technical support.

Description (based on 2 specimens, 1 without scolex): Bothriocephalidea , Bothriocephalidae . Strobila up to 19 cm long, oval in cross section; maximum width 1 mm. External and internal segmentation present; segments wider than long, slightly craspedote ( Fig. 53 ).

Two pairs of longitudinal osmoregulatory canals; dorsal canals narrow (diameter up to 10); ventral canals wide (diameter up to 25), connected by transverse anastomoses. Inner longitudinal musculature well developed, muscle fibres diffused ( Fig. 60 ).

Scolex elongate, with maximum width near posterior margin of scolex ( Fig. 54 ), 620 long by 160 wide. Apical disc weakly developed, 100 wide and 28 high, armed with 39 small hooks 44–100 (75 ± 5; n = 15) long, arranged in two lateral semicircles separated from each other on dorsal and ventral side ( Fig 56 ). Hooks variable in size in each semicircle, with largest hook in each corner of apical disc ( Figs 55, 56 ). Bothria elongate, shallow, 409 long by 80 wide. Neck present ( Fig. 53 ).

Immature segments 78–135 long by 191–560 wide (n = 10) ( Fig. 53 ). Mature segments wider than long, 103– 211 long by 690–724 wide; segment length/width ratio 0.15–0.29: 1 (n = 10). Gravid segments wider than long, 220–380 long by 1015–1059 wide; segment length/width ratio 0.21–0.37: 1 (n = 10) ( Figs 53, 57, 59 ).

Testes medullary, oval, 15–19 (n = 10) in number per segment, 36–72 (51 ± 10; 10) in diameter, forming 2 narrow longitudinal bands (7–10 testes per band), confluent between segments, absent medially and near lateral margins ( Fig. 57 ). Cirrus-sac small, thin-walled (thickness of sac wall up to 6), pyriform, 46–59 long by 59–75 wide (length/width ratio 0.61–0.93: 1) (n = 10), pre-equatorial (at 13–44% of length of mature segment from anterior margin; n = 10) ( Figs. 57, 60 ). Internal seminal vesicle absent; cirrus unarmed ( Fig. 60 ). Vas deferens forms numerous loops posterolateral to cirrus-sac; internal sperm ducts strongly coiled. Genital pore dorsal, median, near anterior margin of segment, transversely elongate ( Fig. 60 ).

Ovary symmetrical, circular biscuit-shaped, lobulate, 84–107 long by 199–242 wide (n = 10) ( Fig. 57 ). Vagina a straight, thin-walled tube, 5–11 in diameter, opens posterior to cirrus-sac into genital atrium; vaginal sphincter absent. Vitelline follicles numerous, small, spherical, 24–40 in diameter (n = 25), medullary, form 2 wide longitudinal bands confluent between segments, separated medially, rarely connected by several follicles in postovarian region ( Fig. 57 ).

Uterine duct winding, short, filled with eggs. Uterus thin-walled, median, spherical, enlarged in gravid segments, up to 277 long and 450 wide ( Fig. 59 ). Uterine pore thick-walled, opens in centre of uterus. Eggs oval to spherical, 40–64 long by 41–53 wide (n = 10), with external hyaline membrane and internal granular layer surrounding fully formed oncospheres 28–45 long by 30–36 wide (n = 10) in terminal segments; eggs enlarging during their development in uterus ( Figs 53, 58 ).

Remarks: Tapeworms from Bagrus meridionalis from Lake Malawi are placed in Tetracampos based on the medullary position of vitelline follicles and morphology of eggs, which are unique characters of the genus, missing in all other bothriocephalideans possessing the scolex armed with hooks on the apical disc, i.e. species of Kirstenella , Oncodiscus Yamaguti, 1934 , Polyonchobothrium and Senga (see Kuchta et al. 2008b). The new species differs from congeneric T. ciliotheca in the following characteristics: (i) much longer and dorsoventrally flattened strobila (19 cm vs. oval, much smaller strobila less than 3 cm); (ii) larger hooks (up to 100 µm long vs. shorter than 52 µm); and (iii) mature and gravid segments much wider than long vs. almost quadrate in T. ciliotheca . The definitive host of T. martinae is Bagrus meridionalis , which is endemic to Lake Malawi, whereas T. ciliotheca is specific to Clarias spp. Tetracampos martinae is the second species of Tetracampos , the diagnosis of which is emended below to reflect morphological differences between both species of the genus.

Figures

FIGURES 53 – 60. Line drawings of Tetracampos martinae Kuchta, n. sp. ex Bagrus meridionalis from Lake Malawi (IPCAS C- 608). 53, Total view of the worm with anterior and posterior part of the body. 54, Scolex, lateral view. 55, Detail of hooks. 56, Complete circle of hooks. 57, Gravid segment, ventral view, eggs not illustrated. 58, Egg. 59, Gravid segment, eggs not illustrated. 60, Cross-section of the gravid segment in the level of cirrus-sac.