Semiorbiseptum mariae, Franzese & Ivanov, 2020
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publication ID |
https://doi.org/ 10.11646/zootaxa.4803.2.7 |
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publication LSID |
lsid:zoobank.org:pub:32379908-BED1-40A3-B77D-D43A8BD5FA33 |
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DOI |
https://doi.org/10.5281/zenodo.10564594 |
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persistent identifier |
https://treatment.plazi.org/id/DC40DB73-B24B-4796-B3A5-0FECEE6C27FB |
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taxon LSID |
lsid:zoobank.org:act:DC40DB73-B24B-4796-B3A5-0FECEE6C27FB |
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treatment provided by |
Plazi |
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scientific name |
Semiorbiseptum mariae |
| status |
sp. nov. |
Semiorbiseptum mariae sp. nov.
( Figs. 2–5 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )
Type host. Psammobatis rudis Günther , smallthorn sand skate ( Rajiformes : Arhynchobatidae ).
Additional host. Psammobatis normani McEachran , shortfin sand skate ( Rajiformes : Arhynchobatidae ).
Type locality. Coastal waters off Isla de los Estados, Tierra del Fuego Province (54°30’S, 65°13’W) GoogleMaps .
Additional locality. Coastal waters off Rio Grande , Tierra del Fuego Province (53°34’ S, 66°32’W) and off Miramar, Buenos Aires Province (39°34’S, 56°16’W) GoogleMaps .
Site of infection. Spiral intestine.
Type material. Type material. Holotype MACN-Pa 701 (entire worm), 21 paratypes MACN-Pa 702/1–4, 703, 704/1–13, 705 (12 entire worms, 6 detached gravid proglottids, histological sections of 1 mature proglottid, histological sections of 2 scoleces); 8 paratypes IPCAS C-836 /1 (6 entire worms and 2 detached gravid proglottids).
Prevalence of infection. 78% (7 hosts infected out of 9 examined) in P. rudis and 20% (2 hosts infected out of 10 examined) in P. normani .
Etymology. This species is named after María Rosa Labonia, the first author’s mother.
Description. Based on 31 specimens prepared as follows: whole mounts of 19 entire worms and 8 detached gravid proglottids, serial sections of 1 mature proglottid and 2 scoleces, 9 worms examined with SEM. Worms euapolytic, 4.17–11.17 mm (8.39 mm ± 1.65 mm, 14) long, 420–1,020 (763 ± 204, 12) wide, maximum width at level of scolex. Proglottids craspedote, 71–104 (91 ± 9, 13) per worm, 70–103 (89 ± 8, 13) immature proglottids, 1–3 (1 ± 1, 13) mature proglottids ( Fig. 2A View FIGURE 2 ). Scolex 530–1,910 (868 ± 369, 15) long, composed of 4 stalked bothridia and cephalic peduncle; myzorhynchus absent in adult stage ( Figs. 2A,B View FIGURE 2 , 3A View FIGURE 3 ). Bothridia facially loculate, 395–550 (463 ± 61, 5) long, 168–355 (254 ± 50, 15) wide. Total number of loculi 19–23 (21 ± 1, 15) ( Fig. 2C View FIGURE 2 ). Anterior region of bothridia divided by transverse septa in 7–10 (8 ± 1, 25) loculi arranged in a single column, central region divided in 2–3 (2 ± 0.4, 19) loculi delimited by 2–3 semicircular septa with convex surface facing anteriorly, and posterior region divided by transverse septa in 3–6 (4 ± 1, 15) loculi arranged in a single column, followed by 1–3 pairs of loculi delimited by transverse and medial longitudinal septa, arranged in 2 columns, ending in single posteriormost loculus. In some specimens, semicircular septa extend posteriorly, reaching first loculus of posterior part of bothridium. Anteriormost loculus 35–73 (47 ± 10, 15) long, 45–123 (79 ± 21, 15) wide, muscular wall 5–8 (7 ± 1, 6) thick. Posteriormost loculus 20–43 (35 ± 8, 6) long, 28–60 (49 ± 12, 6) wide, muscular wall 5–8 (6 ± 1, 6) thick. Transverse, semicircular and longitudinal septa formed distally by transverse muscle bundles with underlying layer of radial muscle, proximal portion formed by radial muscles with proximal fibres ending adjacent to each other, forming triangular gap ( Fig. 4 View FIGURE 4 ). Bothridial stalks 110–250 (182 ± 49, 11) long, 68–125 (100 ± 18, 11) wide, attached to centre of bothridium. Cephalic peduncle 163–915 (418 ± 218, 12) long, 73–145 (116 ± 22, 12) wide at posterior end. Apex of scolex covered with capilliform filitriches ( Fig. 3E View FIGURE 3 ). Proximal bothridial surface with gladiate spinitriches interspersed with capilliform filitriches ( Fig. 3D View FIGURE 3 ) and acicular filitriches on the edge ( Fig. 3C View FIGURE 3 ). Distal bothridial surface covered by coniform spinitriches interspersed with acicular filitriches ( Fig. 3B View FIGURE 3 ). Bothridial stalks and cephalic peduncle with capilliform filitriches ( Fig. 3F,G View FIGURE 3 ).
Immature proglottids initially wider than long, becoming longer than wide with maturity. Mature proglottids (excluding terminal proglottid) longer than wide, 420–570 (494 ± 55, 5) long (velum not included in proglottid length), 250–325 (276 ± 35, 5) wide, velum 35–65 (51 ± 11, 5) long, covering 5–7% (6 ± 1, 5) of adjacent proglottid. Terminal mature proglottid 550–950 (761 ± 113, 18) long, 183–295 (244 ± 31, 18) wide, length to width ratio 1: 2–4 (3 ± 0.3, 18) ( Fig. 2D View FIGURE 2 ). Mature proglottids covered by capilliform filitriches ( Fig. 3H View FIGURE 3 ). Testes oval, 20–32 (24 ± 3, 12) per proglottid, 20–50 (33 ± 7, 12, 60) long, 38–65 (52 ± 6, 12, 60) wide, arranged in 2 columns, anterior to cirrus sac ( Fig. 2D View FIGURE 2 ), 1 layer deep in cross-section ( Fig. 5A View FIGURE 5 ). Cirrus sac oval to pyriform, 86–145 (109 ± 20, 8) long, 48–75 (61 ± 9, 8) wide, containing coiled cirrus covered with spinitriches; vas deferens dorsal, highly coiled, entering dorsally at proximal half of cirrus sac ( Figs. 2D,F View FIGURE 2 , 5C View FIGURE 5 ). Genital pores marginal, 36–47% (40 ± 3, 14) of proglottid length from posterior end. Vagina thick-walled, surrounded by darkly stained cells distally, extending from oötype along midline of proglottid to anterior margin of cirrus sac, then laterally along anterior margin of cirrus sac to common genital atrium; vaginal sphincter absent ( Figs. 2D,F View FIGURE 2 , 5B View FIGURE 5 ). Ovary near posterior end of proglottid, H-shaped in dorsoventral view ( Fig. 2D,E View FIGURE 2 ), symmetric, tetralobed in cross-section ( Fig. 5D View FIGURE 5 ), 85–260 (160 ± 41, 11, 22) long, 75–125 (100 ± 17, 8) wide at ovarian isthmus. Mehlis’ gland posterior to ovarian isthmus, 30–43 (36 ± 6, 4) in diameter ( Fig. 2E View FIGURE 2 ). Vitelline follicles 10–23 (13 ± 3, 10, 50) long, 14–35 (21 ± 5, 10, 50) wide, in 1 dorsal and 1 ventral column on each lateral margin of proglottid, extending along entire proglottid, interrupted by vagina and cirrus sac ventrally ( Figs. 2D,F View FIGURE 2 , 5B View FIGURE 5 ). Uterus sacciform, occupying midline of proglottid, from level of ovarian isthmus to near anterior margin of proglottid ( Fig. 2D View FIGURE 2 ). Two pairs of osmoregulatory ducts, 1 dorsal, 1 ventral. Detached gravid proglottids 1.53– 2.11 mm (2 mm ± 0.2 mm, 8) long, 300–450 (371 ± 59, 8) wide. Unembryonated eggs subspherical, 28–38 (31 ± 3, 4, 20) long, 20–28 (23 ± 2, 4, 20) wide ( Fig. 2G View FIGURE 2 ).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.