Stillabothrium davidcynthiaorum Daigler et Reyda 2016, sp. n.
Creators: name: Reyda, Florian B.
name: Healy, Claire J.
name: Haslach, Andrew R.
name: Ruhnke, Timothy R.
name: Aprill, Tara L.
name: Bergman, Michael P.
name: Daigler, Andrew L.
name: Dedrick, Elsie A.
name: Delgado, Illari
name: Forti, Kathryn S.
name: Herzog, Kaylee S.
name: Russell, Rebecca S.
name: Willsey, Danielle D.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Platyhelminthes
Cestoda
Rhinebothriidea
Escherbothriidae
Stillabothrium
Stillabothrium davidcynthiaorum

description: <i>Stillabothrium davidcynthiaorum</i> Daigler et Reyda sp. n. Figs. 1, 4, 5, 16B ZooBank number for species: urn:lsid:zoobank.org:act: D36AE2D9-C4A6-4C4D-8F82-E9C0FAF1F92C <b>Description</b> (based on whole mounts of 32 complete mature worms, cross sections of 1 strobila and longitudinal sections of 1 scolex and 3 scoleces prepared for SEM): Worms (Fig. 4A) euapolytic, acraspedote, 0.62–2.59 mm (1.29 ± 0.57; n = 30) long, greatest width 195–561 (332 ± 84.7; n = 32) at level of scolex; 4–10 (7 ± 2.1; n = 32) proglottids per worm. Cephalic peduncle lacking; darkly staining germinative zone 12–40 (22 ± 7; n = 29) long. Scolex (Fig. 4B) consisting of scolex proper bearing 4 stalked bothridia. Stalks 25–100 (52 ± 20; n = 23) long by 27–83 (55 ± 17; n = 23) wide, attached slightly posterior to middle of bothridia. Bothridia (Fig. 4B) varying in shape with degree of contraction, from shallowly-deltoid (Fig. 5A) to deeply-deltoid (Figs. 4B, 5B), facially loculated, 72–175 (108 ± 26; n = 20) long by 140–325 (202 ± 42; n = 32) wide; bothridial margins with thin rim. Anterior region of bothridia (Fig. 4B) with 3 (n = 28) horizontally oriented loculi (i.e. loculi wider than long) with 2 complete transverse septa and one partial medial longitudinal septum. Anteriormost loculus 22–49 (31 ± 8; n = 18) long and 37– 78 (47 ± 9; n = 25) wide. Posterior region of bothridia with 10 (n = 30) nonmedial longitudinal septa dividing bothridia into 11 primary loculi longer than wide, outermost primary loculi on each side subdivided by 2, or occasionally 3 (2.04 ± 0.2; n = 24) relatively short marginal septa into 3–4 small subloculi; longitudinal septa of posterior region not overlapping transverse septa of anterior region. Loculi and septa of distal bothridial surfaces (Fig. 5C) bearing capilliform filitriches and coniform spinitriches. Proximal bothridial rim (Fig. 5D) bearing capilliform filitriches greater in length than those on distal bothridial surfaces (Fig. 5C). Proximal bothridial surfaces (Fig. 5D,E) away from rim bearing acicular filitriches and coniform spinitriches. Isolated cilia observed on proximal bothridial surfaces. Bothridial stalks (Fig. 5F) bearing capilliform filitriches and coniform spinitriches; strobila (Fig. 5G) bearing capilliform filitriches only. Strobila with 1–5 (2.6 ± 0.9; n = 32) proglottids wider than long followed by 2–8 (4.1 ± 1.8; n = 32) proglottids longer than wide. Strobila widest at terminal proglottid; terminal proglottid 255–790 (438 ± 124; n = 31) long by 60–144 (108 ± 18; n = 32) wide; genital pore located 42–54% (48 ± 3.5; n = 21) of proglottid length from proglottid posterior margin. Immature proglottids 3–9 (5.5 ± 1.9; n = 32) in number. Mature proglottids 1–3 (1.2 ± 0.5; n = 32) in number, including 0–2 (0.2 ± 0.5; n = 32) vas deferens-mature proglottids. Testes in mature proglottids 11–21 (16 ± 3; n = 32) in total number, 1 layer deep in cross section, arranged in 2 columns (Fig. 4C); columns extending from anterior margin of proglottid to anterior margin of cirrus sac, 13–49 (25 ± 8; n = 32) long by 24–50 (35 ± 6; n = 32) wide. Vas deferens coiled, entering anterior margin of cirrus sac, extending from level of ovarian isthmus to overlap posteriormost testes. Cirrus sac thin-walled, oval, extending medially to near midline of proglottid; cirrus sac in terminal mature proglottid 18–35 (26 ± 5; n = 26) long by 24–38 (31 ± 4; n = 24) wide; cirrus sac in vas deferens-mature proglottids 32–45 (39 ± 5; n = 5) long by 33–46 (40 ± 5; n = 5) wide. Cirrus spinitriches present. Vagina (Fig. 4C) thick-walled, weakly sinuous, somewhat overlapping anterior margin of cirrus sac (Fig. 16B), extending along midline of proglottid from ootype region to anterior margin of cirrus sac, then laterally to open into genital atrium anterior to cirrus sac; vaginal sphincter absent. Seminal receptacle present. Ovary near posterior end of proglottid, H-shaped in frontal view, tetralobed in cross section; ovarian lobes asymmetrical; poral and aporal ovarian lobes in terminal mature proglottids 75–254 (144 ± 40; n = 24) and 75–272 (152 ± 42; n = 24) long, respectively. Poral and aporal ovarian lobes in vas deferens-mature proglottids 145–269 (198 ± 48; n = 5) and 152–270 (206 ± 46; n = 5) long, respectively. Maximum width of ovary 39–139 (65 ± 21; n = 32). Ovarian isthmus near midpoint of ovary; poral lobe of ovary stopping 19–85 (31 ± 16; n = 28) short of genital pore. Mehlis’ gland well posterior to ovarian isthmus, 12–43 (27 ± 8; n = 29) long by 10–35 (20 ±; n = 29) wide. Vitellarium follicular, vitelline follicles arranged in 1 dorsal and 1 ventral column on each side of proglottid; columns extending from anterior to posterior margin of proglottid, interrupted by genital genitalia, and mostly interrupted by ovary (Fig. 4C). Uterus ventral, sacciform, extending from near isthmus of ovary to near anterior margin of proglottid. I n f o r m a l s y n o n y m s: Rhinebothriinae New genus 3 sp. n. 6 of Healy et al. (2009), Caira et al. (2014), Ruhnke et al. (2015), Marques and Caira (2016). T y p e h o s t: <i>Himantura heterura</i> (Bleeker), dwarf whipray (Myliobatiformes: Dasyatidae). A d d i t i o n a l h o s t s: <i>Himantura macrura</i>, <i>Himantura gerrardi</i>, <i>Himantura uarnak</i> 3. Ty p e l o c a l i t y: South China Sea off Sematan (01°48’15''N; 109°46'47''E), Sarawak, Malaysian Borneo (hosts BO-19, BO-141, BO-170). A d d i t i o n a l l o c a l i t i e s: South China Sea off Mukah (02°53'52''N; 112°05'44''E), Sarawak, Malaysian Borneo (BO-47, BO-66, BO-67, BO-237, BO-238). Java Sea off Kalapseban (03°14'30''S; 112°54'52''E), Central Kalimantan, Indonesian Borneo (KA-99, KA-111). Java Sea off Singkawang (00°55'06''N; 108°58'60''E), West Kalimantan, Indonesian Borneo (KA-145). S i t e o f i n f e c t i o n: Spiral intestine. Ty p e m a t e r i a l: Holotype MZUM (P) No. 2016.9 (H). Paratypes: IPCAS No. C-739; LRP Nos. 8986–8991; 9038–9062 (including molecular vouchers, cross sections and SEM specimens); MZB Nos. Ca200–Ca201; MZUM (P) No. 2016.10 (P); SBC No. P-00070; USNM Nos. 1420461–1420466. E t y m o l o g y: This species is named in honour of David and Cynthia Daigler, parents of A.L. Daigler, for their support of his education and his interests. <b>Remarks.</b> <i>Stillabothrium davidcynthiaorum</i> sp. n. can be distinguished from <i>S. ashleyae</i> in its possession of 10, rather than eight, longitudinal septa on the central posterior region of the bothridium. While <i>S. davidcynthiaorum</i> and <i>S. ashleyae</i> are similar in possessing a range of 2–3 marginal septa on both of the lateral sides on the posterior region of the bothridium, the former differs from the latter in mean number (2.04 [n = 24] <i>vs</i> 2.94 [n = 16]). In the present study we report specimens of <i>S. davidcynthiaorum</i> from potentially four species of <i>Himantura</i>, <i>H. heterura</i>, <i>H</i>. <i>macrura</i>, <i>H</i>. <i>gerrardi</i> and <i>H. uarnak</i> 3. Although <i>S. davidcynthiaorum</i> was encountered in four potential species of <i>Himantura,</i> we point out having encountered specimens morphologically similar to <i>S. davidcynthiaorum</i> in four additional species of <i>Himantura</i> that were examined during the survey work in Borneo, including <i>Himantura</i> cf. <i>pastinacoides</i> (BO-61, BO-168), <i>H. undulata</i> (BO-24), <i>U. lobistomus</i> (BO-247) and <i>H. oxyrhyncha</i> (KA-252). Further examination of the <i>Stillabothrium</i> specimens from those additional four species of <i>Himantura</i> is needed, in combination with DNA sequence data, to establish whether those cestodes are conspecific with <i>S. davidcynthiaorum</i> or represent an undescribed species of the genus. Seven specimens of <i>S. davidcynthiaorum</i> were included in the phylogenetic analysis (Fig. 1, Table 1). One of the seven specimens (LRP 3926) was previously included in the analysis provided by Healy et al. (2009) as ‘Rhinebothriinae New genus 3 sp. n. 6’.
description: Published as part of <i>Reyda, Florian B., Healy, Claire J., Haslach, Andrew R., Ruhnke, Timothy R., Aprill, Tara L., Bergman, Michael P., Daigler, Andrew L., Dedrick, Elsie A., Delgado, Illari, Forti, Kathryn S., Herzog, Kaylee S., Russell, Rebecca S. &amp; Willsey, Danielle D., 2016, A new genus of rhinebothriidean cestodes from batoid elasmobranchs, with the description of five new species and two new combinations, pp. 1-28 in Folia Parasitologica (038) (038) 63 (38)</i> on pages 8-11, DOI: 10.14411/fp.2016.038, http://zenodo.org/record/8143428
description: {"references": ["HEALY C. J., CAIRA J. N., JENSEN K., WEBSTER B. L., LITTLE- WOOD, D. T. J. 2009: Proposal for a new tapeworm order, Rhinebothriidea. Int. J. Parasitol. 39: 497 - 511.", "RUHNKE T. R., CAIRA J. N., COX A. 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: 051 - 081.", "MARQUES F. P. L., CAIRA J. N. 2016: Pararhinebothroides - neither the sister taxon of Rhinebothroides nor a valid genus. J. Parasi- tol. 102: 249 - 259."]}