Dollfusiella Campbell & Beveridge, 1994 (Trypanorhyncha: Eutetrarhynchidae) from elasmobranchs off Borneo, including descriptions of five new species

Abstract

Sampling of a large number of elasmobranchs from coastal waters off Borneo revealed the presence of five new species of Dollfusiella Campbell & Beveridge, 1994 (Trypanorhyncha: Eutetrarhynchidae), namely D. angustiformis n. sp., D. hemispinosa n. sp., D. spinosa n. sp., D. imparispinis n. sp. and D. parva n. sp. Dollfusiella angustiformis n. sp. is described from the spiral intestines of four species of the dasyatid stingray genus Himantura Müller & Henle from both the Indonesian and Malaysian parts of Borneo. All the other species were obtained from Malaysian Borneo. Dollfusiella hemispinosa n. sp. is described from the spiral intestines of three species of Himantura, whereas D. spinosa n. sp. was obtained from several specimens of Pastinachus solocirostris Last, Manjaji & Yearsley (Dasyatidae) as well as from Taeniura lymma 1 (sensu Naylor et al., 2012) (Dasyatidae), Neotrygon kuhlii 2 (sensu Naylor et al., 2012) (Dasyatidae), and Glaucostegus cf. typus (sensu Naylor et al., 2012) (Rhinobatidae). Dollfusiella imparispinis n. sp. is described from the spiral intestine of a single specimen of Chiloscyllium punctatum Müller & Henle (Hemiscyllidae) from the South China Sea off Sarawak, whereas D. parva n. sp. was obtained from several species of Himantura. Specimens of the five novel taxa possess scoleces covered with enlarged microtriches, a morphological characteristic exhibited by several other congeners. However, the new species differ from all congeners by possessing unique patterns of oncotaxy as well as combinations of additional morphological features. The number of valid species within Dollfusiella is increased to 26. For this reason, a key for the species of Dollfusiella is provided. Furthermore, novel information on hosts and geographic distribution is provided for two previously described species of Dollfusiella, D. michiae (Southwell, 1929) and D. spinulifera (Beveridge & Jones, 2000). The latter species differs slightly from the original description and shows a much higher variability with regard to the lengths of the scolex and muscular bulbs and the number of testes. These variable characters subdivided specimens of D. spinulifera into relatively distinct groups. However, the specimens did not differ in their oncotaxy and are considered to represent a single variable species.

Eutetrarhynchid trypanorhynchs (Cestoda) from elasmobranchs off Argentina, including the description of Dollfusiella taminii sp. n. and Parachristianella damiani sp. n., and amended description of Dollfusiella vooremi (São Clemente et Gomes, 1989)

“…It is partially known in 12 species, including 8 species of Dollfusiella and 2 species of Parachristianella (see Whittaker et al 1985, Beveridge et al 2004, Palm 2004, Friggens and Duszynski 2005, Chervy 2009). The presence of spinitriches covering the surface of the scolex peduncle has been used as a diagnostic feature in species of Dollfusiella (see Beveridge et al 2004, Schaeffner andBeveridge 2013c). The scolex peduncle is completely covered with enlarged spinitriches in D. cortezensis, D. imparispinis, D. micracantha, D. ocallaghani, D. parva, D. spinifer, D. spinosa, D. tenuispinis, D. vooremi, and D. taminii, or partially covered (up to the level of the bulbs) in D. angustiformis, D.…”

“…The scolex peduncle is completely covered with enlarged spinitriches in D. cortezensis, D. imparispinis, D. micracantha, D. ocallaghani, D. parva, D. spinifer, D. spinosa, D. tenuispinis, D. vooremi, and D. taminii, or partially covered (up to the level of the bulbs) in D. angustiformis, D. elongata, D. hemispinosa, D. owensi, and D. spinulifera (Beveridge 1990, Beveridge et al 2004, Friggens and Duszynski 2005, Schaeffner and Beveridge 2013c.…”

“…In the key by Schaeffner and Beveridge (2013c), D. vooremi grouped with all the species considered to lack enlarged spinitriches on the scolex surface. The specimens of D. vooremi herein studied showed spinitriches along the entire surface of the scolex peduncle.…”

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Eutetrarhynchid tapeworms currently comprise more than 90 marine species and 2 species reported from rivers in South America (Palm 2004, Campbell and Beveridge 2006, Schaeffner and Beveridge 2012, 2013a,b,c, Haseli 2013, Schaeffner 2014. Among the 17 genera considered valid in the family, Dollfusiella Campbell et , Prochristianella Dollfus, 1946, and Parachristianella Dollfus, 1946 are the most species-rich with 27, 20 and 9 species, respectively.

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“…Dollfusiella was created to include species having a distinctive basal armature and basal swelling, heter-oacanthous metabasal armature with hooks 1 and 1´ not markedly separated, and hook files beginning on the antibothrial surface and terminating on the bothrial surface Beveridge 1994, Beveridge et al 2004). Although species of this genus have been reported worldwide, most species of Dollfusiella have a relatively restricted geographical distribution, with the Australasian region being the most species-rich area (Schaeffner and Beveridge 2013c). Recently, Schaeffner and Beveridge (2013) presented a key for the identification of 26 valid species in the genus.…”