Tellervotrema beringi (Mamaev 1965) (Mamaev, 1965) Gibson & Bray 1982
- Dataset
- Re-evaluation of Tellervotrema katadara (Kuramochi, 2001) Kuramochi, 2009 (Opecoelidae: Plagioporinae) and supplementary morphological data for T. beringi (Mamaev, 1965) Gibson & Bray, 1982 with new host and locality
- Rank
- SPECIES
Classification
- kingdom
- Animalia
- phylum
- Platyhelminthes
- class
- Trematoda
- order
- Plagiorchiida
- family
- Opecoelidae
- genus
- Tellervotrema
- species
- Tellervotrema beringi
discussion
Remarks. The eight studied specimens conform to the diagnosis of the subfamily Plagioporinae and the genus Tellervotrema (macrourid host species = Coryphaenoides longifilis) by Cribb (2005). Kuramochi (2009, p. 30 – 31) gave a rudimentary description of these same specimens (originally identified as T. katadara) providing only a range of body lengths and widths (3.00 – 3.18 mm × 1.16 – 1.35 mm). He even stated that “ … T. katadara may be closely related to T. beringi so far [as] measurements are concerned. ” This material compares well overall with the type description of T. beringi, originally described by Mamaev (1965) as Plagioporus beringi Mamaev, 1965, from the stomach of seven specimens of an unidentified macrourid of the genus Coryphaenoides Gunnerus obtained at 150 – 500 m depths from 30 miles west of the Pribilof Islands, Alaska, and from near Cape Navarin, Russia, in the Bering Sea. When compared to the type description of T. beringi, we noted a few minor morphometric differences: the prepharynx of T. beringi in the original description was more distinct and longer (110 Μm vs 12 – 36 Μm); the pharynx had a slightly larger width (200 vs 112 – 144); the testes were larger (anterior testis: 360 × 780 vs 208 – 264 × 480 – 576; posterior testis: 380 × 750 vs 240 – 304 × 456 – 608); the cirrus pouch had a slightly longer length (600 vs 388 – 476); and the ovary width was slightly smaller (340 vs 376 – 552). Blend et al. (2012) reported individuals of T. beringi in the intestine of the giant grenadier, Albatrossia pectoralis (Gilbert), and Coryphaenoides sp. obtained from depths of 1,530 m and 2,800 m, respectively, in the northeastern Pacific Ocean off Oregon. The eight specimens of T. beringi re-described from C. longifilis here and in Table 3 have a slightly wider body, slightly wider testes and ovary, a longer distance between the ventral sucker and ovary, and larger vitelline follicles and uterus width; however, all other morphometric measurements for the present material along with the six proportions of body lengths (%) and two ratios given in Table 3 compare well to the specimens of T. beringi re-described by Blend et al. (2012). The present material differs slightly from earlier descriptions of T. beringi in the posterior extent of the cirrus pouch relative to the ventral sucker and intestinal bifurcation. Mamaev (1965) reported the cirrus pouch of this species to reach to the posterior margin of the ventral sucker, and Blend et al. (2012) described it to at least overlap 1 / 5 to 3 / 4 the length of the ventral sucker and terminate well posterior to the level of the intestinal bifurcation. In these specimens, the posterior extent of the cirrus pouch just overlaps the anterior margin of the ventral sucker [n = 6, 75 %] — more like T. armstrongi — or extends to the mid-level of the ventral sucker [n = 2; 25 %] — like either T. armstrongi or T. beringi — and it terminates well posterior to the level of the intestinal bifurcation (see Blend et al. 2012). Blend et al. (2012) commented that the testes texture of T. beringi from their material ranged from irregularly indented to deeply lobed; none were smooth as illustrated by Mamaev (1965, Fig. 1) in the original description of this species. There were specimens in this study that possessed smooth testes, and we feel that this observation further supports the possibility of a high degree of plasticity in this feature within species of Tellervotrema; an idea first hypothesized by Blend et al. (2012, Figs. 20 – 23), who on combining their observations of this feature with those of Mamaev (1965), concluded that testes texture of T. beringi can vary from smooth to irregularly indented to deeply lobed. Blend et al. (2012) also observed in T. beringi the characteristic vitellarium gap (separating the paired, isolated vitelline “ bunches ” in the forebody from the remainder of the vitellarium in the hindbody — this gap is characteristic of species of Tellervotrema) at about the level of the posterior margin of the ventral sucker. However, the gap itself was quite variable in number (0, 1 or 2 gaps), symmetry (gaps directly opposite ventral sucker, oblique to ventral sucker, or displaced longitudinally to near level of gonads) and location (near body margin or displaced medially to near midline of worm) (see Blend et al. 2012, Figs. 11 – 16). This same variability in number, symmetry and location of the vitelline gap was seen in the present material of T. beringi from off Japan. Specifically, the gap in the vitelline fields proximate to the ventral sucker varied in number (0, 1 or 2 gaps), symmetry (gaps directly opposite ventral sucker, oblique to ventral sucker, or displaced longitudinally [the highly elongate / lanceolate specimen possessed a large gap in the vitellarium within the posterodextral region of the worm]) and location (near body margin or displaced medially to near midline of worm towards and around ventral sucker).