Spirosperma

Spirosperma Eisen, 1879 emend. Brinkhurst 1981 (ref. ID; 6972, 7201)

Family Tubificidae (ref. ID; 6651, 7854)

Spirosperma acapillatus (L. & S., 1953) (ref. ID; 6651)
Spirosperma alaskensis (ref. ID; 6972)
Spirosperma apapillatus (Last. & S., 1953) (ref. ID; 7854)
Spirosperma ferox (Eisen, 1879) (ref. ID; 6208) reported year? (ref. ID; 1911, 3955, 4491, 6607)
See; Peloscolex ferox (ref. ID; 6208)
Spirosperma kurenkovi (Soko.) (ref. ID; 6609)
Spirosperma nikolskyi (Lastockin & Sokol'skaya, 1953) (ref. ID; 6972) reported author and year? (ref. ID; 1861)
Spirosperma oregonensis (ref. ID; 6972)
Spirosperma stankovici (Hrabe, 1931) (ref. ID; 6620)
Spirosperma tenuis (Hrabe, 1931) (ref. ID; 6620)
Spirosperma velutinus (Grube, 1879) (ref. ID; 6618, 7201) reported year? (ref. ID; 1911, 3704, 3955)
Syn; Embolocephalus velutinus (Gr.): Holmquist 1979 (ref. ID; 7201); Peloscolex velutinus (Gr.): Cekanovskaya 1962; Brinkhurst and Jamieson 1971 (ref. ID; 7201)
Spirosperma yamaguchii (ref. ID; 6972)

Spirosperma ferox (Eisen, 1879) (ref. ID; 6208) reported year? (ref. ID; 1911, 3955, 4491)

See

Peloscolex ferox (ref. ID; 6208)

Descriptions

This species is indicative of mesotrophic conditions. (ref. ID; 1911, 6607)

Spirosperma nikolskyi (Lastockin & Sokol'skaya, 1953) (ref. ID; 6972) reported author and year? (ref. ID; 1861)

Remarks

Brinkhurst (1981) suggested that Peloscolex kurenkovi Sokol'skaya, Peloscolex oregonensis Brinkhurst, 1965, Embolocephalus alaskensis Holmquist, 1979, and Embolocephalus confusus Holmquist, 1979 (= Peloscolex variegatus Leidy sensu Brinkhurst) were all synonyms of S. nikolskyi, and that they all belonged to the subgenus Embolocephalus rather than to the distinct genus Orientodrilus proposed by Holmquist (1978) for this taxon alone. It was also suggested that the very poorly known Japanese species Tubifex (Peloscolex) nomurai Yamamoto and Okada, 1940 and Peloscolex yamaguchii Brinkhurst, 1971 (Peloscolex sp, of Yamaguchi) maight belong here. Ohtaka (1987) separated S. kurenkovi (with S. alaskensis as a synonym) from S. nikolskyi (with S. oregonensis) on the basis of serration of the hair chaetae and the fact that the spermathecal pores and spermathecal chaetal sacs open separately in the former but jointly in the latter. He also redescribed S. yamaguchii from fresh material (the types are missing) and records 3-6 hairs per bundle and 3-6 pectinates anteriorly, the hairs finely serrate. Postclitellar bundles have 1-4 of each. The ventral bundles of II-VII have 1 bifid and 1 single-pointed chaeta, those from VIII have only 1 bifid chaeta, all of the bifids have the upper teeth a little thinner but longer than the lower. There are spermathecal chaetae in X. The body wall papillation forms rings anteriorly, with naked (sensory according to Ohtaka) bands of about equal width behind the chaetae on each segment. There are also sensory papillae "in circles" (presumably around) each segment. Behind the clitellum, which is naked as usual, the papillation forms the more usual complete covering. The reproductive system resembles that of its congeners, the spermathecal pores and spermathecal chaetal pores are separate, but the spermathecal pores are in front of the chaetal pores here, rather than "latero-frontal" as in S. kurenkovi. Ohtaka therefore regards S. yamaguchii as a distinct species. However, he also describes 3 forms closely related to S. nikolskyi, with the following salient features:

Form 1: 2-4 strongly serrate hairs, 2 or 3 pectinates anteriorly, ventrals II-VI with 1 bifid and 1 simple-pointed chaeta, from VI a single chaeta with upper tooth progressively shorter posteriad, ?spermathecal chaetae.
Form 2: 3-6 finely serrate hairs, 3-5 pectinates, simple-pointed and bifid chaetae to VII, posterior ventrals as above, spermathecal chaetae present.
Form 3: 2-6 finely serrate hairs with 1-4 pectinates, ventrals of II-VII or VIII with simple-pointed and bifid chaetae, otherwise as above.

The distribution of the simple-pointed ventral chaetae in the various specimens forms a gradual progression along the island chain of Japan, the forms with simple-pointed chaetae only in II are from the most northerly locations, and they extend further posteriad until they reach VIII in specimens from Saga in the south. In Chinese specimens, those from Hubei Province have simple-pointed chaetae to IV, the single specimens from Guandong Province to the south has them in II and III only. In previous accounts, Brinkhurst has suggested that variability in position of the spermathecal pores in the radial axis is not of any great significance, although the position in the longitudinal plane may be. Serrations of the hair chaetae are now known to vary intraspecifically within the Naididae and Tubificidae (Chapman and Brinkhurst 1987). These are the primary characters used by Ohtaka to break up the group of taxa associated with S. nikolskyi by Brinkhurst (1981). Ohtaka suggests that there are 3 species within this group, with S. (E.) nomurai as a potential fourth (it is papillate and has spermathecal chaetae) which is yet to be fully described. Now that S. yamaguchii has been redescribed, it seems that the simple-pointed ventral chaetae are found in II-VII, which would have provided a distinction between this and S. nikolskyi apart from the forms related to that taxon by Ohtaka (forms 1-3) in which they can occur all the way back to VIII. (ref. ID; 6972)

Spirosperma velutinus (Grube, 1879) (ref. ID; 6618) reported year? (ref. ID; 1911, 3704, 3955)

Synonym

Embolocephalus velutinus (Gr.): Holmquist 1979 (ref. ID; 7201); Peloscolex velutinus (Gr.): Cekanovskaya 1962; Brinkhurst and Jamieson 1971 (ref. ID; 7201)

Descriptions

This species is indicative of oligotrophic condition. (ref. ID; 1911)