Altmanella, Fend, 2009

Fend, En. V., 2009, An evaluation of the genus Kincaidiana Altman, 1936, with the designation of Altmanella n. gen. (Annelida, Clitellata, Lumbriculidae), Zootaxa 2077, pp. 1-30 : 6-7

Altmanella n. gen.

Diagnosis. Small worms without a proboscis. Dorsal pharyngeal pad present. All chaetae simple-pointed. No lateral blood vessels in posterior segments. First pair of nephridia pre-clitellar, on 6/7. A single testicular segment, with testes paired in VIII or IX, ovaries paired in IX or X. Male pores one pair, behind ventral chaetae in VIII or IX; spermathecal pores one pair, behind ventral chaetae in the first post-atrial segment. Atria elongate and tubular to petiolate; male pores either on short porophores or on penes formed by extrusion of elongated lining cells from a muscular penial structure. A single pair of male funnels on the posterior septum of the atrial segment; one posteriorly-directed vas deferens per atrium; vasa deferentia do not penetrate posterior septum. Female pores on chaetal lines at posterior septum of first post-atrial segment. Spermathecal ducts narrow-elongate; ducts may terminate in vestibules; spermathecal ampullae globular to ovate with large, vacuolated cells entally.

Type species. Altmanella freidris ( Cook, 1966) n. comb.

Other species. Altmanella idahoensis n. sp., Altmanella lenati n. sp.

Etymology. The genus is named for L.C. Altman, whose early work (including the description of Kincaidiana ) provided the basis for subsequent studies of northwestern Nearctic oligochaetes.

Remarks. Altmanella species differ from Kincaidiana s. str. in many respects, and should be assigned to a separate genus. All Altmanella species are small worms ( Figs. 2A–B, 13A), and lack a proboscis; chaetae in anterior segments are not enlarged or bifid, pre-clitellar nephridia are present on 6/7, and lateral blood vessels are absent from posterior segments. Altmanella has a single pair of spermathecae in the first post-atrial segment (a common condition in lumbriculid genera), but spermathecae are absent in the less-common atrial and second postatrial segments.

In addition to differences in arrangement, there are basic structural differences between the reproductive organs of Altmanella and Kincaidiana . The western Altmanella species have petiolate atria, and penes are formed by extrusion of elongated lining cells from a distinct penial structure ( Figs. 6J, 10L–M). The single eastern species has tubular atria and male ducts terminating in short porophores ( Fig. 15I). None has pendant penes within an eversible sac ( Fig. 2H). Altmanella has narrow spermathecal ducts ( Figs. 4, 8, 14), in contrast to the thick ducts seen in Kincaidiana ( Fig. 1E). The spermathecal ampullae of Altmanella are globular, with large cells (apparently with sorptive vacuoles) in the ental portion, in contrast to the narrow, more uniform ampullar walls of Kincaidiana . The unusual extension of atrial muscle onto the vasa deferentia is seen only in Kincaidiana .

See also Remarks at A. freidris .