Hydrobiologia

, Volume 428, Issue 1, pp 1–59

New species of Rhynchelmis (Clitellata, Lumbriculidae), with observations on the Nearctic species

Article

DOI: 10.1023/A:1003919312142

Cite this article as:
Fend, S.V. & Brinkhurst, R.O. Hydrobiologia (2000) 428: 1. doi:10.1023/A:1003919312142

Abstract

The Nearctic species of Rhynchelmis (Lumbriculidae) are distinguished from the Palearctic group Rhynchelmis s. str. by longitudinal muscle bands that do not curl inwards. Six new species from western North America support the existence of two major groupings within the Nearctic fauna. Species in Group 1 are distinguished from other Rhynchelmis by large penial bulbs and multiple spermathecal diverticula. Within Group 1, Rhynchelmis yakimorumn. sp.,Rhynchelmis monsserratusn. sp.,Rhynchelmis gustafsonin. sp. and Rhynchelmis utahensisn. sp. differ from the related Rhynchelmis (=Sutroa) rostrata in having short penes and spermathecae with 2 short, lobed diverticula. R. monsserratus is distinguished by a single, median spermatheca, R. gustafsoni has closely appressed, median spermathecae and atria, and R. utahensis differs in structural details of spermathecae and male pores. Rhynchelmis gilensisn. sp. has a single, median spermatheca with unbranched diverticula and distinctive nephridia. Redescription of material from the type localities of both Sutroa alpestris and R. rostrata supports their combination. Group 2, corresponding in part to Rhynchelmoides, is distinguished from Group 1 mostly by characters that are inconsistent or appear plesiomorphic. Within Group 2, Rhynchelmis saxosan. sp. closely resembles Rhynchelmis alaskana, except for the absence of lateral blood vessels in posterior segments and distribution of prostates. Rhynchelmis elrodi and Rhynchelmis glandula consistently differ in presence of ventral glands and have different distributions, so their supposed synonymy is rejected.

ClitellataOligochaetaLumbriculidaeRhynchelmistaxonomy

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  1. 1.U.S. Geological SurveyMenlo ParkU.S.A.
  2. 2.Aquatic Resources CenterFranklinU.S.A.