第 31 卷 增刊 水 生 生 物 学 报 Vol.31, Suppl. 2007 年 12 月 ACTA HYDROBIOLOGICA SINICA Dec., 2007 A Survey of Freshwater Annelids in the Peruvian Amazon, South America Daniel H. Shain 1* , Maria I. Aldea Guevara 1 , Alfonso L. Coral 1 , William G. R. Crampton 2 & James S. Albert 2 1 Biology Department, Rutgers The State University of New Jersey, Camden, NJ 08102; 2 Department of Zoology, University of Florida, Gainesville, FL 32611. (*Author for Correspondance: E-mail: dshain@camden.rutgers.edu) Key words: clitellate, leech, glossiphoniid, oligochaete, Pacaya River Abstract A floating meadow habitat within the Pacaya-Samiria National Reserve (Loreto, Peru, South America) was sampled for annelids during September, 2002 as part of a multidisciplinary effort aimed at documenting aquatic animal fauna in the Peruvian Amazon River basin. Among 447 annelid specimens collected, at least seven species were represented, six of which were leeches (Hirudinea). These included predaceous (i.e., Helobdella sp., Helobdella striata) and sanguivorous (i.e., Haementeria depressa, Haementeria maculata) glossiphoniids, a new Ozobranchid (Bogabdella sp.) and one Semiscolecidae (Semiscolex similis). Only one oligochaete species (Allonais inaequalis) was collected. With few exceptions, annelid specimens were found along the periphery of floating vegetation, within one meter below the waterline. Introduction South America and its peripheral coastline support a full spectrum of marine and freshwater annelids. South American polychaetes have been well described and are frequently used as bioindicators (e.g. Amaral et al., 1998), but relatively few descriptions are available for freshwater and terrestrial annelids (Christoffersen, 2006), particularly leeches (Hirudinea). Ringulet (1976) has provided the most comprehensive species list of South American leeches, recognizing four major subregions: (1) tropical, (2) temperate, including most of Argentina and southern Brazil, (3) Andes, ranging from Chile to Colombia, and (4) Chilean, near Valdivia and the adjacent part of Argentina. With few exceptions, most South American leeches appear to be endemic, with minor elements represented from North America (Diestecostoma, Oxyptychus), Africa (Alboglossiphonia) and Australa- sia (e.g., Bogabdella, Ornithobdella) (Sawyer, 1986). The dominant freshwater leeches in South America are predaceous Semiscolecidae (e.g. Semiscolex) that have lost their jaws and teeth, and numerous glossiphoniids (e.g. Haementeria, Helobdella). The various Haementeria species have adapted mecha- nisms for sucking blood of fish, amphibians, reptiles and mammals. Published studies of annelid fauna are limited within the Amazon River watershed. As part of a multidisciplinary effort aimed at documenting aquatic animal fauna in the Peruvian Amazon basin, we surveyed a region of the Pacaya-Samiria National Reserve (Loreto, Peru) in September, 2002. Our collection sites were characterized by abundant floating vegetation, white water and numerous oxbow lagoons. In total, 447 annelid specimens were collected representing at least seven species, most of which inhabited the edges of floating meadows. Materials and methods Sampling methods The survey was conducted between September 15-23,