Speckled Pocketbook (Lampsilis streckeri Frierson 1927) 5-Year Review: Summary and Evaluation

摘要

At the time of listing, the only known population of speckled pocketbook was in the Middle Fork Little Red River (MFLRR) from the confluence of Meadow Creek downstream to near Shirley (approxilnately 10 river miles). Surveys in recent years have expanded the distribution of extant populations of speckled pocketbook in the MFLRR extending upstream of the Meadow Creek confluence to the confluence of Little Red Creek (an increase of 53 river miles). Extant populations also have been discovered in 14 river miles of the South Fork, 26 river miles of Archey Fork, two river miles of Turkey Fork, 11 river miles of Beech Fork, and ten miles of Big Creek. Collectively, current extant populations occupy 102 river miles more than at the time of listing and four (Turkey and Beech Forks are considered one population) additional extant metapopulations are known. Characteristics of population demographics (e.g. suitable habitat, male to female sex ratio, etc.) are better understood now than at the time of listing. Primary and secondary suitable host fish have been identified and successful propagation techniques have been developed for the speckled pocketbook. These techniques will be extremely valuable in recovery efforts, should the need to conduct population augmentations or reintroductions arise. Additionally, phylogenetic analysis of the Lampsilis species in Arkansas confirmed taxonomic status of the speckled pocketbook. However, information on the age/size structure of speckled pocketbook populations, the potential lack of gene flow between populations, and status of host fish and their habitat is lacking at this time. These are important population biology issues that need to be determined in order to ensure the continued existence of speckled pocketbook. The U.S. Fish and Wildlife Service with assistance from the Arkansas Game and Fish Commission conducted a comprehensive threats assessment in 2004 and 2005 for the four forks of the upper Little Red River. The assessment identified several new threats (e.g. unrestricted cattle access to streams, eroding stream banks, gravel mining, etc. associated with poor land use practices) that were not previously identified in the five factor analysis. This information has enabled resource agencies to prioritize conservation efforts and areas within the watershed.