Caecidotea

Abstract: 1. The blind isopod Caecidotea tridentata is the dominant invertebrate in a simple community of subterranean organisms inhabiting the local, shallow aquifer under Konza Prairie, Kansas, U.S.A. 2. The ecology of this karst aquifer was explored by sieving water from a spring, collecting water samples for analysis, and manipulating sediments and invertebrates in the laboratory. The size frequency distribution was stable and gravid females were present throughout the year, suggesting continuous reproduction. 3. The number of isopods collected per litre was negatively correlated with discharge and the abundance of bacteria, but positively related to the numbers of an amphipod (Bactrurus hubrichti). This may be explained if both the isopods and the amphipods track the saturated zone below the top of the water table; at lower discharge, the top of the water table is closer to the spring outlet. The suspended bacteria wash out in greater numbers with high discharge. 4. When isopods and carbon were added in a pairwise experimental design to sediments collected from the aquifer, the isopods significantly stimulated numbers and activity of planktonic and sedimentary bacteria, while carbon had no effect. This suggests that invertebrates can affect the microbes locally in an aquifer.

Abstract: The Flatwoods Salamander (Ambystoma cingulatum) was listed as a federally threatened species because loss and alteration of adult and larval habitats caused population declines. Current management plans for this species must include maintenance of appropriate larval habitat. However, much of the natural history of this species is poorly known. Our objective was to evaluate the diet of A. cingulatum larvae. We examined stomach contents of 122 larvae collected from Florida and South Carolina. We identified and measured invertebrate prey and estimated biomass using length-mass relationships. Crustaceans, mostly isopods (Caecidotea), amphipods (Crangonyx), cyclopoid copepods, and cladocerans (primarily Simocephalus and other daphnids) were the most abundant prey. Isopods and amphipods also dominated stomach content biomass because of their relatively large size. Stomachs of small A. cingulatum larvae had significantly higher numbers and proportions of cladocerans and smaller numbers and proportions of isopods compared to larger larvae (P < 0.05). Smaller larvae also had significantly lower amounts and proportions of isopod biomass in their guts compared to large larvae (P < 0.05). We found Hedruris siredonis, a parasitic nematode, in ∼11% of stomachs examined; this is a new host record for this parasite. Our results indicate that larvae feed primarily on freshwater crustaceans, particularly isopods, copepods, cladocerans, and amphipods. Management activities that adversely impact freshwater crustacean communities in breeding habitats, such as pesticide use or introductions of predatory fish, could adversely impact remaining populations of this salamander.

Abstract: A new species of Caecidotea, an aquatic isopod crustacean is described from Alchichica crater-lake in the state of Puebla, Oriental Basin, central Mexico. This is the first report of an epigean asellid isopod, with cryptic behavior inhabiting inland saline waters in America. Comparisons made with other co-occurring asellid species in the region show that the species Caecidotea pasquinii differs from the new species in lacking eyes, having different features on the male endopod of pleopod 2, a shorter pereiopod 6, and having elongated uropods. The epigean species Caecidotea communis differs from the new species in having pleopod 4 of the A type pattern of Lewis & Bowman (1981) and 5–8 retinacula on pleopod 1 sympod.

Abstract: Lewis, Julian J., and Thomas E. Bowman. The Subterranean Asellids (Caecidotea) of Illinois (Crustacea: Isopoda: Asellidae). Smithsonian Contributions to Zoology, number 335, 66 pages, 32 figures, 1981.—The state of Illinois is inhabited by 7 species of subterranean asellid isopods of the genus Caecidotea Packard. Three of these are previously known species, C. kendeighi, C. packardi, and C. stygia; 4 are described as new, C. beattyi, C. lesliei, C. meisterae, and C. whitei. Detailed accounts are given of these species and also of C. antricola, which occurs in Missouri counties adjacent to Illinois; C. tridentata, erroneously reported from Illinois; and the epigean C. spatulata, omitted from Williams' 1970 review of North American epigean species. Each account includes a full synonymy, a review of the species' published history, an illustrated description, and discussions of the habitat and geographic range. Three of the species are characterized as phreatobites, inhabitants of the upper layer of groundwater, and are recorded from drain tiles, ditches, springs, and wells. Four species are troglobites, inhabitants of the more open waters of limestone caves or springs in the Ozark Plateaus and Interior Low Plateaus provinces of western and southern Illinois. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SERIES COVER OESICN: The coral Montastrea cavemosa (Linnaeus). Library of Congress Cataloging in Publication Data Lewis, Julian J The subterranean Asellids (Caecidotea) of Illinois. (Smithsonian contributions to zoology ; no. 335) Bibliography: p. 1. Asellidae. 2. Crustacea—Illinois. I. Bowman, Thomas E , joint author. II. Title. III. Series: Smithsonian Institution. Smithsonian contributions to zoology • no 335 QL1.S54 no. 335 (QL444.M34] 591s [595.3'72] 80-606896