Ellipsaria Vol. 15 - No. 2 June 2013 Contributed Articles The following articles have been contributed by FMCS members and others with interest in freshwater mollusks. These contributions are incorporated into Ellipsaria without peer review and with minimal editing. The opinions expressed are those of the authors. A Carnivorous Aquatic Gastropod in the Pet Trade in North America: the Next Threat to Freshwater Gastropods? Arthur E. Bogan and Eric H. Hanneman North Carolina State Museum of Natural Sciences, 11 West Jones, St. Raleigh, NC 27601 North America has been subject to a wide variety of alien species being introduced both actively and passively into our freshwaters. Some are food items introduced intentionally, such as the Asian Clam (Corbicula fluminea), while others are introduced by accident, such as the Zebra Mussel (Dreissena polymorpha) and the New Zealand Mudsnail (Potamopyrgus antipodarum). Both of the species have rapidly become major invasive pest species. Another species that has been in the aquarium trade in the United States since about 2007 that may become a major pest is the predatory Assassin Snail (Clea helena). This species also goes by the names Snail Eating Snail, Killer Snail, or Bumble Bee Snail. It is sold in the aquarium trade as a biological means to control aquaria overrun by other snails including Physa sp., Ramshorn Snails (Planorbella sp. or Helisoma sp.) and the introduced Livebearing Trumpet Snail, also known as the Malaysian Trumpet Snail, Red-rimmed Melania (Melanoides tuberculata). Livebearing Trumpet Snails are often moved around on aquatic vegetation in the aquarium trade and easily become a major pest in aquaria. Assassin Snails will also eat introduced Mystery Snails (Cipangopaludina sp.). Clea helena (Meder in Philippi, 1847), also listed as Clea (Anentome) helena and Anentome helena, is one of six species in the genus Clea reported from Malaysia and Indonesia, Thailand, and Laos was originally described from Java (Van Benthem Jutting 1929; 1959; Brandt 1974). Clea helena is a member of the predominately marine gastropod family Buccinidae and is reported not to be restricted to running water and is found in lakes and ponds (Brandt 1974). The predominate native food of the Assassin Snail is decaying animals, live worms and snails (Brandt 1974). Reports from aquarists indicate it also consumes fish eggs and attacks shrimp. [See also Wikipedia http://en.wikipedia.org/wiki/Clea_helena [Accessed 6 March 2013]. Clea helena reaches a shell length of 18-28 mm, the shell is elongate conical, ranging in color from yellow or straw colored to brown, uniform colored or with one to three brown to black spiral bands, shell with axial ribs and six to eight whorls. Aperture is large and is about two thirds of the shell length, with a basal siphonal Figure 1. Clea canal (Brandt 1974). This species is reported to be most active at night, lays clear helena shell soft eggs, one egg laid every 10 days or so. Eggs take about three weeks to hatch (NCSM 83256) and four or more weeks to mature to adulthood. In this species, the sexes are purchased in a reported as separate. shop in Wake Use of the Assassin Snail is reported in European literature as a successful County, North biological agent for control of other harmful snails in aquaria (e.g. Butot 1954; Van Carolina. Total Neil 1954; Behrendt 2009; Schiffbauer 2009; Smid 2009). We have not seen any shell length is articles in the literature for North America. Mienis (2011) cautioned about the wide 14.4 mm. sale of the Assassin Snail throughout Israel and the potential for devastation of the native aquatic gastropod fauna. The Invasive Species Compendium http://www.cabi.org/isc/?compid=5&dsid=108187&loadmodule=datasheet&page=481&site=144 lists Clea helena but notes “It has not been reported in the literature as an invasive species but is potentially a threat in warmer regions for a number of reasons.” They continue with “it is able to 18 Ellipsaria Vol. 15 - No. 2 June 2013 reproduce under aquarium conditions. Finally, under aquarium conditions at least, it will readily consume small aquatic snail species that it would not encounter in its natural habitat, and there is no reason to suppose it would be any less predatory if introduced populations became established outside the species’ natural range.” An aquarist observed Clea helena had been kept in aquaria outside over the winter in the Seattle area and the snails survived. This does not bode well for this species being too limited by climate in the United States. Literature Cited Behrendt, A. 2009. [Anentome helena. A flexible predator amongst freshwater snails.] Anentome helena Ein flexibler Raeuber unter den Suesswasserschnecken. Datz 62(9):35-37. Brandt, R. A. 1974. The non-marine aquatic Mollusca of Thailand. Archiv für Molluskenkunde 105(14):1-423, plates 1-30. Butot, L.J.M. 1954. Over een zoetwater roofslak. Anentome helena (v.d. B.) Gastr.-Prosobr. Penggemar Alam 34(3-4):108-115. Mienis, H.K. 2011. Will the Uncontrolled Sale of the Snail-eating Gastropod Anentome helena in Aquarium Shops in Israel Result in Another Disaster for Israel's Native Freshwater Mollusc Fauna? Ellipsaria 13(3):10-11. Schiffbauer, J. 2009. [Anentome helena (Meder, 1847) - the assassin snail.] Anentome helena (Meder, 1847) - die Helena-Raubschnecke. Arthropoda 17(1):60-65. Smid, G.R. 2009. [Biological control of harmful snails in aquaria using 'keong penumbuh': Anentome helena or Clea helena.] Biologische bestrijding van schadelijke slakken in aquaria met 'keong penumbuh': Anentome helena of Clea helena. Aquarium (Hilversum) 79(2):22-25. Van Benthem Jutting, W.S.S. 1929. Appendix 1. A list of the land and freshwater Mollusca from Java. Treubia 11(1):1-13. Van Benthem Jutting, W.S.S. 1959. Catalogue of the non-marine Mollusca of Sumatra and its satellite islands. Beaufortia: Series of miscellaneous publications. Zoological Museum-Amsterdam Number 83: 41-191, plates 1, 2, 1 map. Van Niel, J.P. 1954. Anentome helena (v. d. B.) in een aquarium. Penggemar Alam 34(3-4):107. Laboratory Trials Show flutedshell (Lasmigona costata) Transform on Several Fishes Jade Thomason1, Mark Hove1, Bernard Sietman2, Matt Berg3, Stephanie Anderson3, Samantha Bump2, Ashley Lindeman2, Nicole Ward2, Scott Morley3, Shepard Berreth-Doran3, and Clay Poeschl3 1 Dept. Fish., Wild., & Cons Biol., Univ. of Minnesota (UMN), 1980 Folwell Ave., St. Paul 55108 Minnesota Department of Natural Resources (MN DNR), 500 Lafayette Rd., St. Paul 55155 3 Grantsburg High School (GHS), 480 East James Ave., Grantsburg, WI 54840 2 The flutedshell (Lasmigona costata) is a species of special concern in Minnesota and life history information is needed to improve conservation efforts. We followed standard protocol to identify suitable glochidia hosts (Fritts et al., 2012). Forty-nine fish species were infested with flutedshell glochidia and 37 species facilitated metamorphosis (Table 1). Juveniles released from suitable hosts between 9-31 days after inoculation, and unsuitable hosts sloughed glochidia between 2-17 days. Creek chub, green sunfish, rainbow darter, white sucker, and yellow perch produced particularly high numbers of juveniles. Laboratory trials suggest flutedshell is a host generalist but there have been very few observations from natural conditions to verify this hypothesis. Previous studies have reported brown bullhead, bowfin, northern pike, northern studfish, some minnows, suckers, sculpins, several sunfishes, and perches as suitable laboratory hosts for flutedshell (Lefevre and Curtis 1912, Luo 1993, Hove et al., 1994, Watters et al., 1998), many of which were confirmed in our study. Weiss and Layzer (1995) found flutedshell naturally infesting gizzard shad and river redhorse. As a future part of this study, we hope to recover juvenile flutedshell from naturally infested fishes. 19