The Veliger Larvae and Settlement in the Anaspidean Akera Bullata Helen C
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1 ISSN 0042-3211 -V4X Tur1 tit, ..xAjV VELIGER A Quarterly published by CALIFORNIA MALACOZOOLOGICAL SOCIETY, INC. Berkeley, California R. Stohler (1901-2000), Founding Editor Volume 5 November 16,2012 Number 3 Contents Notes on the Veliger Larvae and Settlement in the Anaspidean Akera bullata Helen C. Marshall 97 The Genus Amarophos Woodring, 1964 (Gastropoda: Buccinoidea) in the Tropical American Neogene, with a Description of Two New Species Bernard Landau and Carlos M. da Silva 102 Population Dynamics of the Freshwater Gastropod Chilina fluminea (Chilinidae), in a Tem- perate Climate Environment Argentina D. E. Gutierrez Gregoric, V. Nunez, and A. Rumi 109 Sublethal Anesthesia of the Southern Pygmy Squid, Idiosepius notoides (Mollusca: Cepha- lopoda) and Its Use in Studying Digestive Lipid Droplets Linda S. Eyster and Lissa M. Van Camp 117 A New Species of Harpa (Gastropoda: Volutoidea) from the Neogene ol the Dominican Re- public: Paleobiogeographical Implications Bernard Landau, Franck Frydman, and Carlos M. da Silva 131 The Mucus of the Mollusk Phyllocaulis boraceiensis: Biochemical Profile and the Search for Microbiological Activity A. R. Toledo-Piza, I. Lebrun, M.R. Franzolin, E. Nakano, O. A. Sant Anna, and T. Kawano 137 Three New Species of Aeolid Nudibranchs (Opisthobranchia) from the Pacific Coast of Mexico, Panama, and the Indopacific, with a Redescription and Redesignation of a Fourth Species Sandra Millen and Alicia Hermosillo 145 Contents — Continued The Veliger (ISSN 0042-3211) is published quarterly by the California Malacozoological So- ciety, Inc., % Santa Barbara Museum of Natural History, 2559 Puesta del Sol Road, Santa Barbara, CA 93105. Periodicals postage paid at Berkeley, CA and additional mailing offices. POSTMASTER: Send address changes to The Veliger, Santa Barbara Museum of Natural His- tory, 2559 Puesta del Sol Road, Santa Barbara, CA 93105. THEVELIGER Scope of the Journal The Veliger is an international, peer-reviewed scientific quarterly published by the California Malaco- zoological Society, a non-profit educational organization. The Veliger is open to original papers pertain- ing to any problem connected with mollusks. Manuscripts are considered on the understanding that their contents have not appeared, or will not appear, elsewhere in substantially the same or abbreviated form. Holotypes of new species must be deposited in a recognized public museum, with catalogue num- bers provided. Even for non-taxonomic papers, placement of voucher specimens in a museum is strongly encouraged and may be required. Editor-in-Chief David R. Lindberg, Museum of Paleontology, 1101 VLSB MC# 4780, University of California, Berkeley, CA 94720-4780, USA Board of Directors Terrence M. 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Send all business correspondence, including subscription orders, membership applications, payments, and changes ofaddress, to: The Veliger, Dr. Henry Chaney, Secretary, Santa Barbara Museum of Natural His- tory, 2559 Puesta del Sol Road, Santa Barbara, CA 93105, USA. Send manuscripts, proofs, books for review, and correspondence regarding editorial matters to: David R. Lindberg, Museum of Paleontology, 1101 VLSB MC# 4780, University of California, Berkeley, CA 94720-4780, USA. ® This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper). a THE VELIGER ©CMS, Inc., 2012 The Veliger 51(3):97-101 (November 16, 2012) Notes on the Veliger Larvae and Settlement in the Anaspidean Akera bulla t HELEN C. MARSHALL Institute of Biological, Environmental and Rural Sciences, Edward Llwyd Building, Aberystwyth University, Ceredigion, SY23 3DA Abstract. Akera bullata is the only member of the Anaspidea to produce lecithotrophic larvae that settle in response to a variety of different substrata. INTRODUCTION 1977; Switzer-Dunlap, 1978; Paige, 1988). Once com- mitted to metamorphosis, the veligers stop crawling In recent years, a great deal of research has been and retract partially or completely into their shell. They conducted on members of the Anaspidea, primarily remain in this state for most of metamorphosis, which investigating settlement and metamorphosis of the "sea can last between 2 and 4 days (Switzer-Dunlap, 1978). hares," the Aplysiidae (Switzer-Dunlap & Hadfield, The velar cilia are shed, and the velum is reabsorbed. 1977; Strenth & Blankenship, 1978; Switzer-Dunlap, The oral tentacles (if present) start to develop at the site 1978; Otsuka et al., 1981; Switzer-Dunlap & Hadfield, of the velum. Crawling is often resumed 1-2 days after 1981; Paige, 1986; Pawlik, 1989; Plaut et al., 1995). the commencement of metamorphosis. The adult heart Akera bullata (Miiller, 1776), however, has been largely then develops, taking over in function from the larval overlooked. Phylogenetic studies have often included heart (Switzer-Dunlap & Hadfield, 1977). During A. bullata to investigate the evolution of the Anaspidea metamorphosis, feeding ceases despite the ability of and Opisthobranchia (Medina & Walsh, 2000; Kluss- the juveniles to rotate the radula and buccal mass mann-Kolb, 2003; Vonnemann et al., 2005; Kluss- (Kriegstein et al., 1974). Approximately 3 days after mann-Kolb et al., 2008); despite this, little is know metamorphosis, the juveniles are able to bite and about its ecology. Populations of A. bullata have been swallow (Kriegstein et al., 1974; Switzer-Dunlap & found throughout the British Isles, and further afield Hadfield, 1977; Switzer-Dunlap, 1978). This process is from the Baltic and North Sea, the Atlantic Ocean, and quicker for B. leachii plei, in which feeding was the Mediterranean Sea: France, Italy, Spain, and Greece (Thompson, 1976; Thompson & Seaward, observed 1 day after metamorphosis (Paige, 1988). 1989). See Switzer-Dunlap & Hadfield (1977) and Switzer- for further details regarding settlement Members of the Anaspidea typically produce plank- Dunlap (1978) cues and the morphological changes that occur during totrophic veligers that spend approximately 1 mo feeding and developing before metamorphosis (Krieg- metamorphosis. June 2004, spawn from A. bullata was stein et al., 1974; Switzer-Dunlap & Hadfield, 1977 During Strenth & Blankenship, 1978; Switzer-Dunlap, 1978 gathered from Langton Hive Point (UK grid reference Otsuka et al., 1981; Paige, 1986, 1988; Pawlik, 1989 SY606814), the Fleet, United Kingdom. The Fleet is a Plaut et al., 1995). Anspideans metamorphose in shallow, saline tidal lagoon covering an area of response to stimuli produced by several different approximately 480 ha. It spans 12.5 km and is boarded species of red, green, brown, and blue-green algae; by Chesil Beach northwest of Portland Bill, Dorset. often, the species inducing metamorphosis is the Langton Hive Point is situated 8 km from the mouth of preferred food of the adult (Kriegstein et al., 1974; the lagoon and is predominantly brackish. Each spawn Switzer-Dunlap & Hadfield, 1977; Strenth & Blanken- mass was placed into a sterile 100-mL glass beaker ship, 1978; Switzer-Dunlap, 1978; Otsuka et al, 1981; containing 50 mL of 0.45-um-filtered sea water. In Paige, 1986, 1988; Pawlik, 1989; Plaut et al., 1995). accordance with Switzer-Dunlap & Hadfield (1981), Phyllaplysia taylori is the exception: this species is penicillin G and streptomycin sulfate were added to unusual in that it undergoes direct development; each beaker after every water change to create a final 1 1 metamorphosis occurs within the egg capsules, thus concentration of 60 ug mL" and 50 ug mL" , respec- juveniles emerge from the egg mass (Bridges, 1975). tively. A 0.41 -urn nylon mesh was floated on the Metamorphosis is similar for all species studied meniscus to prevent the larvae rafting. Parafilm was (Kriegstein et al., 1974; Switzer-Dunlap & Hadfield, used to cover the beakers to prevent evaporation. The Page 98 The Veliger, Vol. 51, No. 3 Table 1 Combinations of substratum, phytoplankton, or both used to investigate veliger settlement. Substratum/ No. Metamorphic Minimum Maximum larval phytoplankton provided replicates success (%)* larval period period (days) Chondrus crispus (C) 25 and 45 48 hr 25 Ulva lactuca (U) 60 and 50 5 days 32 Nemalion helm in tho ides 65 and 40 72 hr 25 Rhinomonas (R) 90 and 35 10 days 38 Tetraselmis (T) 10 and 35 15 days 31 Isochrysis (I) 95 and 75 48 hr 43 Chaetoceros (Ch) 25 and 45 25 days 43 Biofilm (B) 56 and 90 24 hr 17 Control 35 and 25 20 days 32 R + C 100 24 hr 16 R + U 56 72 hr 19 R + B 73 48 hr 16 T + C 43 5 days 13 T+ U 70 5 days 19 T + B 37 24 hr 17 I + C 63 48 hr 19 I + LI 57 24 hr 20 I + B 70 72 hr 21 Ch + C 57 24 hr 17 Ch + U 80 24 hr 24 Ch + B 33 5 days 10 * The two numbers given for metamorphic success are from replicates A and B.