This paper documents the publications of the American Malacological Society, and its predecessor, the American Malacological Union, from 1931 through 2007. Information on the dates of publication is included, based primarily on library receipt records. Several publications were erroneously dated as to year, which has resulted in new taxa described in those publications, as well as abstracts and articles, being attributed to the wrong year.

Spermatozeugmata, not to be confused with spermatophores, that also transfer sperm, are compound structures (parasperms with attached eusperms) known only in certain “mesogastropods”: Loxonematoidea? (Abyssochrysidae), Littorinoidea (Littorinidae), Triphoroidea (Triphoridae and Cerithiopsidae), Tonnoidea (Ranellidae), Janthinoidea (Epitoniidae and Janthinidae), and doubtfully Cypraeoidea (Cypraeidae). This pattern of taxonomic occurrence does not match that of any other character known, their morphology is diverse, and it is concluded that the spermatozeugmata in these taxa are not all homologous and that, like spermatophores, they have evolved repeatedly. Littorinid spermatozeugmata have frequently been studied after fixation and shrinkage of the parasperms (“nurse cells”), during which the eusperms drop off. Spermatozeugmata are not a synapomorphy linking the Triphoroidea and Janthinoidea. Records of spermatophores (except in the “pulmonate” suborder Stylommatophora) since Robertson (1989) are updated.

The neogastropod family Muricidae includes a diverse set of radular bauplane, including a beaked, three-dimensional form, a flattened-pentacusped form, and a third “dagger” type in which the central rachidian cusp is massive and elongate. Examination of the radular ontogenies of representatives of five muricid subfamilies reveals that several species undergo changes in radular form during ontogeny on a scale comparable to the evolutionary differences between higher taxa. The species Concholepas concholepas (Bruguière, 1789) (Rapaninae) and Trophon geversianus (Pallas, 1774) (Trophoninae) begin ontogeny with a three-dimensional rachidian characteristic of the Ocenebrinae or Muricopsinae but end with the dagger rachidian typical of their respective subfamilies. Young individuals of Vitularia salebrosa (King and Broderip, 1832) (Muricopsinae?) also have a three-dimensional rachidian but shift to a double-dagger morphology by adulthood. Chicoreus (Phyllonotus) pomum (Gmelin, 1791) (Muricinae) has a typical flattened muricine rachidian as an adult but possesses a “buccinoid”-like rachidian just after hatching. Urosalpinx cinerea (Say, 1822) (Ocenebrinae), was unique among the species examined in exhibiting no ontogenetic changes in radular form. The occurrence of two radular bauplane within the same individual snail during ontogeny suggests great potential for rapid, convergent evolution of adult features through simple changes in developmental timing. A three-dimensional rachidian, for example, could be retained into adulthood through paedomorphosis in any lineage possessing the three-dimensional-to-dagger ontogeny. Systematic assignments of muricids based solely on radular features should be reexamined.

Phylogenetic reconstructions are still lacking for many molluscan groups, making evolutionary inferences much weaker. The genera Cotonopsis Olsson, 1942 and Cosmioconcha Dall, 1913 are part of the so called Strombina group, and as such have been used as models to study patterns of speciation and extinction brought about by the rise of the Central American gateway. Earlier work, based on a few species of each genus, pointed towards a very close relationship of these genera, which prompted a complete cladistic analysis, including all species of both genera to evaluate the level of relationship. Cladistic analyses based on shell morphology support the monophyly of the group composed by Cotonopsis Cosmioconcha. Cotonopsis as currently defined is paraphyletic and includes Cosmioconcha. Cotonopsis (Turrina) keeps its constituency and may retain its subgeneric status. Cotonopsis sensu stricto should be redefined to include part of Cosmioconcha. Cosmioconcha should be subdivided into two groups. One of these groups should be included in Cotonopsis sensu stricto. The second group should be given subgeneric status. Cotonopsis has a much earlier time of origination and most probably derives from Cosmioconcha. Obtained results give support to some of the evolutionary patterns documented earlier for the Neogene molluscan faunas of tropical America and contribute to a better understanding of the Plio-Pleistocene divergence and turnover events related to the rise of the Panamanian land bridge.

A detailed morphological study was performed on the following taxa normally considered to belong to the family Pseudolividae: (1) Zemira australis (Sowerby, 1833) from Australia; (2) Fulmentum ancilla (Hanley, 1859) from South Africa; and (3) Melapium lineatum (Lamarck, 1822) from South Africa. Two additional species of pseudolivids, Benthobia atafona Simone, 2003 and B. complexirhyna Simone, 2003, from Brazil and New Zealand respectively, are considered. Two other muricoideans are included in this study: (1) Nassodonta dorri (Watteblet, 1886) [Nassariidae] from Vietnam (morphological study also included) and (2) Siratus senegalensis (Gmelin, 1791) (Muricidae) from Brazil (published elsewhere). Both species are outgroups, but operationally included as part of the ingroup in order to test the monophyly of the Pseudolividae. In particular, N. dorri has a shell very similar to a pseudolivid. A complete taxonomical and morphological treatment of each species is included, as a scenario of a formal phylogenetic analysis. Additional outgroups considered include a pool of Tonnoidea (the root) and Conoidea. The cladogram is: (Tonnoidea (Conoidea ((Benthobia atafona–B. complexirhyna) (Nassodonta dorri (Zemira australis (Fulmentum ancilla (Siratus senegalensis–Melapium lineatum))))))). Analyses of each important character and of the cladogram were performed. Some of the conclusions include that the family Pseudolividae, as presently understood, is polyphyletic, as it would include a nassariid (N. dorri) and a muricid (S. senegalensis).

The dioecious snail Cerithidea rhizophorarum (Adams, 1855) is distributed along the coasts of the western Pacific up to the Tohoku district, northern Honshu, Japan. It inhabits reed grasslands and mangrove forests with Kandelia candel and Hibiscus hamabo trees on a mud flat located at the mouth of Atagogawa River in Kiire. Studies of mating and tree climbing behaviors of the species were conducted at this site from April 2000 to May 2003. Mating behavior was observed in July and August 2002. The time of commencement, termination, and duration were recorded for each copulation. The peak of matings during daytime was seen at 1 to 2, and 5 hours before the lowest tide and during nighttime, between 1 hour before and after lowest tide. However, mating rarely occurred on cloudy days. Climbing behavior was observed in an area of 100 square meters where only K. candel trees existed. The number of snails on trees was counted, and daily activity of the snails on trees was monitored in summer and winter, hourly throughout the day. The snails were mainly found on mud from spring to summer but frequently climbed up the tree at particular times during summer. Most individuals were on trees and motionless during winter.

The mechanisms for variation in the primary and apparent sex ratios, from both theoretical and empirical perspectives, are reviewed. A series of experiments on the sex ratios and mode of sex determination in the apple snail Pomacea canaliculata (Lamarck, 1822) show that broods have highly variable sex ratios even though the sex ratios of populations are 1:1. I suggest that the mechanism responsible for this pattern is oligogenic sex determination, i.e., sex determination by a small number of genes. Two other molluscan groups, the protandric oysters of the genus Crassostrea Sacco, 1897, and mussels of the genus Mytilus Linnaeus, 1758 also show variable sex ratios. In both cases, the number of genes responsible for the variation appears to be small.

The gastropod genus Alderia (Allman, 1845) (Opisthobranchia: Sacoglossa) contains a rare case of poecilogony, or variable larval development within a species. This paper reviews the alternative larval morphs and dispersal strategies expressed by Alderia spp., and presents new data on larval ecology, environmentally induced changes in development, and rates of metamorphosis for larvae differing in age and life history. Recent morphological and molecular analyses revealed a cryptic poecilogonous species in the previously monotypic genus Alderia. The newly described Alderia willowi Krug et al., 2007 occurs south of Bodega Harbor, California, and was the subject of all prior studies by Krug and co-workers. Unlike its strictly planktotrophic congener Alderia modesta (Lovén, 1844), A. willowi produces either small feeding larvae that have a 30-day pre-competent period or large larvae that need not feed to metamorphose. Individuals can vary the developmental mode of their offspring, with a variable proportion switching from lecithotrophy (prevalent in summer) to planktotrophy in winter or spring; a similar shift is induced in some adults upon transfer to the laboratory. In a second dispersal polymorphism, a variable percentage of lecithotrophic larvae undergo spontaneous metamorphosis within 2 days of hatching, while their siblings disperse until induced to settle by carbohydrate cues from the host algae Vaucheria spp. The percentage of spontaneous metamorphosis is uncorrelated with fecundity and is generally between 15–30%, a possible product of stabilizing selection on this bet-hedging dispersal strategy. Despite their different ages, competent larval morphs produced by alternative developmental pathways are similar in size, swimming behavior, and responses to dissolved settlement cues. However, competent planktotrophic larvae and older lecithotrophic larvae initiated metamorphosis faster after settlement than newly hatched lecithotrophic larvae, suggesting a link between planktonic period and habitat choice. Although rare, poecilogonous species like A. willowi offer special insights into the evolutionary causes and ecological consequences of alternative life histories.

With the aim of integrating the physiology and evolutionary ecology of Lymnaea stagnalis (Linnaeus, 1758), we studied the effects of day length and food availability on the energy budget. Snails were assigned to two different photoperiods and three levels of food availability. The snails were kept individually, and food consumption, growth, and egg production were measured for about 2 months. Snails could nearly compensate for a one-day starvation period by increasing the rate of food-intake. However, food-intake rates did not increase further after a starvation period of 2 days. Growth was well described by the Von Bertalanffy growth equation. The ultimate size of snails kept under medium-day conditions (MD; light:dark = 12:12 h) was not affected by food availability. By contrast, the ultimate size of snails kept under long-day conditions (LD; light:dark = 16:8 h) depended on food availability; those fed the lowest quantities grow the least. Dry-weight densities (dry weight/wet weight) of MD snails were considerably above those of LD snails. In MD snails, food availability did not appreciably affect dry-weight density. By contrast, in LD snails, dry-weight density decreased with decreasing food availability. The reproductive output of LD snails declined with declining food availability, but was 2 to 4 times that of MD snails. The difference in reproductive output was largely accounted for by the difference in stored energy, i.e. dry-weight density. To gauge the extent to which the conclusions from our laboratory work applied to free-living snails, a field study was conducted. The wild-caught snails' dry-weight density was also lowest in long-day conditions when most eggs were laid. However, the dry-weight densities during medium and short days were lower than the dry-weight densities of laboratory animals under LD conditions. Thus, in the field, snails stored less energy than in the laboratory.

Phally polymorphism, whereby some individuals in a hermaphroditic species have a complete functional penis (euphally), whereas others lack a penis (aphally) or have a reduced, non-functional penis (hemiphally), has evolved many times in pulmonate gastropods. Since the discovery of apophallation (penis amputation) in Ariolimax Mörch, 1860, aphallates in this genus have been attributed to apophallation. In laboratory studies in Ariolimax (Ariolimax) buttoni (Pilsbry and Vanatta, 1896), we found aphally in juveniles as well as in individuals reared in isolation to adulthood, demonstrating that the aphallate condition is not always due to apophallation. Some aphallate individuals reared in isolation from hatching produced eggs and viable hatchlings, providing the first demonstration of uniparental reproduction in this species. Egg-to-egg generation time in laboratory-reared individuals ranged from 10 months to more than 24 months. Anatomical data also elucidate the reproductive cycle of this species. Four reproductive states have been identified by the appearance of the reproductive system. Spring and early summer populations consist of individuals in the immature and intermediate reproductive states. The hypertrophied state was found from autumn until early spring. Egg-laying occurred in the laboratory in the fall and winter. Copulation consists of unilateral or simultaneously reciprocal intromissions and occurred in the laboratory between February and September. Very long copulations (more than 7 h) are more frequent than in other species of Ariolimax. Phally polymorphism, uniparental reproduction, and the variation in generation time should play important roles in determining the variance of mating success and the potential for sexual selection in this hermaphroditic species.

The genus Deroceras Rafinesque, 1820 (the largest genus of terrestrial slugs) shows a high diversity of penis morphologies and mating behaviors. The function of most of the appending external and internal penial structures, some of them truly bizarre, is largely unknown. This paper reviews mating behavior and reproduction, based on data on 16 species from the literature and from unpublished observations. I analyze patterns common to all Deroceras species and differences among species. The general mating pattern consists of a long courtship with mutual stroking with a sarcobelum, a sudden penis eversion, and external sperm exchange (copulation). I distinguish also precourtship and withdrawal phases. Sperm exchange is usually very quick but, in a few species, occupies a considerable proportion of the total mating duration. Mutual sperm exchange is the rule. Species differences involve the durations of certain mating phases, presence and nature of initial trail following, nature and intensity of stroking (including the degree of contact with the sarcobelum), aggressiveness of courtship behavior, and the timing of the penial gland eversion. I hypothesize that the radiation of mating behaviors and associated structures has been driven by an arms race resulting from conflicting interests of mating partners over sperm donation and use. This could also have increased the rate of speciation in Deroceras. There are indications of the presence of sperm competition and conflicting interests between mating partners: individuals mate repeatedly, can store and digest sperm, and simultaneously use sperm from different mating partners for fertilization. Some details of mating behavior also indicate conflict. The timing of the penial gland eversion after sperm exchange suggests a manipulation akin to the role of love darts in helicid snails. Finally, some recommendations for studying mating behavior in Deroceras are given.

This review summarizes the present knowledge on the reproductive biology, mating system, sperm competition, sex allocation, and mating conflict in the simultaneously hermaphroditic land snail Arianta arbustorum (Linnaeus, 1758) (Helicidae). Field studies and controlled laboratory experiments indicate that mating is random with respect to shell size. However, subtle effects of inbreeding (reduced hatching success of eggs and viability of juveniles) and outbreeding were found. Individuals of A. arbustorum mate repeatedly with different partners and store viable sperm for more than one year. Spermatophore transfer is highly reciprocal, but the number of sperm they contain (800,000–4,000,000) is not necessarily equal. Snails need 3–4 weeks to replenish their autosperm reserves after a successful copulation. Sperm are monomorphic. However, there is considerable among-population—and to a minor extent—within-population variation in total sperm length. Sperm utilization patterns in double-mated individuals of A. arbustorum revealed striking differences among individuals. There is a huge variation in the structure of the spermatheca, which consists of 2–9 blind tubules. Different lines of evidence suggest that the snails might be able to store and expel sperm stored in single tubules and thus promote a selective fertilization of eggs (cryptic female choice). Maternal investment in eggs is considerable. Snails mated 1, 2, or 3 times showed that irrespective of the number of matings the individuals devoted >95% of the resources into the female function.

Stylommatophoran land snails and slugs generally mate by shell-mounting or face-to-face. Although phylogenetic evidence suggests that the mating position has remained more or less constant throughout the evolution of most lineages, other aspects of mating behavior and associated reproductive characters are highly variable. Along with other gastropods, therefore, stylommatophoran land snails and slugs could be particularly useful in trying to understand sex and sex allocation theory in hermaphrodites. It is often difficult, however, to compare mating behavior in different species because the literature is difficult to access or reports have not been formally published. Here we review studies on the mating behavior of snails and slugs, with the additional aim of creating a central access point and database for use as a resource by those interested in stylommatophoran mating behavior. As we maintain the database, updated versions will be made available at  http://www.molluscs.org.

Some stylommatophoran species, including several helicid snails common to Europe and North America, drive sharp, calcareous darts into their sexual partners prior to copulation. Why any animal would treat a prospective mate in this manner has been the subject of considerable speculation. One widely held belief is that the dart stimulates the partner. Here, I review evidence showing that this hypothesis, along with several others, is almost certainly incorrect. On the other hand, there is strong empirical support for the idea that the dart increases the reproductive fitness of the successful shooter by promoting the survival and utilization of its sperm. How the dart works to produce this effect is an open question; current evidence indicates that it injects a chemical agent into the recipient and that this substance contracts the female tract in such a manner as to facilitate the passage of allosperm to the spermatheca. Although successful dart shooting clearly benefits the shooter, there is little evidence to suggest either a cost or a benefit to the recipient.