Three new species of the carnivorous snail genus Perrottetia Kobelt, 1905 from Thailand (Pulmonata,?Streptaxidae)

Three new species of the streptaxid snail genus Perrottetia are described from north and northeastern Thailand, Perrottetia aquilonaria sp. n., Perrottetia dermapyrrhosa sp. n. and Perrottetia phuphamanensis sp. n. Each species is endemic to a single or a few limestone mountain ranges. The species are characterized by the morphology of their genital organs, as well as by shell characters. Perrottetia aquilonaria sp. n. has a club shaped distal penis and large penial hooks are present and penial papillae cover almost the entire penial hook portion; adjacent areas possess low reticulated folds. Perrottetia dermapyrrhosa sp. n. has a long genital atrium and the penial sheath is about two-thirds of the penis length. Penial hooks are long, scattered and sunken into deep ovate hollows; vaginal hooks are present. Perrottetia phuphamanensis sp. n. has a rounded and protruded shell periphery. The aperture is subcircular, peristome is thick and the second parietal lamella is adjacent to the first parietal lamella; a basal lamella is the smaller than in the other Thai species.     

Introduction to Physidae (Gastropoda: Hygrophila); biogeography, classification, morphology

Physidae, a world-wide family of freshwater snails with about 80 species, are reclassified by progressive characters of the penial complex (the terminal male reproductive system): form and composition of penial sheath and preputium, proportions and structure of penis, presence or absence of penial stylet, site of pore of penial canal, and number and insertions of penial retractor muscles. Observation of these characters, many not recognized previously, has been possible only by the technique used in anesthetizing, fixing, and preserving. These progressive characters are the principal basis of 23 genera, four grades and four clades within the family. The two established subfamilies are divided into seven new tribes including 11 new genera, with diagnoses and lists of species referred to each. Proposed as new are: in Aplexinae, Austrinautini, with Austrinauta g.n. and Caribnautu harryi g.n., nom.nov.; Aplexini; Amecanautini with Amecanauta jaliscoensis g.n., sp.n., Mexinauta g.n., and Mayabina g.n., with M. petenensis, polita, sanctijohannis, tempisquensis spp.nn., Tropinauta sinusdulcensis g.n., sp.n.; and Stenophysini, with Stenophysa spathidophallus sp.n.; in Physinae, Haitiini, with Haitia moreleti sp.n.; Physini, with Laurentiphysa chippevarum g.n., sp.n., Physa mirollii nom.nou.; and Physellini, with Chiapaphysa g.n., and C. grijalvae, C. pacifica spp.nn., Utahphysa g.n., Archiphysa g.n., with A. ashmuni, A. sonomae spp.nn., Physella hemphilli sp.n., and Ultraphysella sinaloae g.n., sp.n. The simplest reproductive system is found in Austrinauta of the Aplexinae; its penial complex approaches that in the related family Lymnaeidae. Within Physinae a close approximation is found in Haitia. By these two genera the two subfamilies are drawn close together. Four grades of progressive complexity are recognized: (I) penial sheath entirely muscular; (II) penial sheath with both glandular and muscular tissue; (III) penis with penial stylet or other specialization of the tip of the penis; and (IV) pore of penial canal lateral rather than terminal as in the lower grades. In both subfamilies there are clades with glandular tissue in the penial sheath, a penial sheath subdivided into two parts, and tip of penis specialized in various ways. These clades are formalized as new tribes. Of 23 genera of Physidae, 17 occur in Pacific drainages of North and Central America, eight of these restricted to the region. Concentration of primitive genera along the Pacific coast from Mexico to Costa Rica conforms to previous observations that primitive pulmonate families are concentrated within, or along the continental margins of, the Pacific Ocean. An ancestral origin of Physidae along an ancient eastern Pacific coast is probable. From this region the several lineages have spread north, south and east in the Americas, and through Siberia to Europe. Although Physinae have fewer genera than Aplexinae (11 v. 12), they have more species (47 v. 34). Greater land area in the temperate zone has provided more opportunity for speciation of Physinae, in contrast to the generally tropical and warm-temperate range of Aplexinae. Furthermore, 10 species of Physinae are localized in individual lakes, whereas Aplexinae are not lake-dwellers. Both well-developed egg strings and capsular strings are found in the spawn of Sibirenauta elongatus. These structures have been known in Lymnaeidae, but not hitherto in Physidae; they are a link with some marine groups, such as Siphonariidae. Spiral color bands and white streaks in the shell of Mexinauta recall those in Lancidae (Lymnaeacea), whereas the radula of Physidae is like that of Chilinidae. Physidae thus show affinities to various basal stocks of aquatic pulmonates; no clear-cut sister-group can be recognized. Most species have a restricted range; out of 55 with sufficiently detailed information for analysis, 25 are limited to a single 1 degrees x 1 degrees quadrangle. Only a few species are widespread, on one or even two continents. Accordingly, more species of Physidae are threatened by habitat destruction than in other families of Hygrophila with generally wider distributions. Other features are a key to genera; catalog of more than 430 names applied to living Physidae, with original reference, type locality, and location of type specimens; summary of museums with types; and glossary.     

Plesiophysa dolichomastix sp. n. (Gastropoda: Planorbidae)

A new species of planorbid mollusc, Plesiophysa dolichomastix (Greek dolichos = long, mastix = flagellum), collected from Lagoa da Pedra, municipality of Santa Rosa, state of Goiás, Brazil (15 degrees 01'S, 47 degrees 13'W) is described. It is indistinguishable by the shell characters from the five congeneric species described so far: P. striata (Orbigny, 1841), P. granulata ("Shuttleworth" Sowerby, 1873), P. guadeloupensis ("Fischer" Mazé, 1883), P. ornata (Haas, 1938) and P. hubendicki Richards & Ferguson, 1962. It differs from the anatomically studied species in the following characters: about 50 ovotestis diverticula, against 12 in granulata, 100 in ornata, unstated in hubendicki; and length of flagella - about as long as the penial complex -, against about 1/3 to 1/6 in the other three.     

Two new species of Temnocephala (Platyhelminthes, Temnocephalida) from the South American snake-necked turtle Hydromedusa tectifera (Testudines, Chelidae)

Temnocephala brevicornis Monticelli, 1889 is the only species of the genus Temnocephala Blanchard, 1849 reported from chelonians to date. During a survey of the species of Temnocephala extant in southern Uruguay, two new species were found on the chelonian Hydromedusa tectifera Cope, 1869. They are described here as Temnocephala pereirai n. sp. and Temnocephala cuocoloi n. sp. Both resemble T. brevicornis, but differ in the morphometry of the penial stylet, and in qualitative details of the reproductive complex. Temnocephala pereirai n. sp. differs from T. brevicornis by having a massive, cylindrical sphincter in the distal portion of the vagina, and a seminal vesicle that opens into the subpolar to equatorial portion of the contractile vesicle. In addition, the penial stylet in Temnocephala pereirai n. sp. is large in relation to body size, straight and more slender, having the distal portion of its shaft slightly sinuous, and a smaller introvert equipped with about 16 distal crowns of smaller spines. Temnocephala cuocoloi n. sp. is most similar to T. brevicornis, but differs by having a smaller, curved penial stylet that has a smaller introvert in relation to stylet size, with about 10 distal crowns of smaller spines. A key to the species of the Temnocephala from chelonians is provided. This study supports the validity of the following characters previously proposed for the taxonomy of the genus Temnocephala: the shape of the sphincters in the female reproductive system, the shape of the penial stylet, and the number, size, and position of spines in the introvert.     

TWO NEW SPECIES OF THE GENUS ISLAMIA RADOMAN, 1973 FROM ITALIAN ISLANDS (PROSOBRANCHIA, HYDROBIIDAE)

Two new Italian species of the genus Islamia (Prosobranchia:Hydrobiidae), one living in eastern Sicily (I. cianensis), andone on Elba Island (Tuscan Archipelago, Italy) (I. gaiteri)are described. The two species are distinguished on the basisof shell and anatomical characters, mainly those of the malegenitalia. I. cianesis n. sp. is characterized by a valvatoidshell and a penial lobe with internal band of glandular tissuenot distinct in its lower portion from the penis body but bulgingapically as a small knob. I. gaiteri n. sp. is characterizedby a planispiral shell and a small lateral penial lobe withoutinternal glandular tissue. (Received 20 December 1993; accepted 27 June 1994)     

Functional morphology of the mammiliform penial glands ofLittorina saxatilis (Gastropoda)

Summary The functional morphology of the mammiliform penial glands ofLittorina saxatilis has been investigated with both light and electron microscopy. These penial glands line the ventral edge of the penis and orient with the female mantle during copulation. Secretions are released from the penial glands to this interface where they probably function in adhesion. The penial gland secretions comprise heterogeneous granules as well as apocrine and mucous secretions. The heterogeneous granules are produced in separate multicellular glands arranged in a series of lobes that lie outside a thick smooth muscle layer enclosing the lumen. Each glandular lobe is surrounded by a thin layer of smooth muscle. Secretions are transported in individual cellular processes that pass through the thick smooth muscle layer and empty into the lumen. Surrounding the lumen is an epithelium containing apocrine secretory cells as well as occasional goblet-type, mucous cells. The combined action of the muscles forces secretions out of the lumen through the penial papilla, onto the external surface of the mammiliform penial gland. Longitudinal muscles extend into the penial papilla enabling its protrusion or retraction. Retraction of the penial papilla following secretion release is thought to create negative pressure beneath the penial gland producing suction adhesion. The visco-elastic properties of the penial gland secretion are qualitatively different from foot mucus and may represent specialization to an adhesive function.     

Stylet formation in Anisus vortex (Linnaeus, 1758) (Gastropoda: Planorbidae)

Soldatenko, E.V., Shatrov A.B. and Shumeev, A.N. (2010). Stylet formation in Anisus vortex (Linnaeus, 1758) (Gastropoda: Planorbidae). —Acta Zoologica (Stockholm) 92 : 377–382. The detailed stylet morphology and stylet formation during postembryonic development in the pulmonate mollusk Anisus vortex (Linnaeus, 1758) are described using scanning electron microscopy (SEM) and histological methods. The stylet begins to develop in the lumen of the copulatory apparatus and then assumes its final position inside the penial sac. The developing stylet lying between two epithelial layers is undergoing chitinization mediated by secretion of the secretory epithelium of the penial sac that completes on the 80–120th day after hatching of mollusks from the egg masses. The stability of the characters of stylet morphology and their significance for the systematics of Planorbidae are discussed.     

Cell size and dorsal cilia: are they useful features for the identification of Stylonychia mytilus (Ciliophora, Spirotrichea) and its subpopulations?

It was investigated whether (1) the number of cilia of the dorsal kineties 3 and 4 and (2) the cell length are species-specific characters which can be used to distinguish the sibling species S. mytilus and S. lemnae. The number of cilia of the dorsal kineties 3 and 4 is a relatively constant, reliable species-specific character in all investigated strains of both species and rather independent from the origin and the nutritional condition of the cells. The cell length is also a reliable species character, if strains of both species from Germany are compared (under identical nutritional conditions). However, all S. mytilus strains from China, Australia and Peru are significantly smaller forming one (or some) "small" subpopulations or subspecies, compared with a "big" subpopulation from Germany. The small ones cannot always be distinguished by size alone from S. lemnae cells. Thus the cell size in S. mytilus is not in all geographic regions a species character, but can be used to characterize subspecies.     

Modification of the structure of penial glands in males of the intertidal molluscs Littorina saxatilis and L. obtusata under the influence of the infestation by trematode parthenites

Sporocycts of the "pygmaeus" microphallides (Microphallus piriformes) are localized in hepatopancreas and gonads of Littorina molluscs causing total parasitic castration. A histological study of penial glands in Littorina saxatilis and L. obtusata males infested with trematodes M. piriformes has been made. Copulatory organs of noninfested molluscs, molluscs after recent contamination (with not completely formed daughter sporocysts), and molluscs containing mature metacercariae inside daughter sporocysts were examined. Based on the data obtained, probable dynamics of the histological structure of infested glandular apparatus was established. It was shown, that the trematode infestation have an influence on the muscular and secretory parts of penial glands. The wall of the penial gland muscular capsule becomes more fine in infested L. saxatilis. On the contrary, this wall is vastly thicker in infested L. obtusata, as compared with noninfested individuals. Glandular cells of the molluscs' penial glands decreases the amount of granular secret in both species. In L. obtusata the number of secretory cells is shown to be reduced up to their total disappearance. The above pathological changes probably prevent normal function of penial glands.     

Musculature of the penial complex: A new criterion in unravelling the phylogeny of Hygrophila (Gastropoda: Pulmonata)

The taxonomy of freshwater pulmonates (Hygrophila) has been in a fluid state warranting the search for new morphological criteria that may show congruence with molecular phylogenetic data. We examined the muscle arrangement in the penial complex (penis and penis sheath) of most major groups of freshwater pulmonates to explore to which extent the copulatory musculature can serve as a source of phylogenetic information for Hygrophila. The penises of Acroloxus lacustris (Acroloxidae), Radix auricularia (Lymnaeidae), and Physella acuta (Physidae) posses inner and outer layers of circular muscles and an intermediate layer of longitudinal muscles. The inner and outer muscle layers in the penis of Biomphalaria glabrata consist of circular muscles, but this species has two intermediate longitudinal layers separated by a lacunar space, which is crossed by radial and transverse fibers. The muscular wall of the penis of Planorbella duryi is composed of transverse and longitudinal fibers, with circular muscles as the outer layer. In Planorbidae, the penial musculature consists of inner and outer layers of longitudinal muscles and an intermediate layer of radial muscles. The penis sheath shows more variation in muscle patterns: its muscular wall has two layers in A. lacustris, P. acuta, and P. duryi, three layers in R. auricularia and Planorbinae and four layers in B. glabrata. To trace the evolution of the penial musculature, we mapped the muscle characters on a molecular phylogeny constructed from the concatenated 18S and mtCOI data set. The most convincing synapomorphies were found for Planorbinae (inner and outer penis layers of longitudinal muscles, three-layered wall of the penis sheath). A larger clade coinciding with Planorbidae is defined by the presence of radial muscles and two longitudinal layers in the penis. The comparative analysis of the penial musculature appears to be a promising tool in unraveling the phylogeny of Hygrophila.     

Observations on the sex characters of the timber-boring sphaeromids (Isopoda) of the Indian waters

The timber-boring isopods (family Sphaeromidae) namely Sphaeroma terebrans, S. annandalei, S.a. travancorensis and S. triste occurring in Indian waters were studied for primary and secondary sex characters. A concise comparative account of the primary and secondary sex characters such as penial sacs, appendix masculina and oostegites has been given. The sexual dimorphism exhibited by the seventh pair of peraeopods of S. terebrans is explained fully. The sexual disparity in the body length of two species of Sphaeroma has also been described.     

Taxonomic revision of the Pyrgulopsis gilae (Caenogastropoda,Hydrobiidae) species complex,with descriptions of two new species from the Gila River basin,New Mexico

We describe two new species of springsnails (genus Pyrgulopsis) for populations from the middle Fork and upper East Fork of the Gila River Basin (New Mexico) that had been previously identified as P. gilae. We also restrict P. gilae to its originally circumscribed geographic range which consists of a short reach of the East Fork Gila River and a single spring along the Gila River (below the East Fork confluence). These three species form genetically distinct lineages that differ from each other by 3.9–6.3% for mtCOI and 3.7–8.7% for mtNDI (the latter data were newly obtained for this study), and are diagnosable by shell and penial characters. Collectively the three species form a strongly supported clade that is distinguished from other congeners by the unique presence of two glandular strips on the dorsal surface of the penial filament. These findings suggest that the conservation status of P. gilae, which was recently removed from the list of candidates for listing as endangered or threatened by the United States Fish and Wildlife Service, should be revisited and that the two new species may also merit protective measures given their narrow geographic ranges.     

Bamboo germplasm screening with nuclear restriction fragment length polymorphisms

Summary Bamboo species are difficult to identify because flowering material is seldom available and taxonomy is of necessity based on vegetative characters. To evaluate the utility of restriction fragment length polymorphism (RFLP) analysis in bamboo systematics and germplasm screening, a library of random genomic probes from a Phyllostachys nigra PstI library was constructed. Probes from the library were used to screen bamboo germplasm consisting mostly of temperate bamboos of the genus Phyllostachys. RFLP variation was abundant, and species-specific patterns were readily obtained. Chloroplast DNA showed little variation among the bamboo accessions analyzed.     

New insights into the functional morphology of the male copulatory apparatus of bullid gastropods

In this study, semi-thin sections stained with histochemical techniques and transmission electron microscopy were used to obtain new data about the morphology and function of the male copulatory apparatus of the cephalaspidean gastropod Bulla striata. The apparatus comprises a vestibule, a penial papilla and a prostate consisting of a coiled unbranched tube ending in a blind caecum. The penial papilla and the coiled tubular prostate are enclosed by a muscular sheath, which is continuous with the muscular tissue of the vestibule. The epithelium lining the lumen of the vestibule is formed by ciliated and mucus-secreting cells. Two new types of subepithelial secretory cells were discovered in this region. The penial papilla is a muscular structure without secretory cells in the epithelium lining the narrow lumen. The tubule that constitutes the prostate possesses a muscular wall and can be divided in three distinct regions: a non-secretory duct connected to the penial papilla, a glandular region rich in large secretory cells and the terminal caecum containing just a few small secretory cells. In the terminal blind caecum, the muscular sheath is fused with the muscular wall of the tubular prostate. Large numbers of spermatozoa were found in the glandular region and in the terminal caecum of the prostate. A new functional mechanism is proposed to explain penial eversion during copulation. This differs from a previous hypothesis in two main aspects: (1) existence of a permanent penial papilla in mature animals acting as a functional penis and (2) functional role of vestibule during copulation, which everts and surrounds the penial papilla, while the latter protrudes outwards.     

Morphometric and molecular identification of the female castes of Bombus ignitus and B. ardens (Apidae: Hymenoptera)

Among Korean bumblebees, Bombus ignitus and B. ardens are relatively abundant and important for pollination of wildflowers and agricultural crops. Although the males are easily distinguishable phenotypically, the female castes are difficult to identify from each other. Here we evaluated the value of some morphometric characters in species identification. Also, we developed a polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) to discriminate these similar species. In spite of statistically significant differences of some morphological characters between two species, overlapping quantitative traits hindered accurate identification of the species. However, using 435 bp of COI gene and AluI, BspHI and Earl restriction enzymes allowed molecular identifications of these two species with unique profiles from the digestion by these restriction enzymes. This method can also be applied for older specimens with some morphological characters damaged. We also developed species-specific primers for fast and cost-effective identification of these species.     

The comparative anatomy and systematics of Jamaican Urocoptidae (Mollusca: Pulmonata)

Jamaican Urocoptidae can be assigned to three subfamilies, the Urocoptinae Pilsbry 1902, Apominae Paul 1982 and Microceraminae Pilsbry 1902, on shell and anatomical characters. Urocoptinae are characterized by a cylindrical or conical decollate shell; genitalia with an elongate spermatheca and no penial retractor muscle; the left ocular retractor arising from the pharyngeal retractor and both oculars divided anteriorly; a short or long radula (L/W ≏ 5 or ≏ 10) with V-shaped rows of teeth, no marginals and the mesocones and ectocones of laterals widely separated in alternating rows; and include the genera Urocoptis Beck, Anoma Albers and Spirostemma Pilsbry & Vanatta. The Apominae are characterized by elongate-cylindrical decollate shells; genitalia with a globular spermatheca and a penial retractor muscle; both ocular retractors arising from the pharyngeal and both divided anteriorly; an extremely long radula (L/W= 25–45) with narrow, weakly-lobed centrals flanked by two enormous laterals with ectocones reduced or absent, and 4–9 marginals; and include the genera Apoma Beck, Mychostoma Albers, Geoscala Pilsbry & Vanatta and Simplicervix Pilsbry. The type species of the type genera of both subfamilies occur in Jamaica and their anatomy is described. Jamaican Microceraminae include one species, Microceramus gossei (Pfeiffer) which has a conical, entire shell; genitalia with an oval spermatheca and no penial retractor muscle; neither ocular retractor arising from the pharyngeal and neither branched anteriorly; a short radula (L/W ≏ 5) with straight rows of lateral teeth and no marginals. Cladistic analysis suggests that Microceramus is the most primitive genus; that within the Urocoptinae Anoma and Spirostemma are more closely related to each other than either is to Urocoptis ; and that within the Apominae, Apoma is less closely related to Mychostoma, Geoscala and Simplicervix than they are to each other.     

The early life history of two sympatric New Zealand octopuses: eggs and paralarvae of Octopus huttoni and Pinnoctopus cordiformis

This study combined morphological and morphometric information on egg clutches, egg capsules and paralarvae of two sympatric coastal octopuses from New Zealand waters, Octopus huttoni and Pinnoctopus cordiformis, to provide species-specific traits to identify their early life stages obtained from field surveys. Eggs of O. huttoni (2.5 mm length; 1 mm width) were entwined with one another forming strings that ranged from 11 to 25.8 mm in length. Eggs of P. cordiformis (6.4 mm length; 1.5 mm width) were significantly bigger than those of O. huttoni and were grouped in small clusters of about seven eggs. Paralarvae O. huttoni and P. cordiformis differed in hatching size (1.4 mm versus 3.1 mm mantle length), number of suckers per arm (four versus eight), number of lamellae per outer demibranch (five versus ten) and arrangements of chromatophores in the body surface (29 to 59 versus 91 to 179), respectively. The morphological traits described in hatchlings from the laboratory allowed comparisons with field-collected paralarvae, suggesting that such characters were reliable species-specific patterns to enable a consistent differentiation between the early life stages of these two sympatric species, even in the absence of the brooding female.     

Functional anatomy of male copulatory organs of Pomacea canaliculata (Caenogastropoda, Ampullariidae)

This study was aimed to investigate the functional morphology of copulation and sperm transfer in the invasive snail Pomacea canaliculata. Three-dimensional renderings of the male copulatory apparatus were made and showed elaborate systems for innervation and for hemolymph supply and drainage. A key component of the male copulatory apparatus is the penial sheath, which shows three specialized glands; the medial and distal glands may participate in adherence to the mantle cavity wall of the female during copulation. The outer gland has an epithelium composed of columnar cells with branched microvilli, mucous goblet cells and large granular secretory cells containing intragranular crystalloids, which produce an exocrine secretion during copulation. The interaction of male/female copulatory organs was studied in dissections of snap-frozen pairs. Sperm are left in the sperm pit, at the end of the pallial spermiduct. Afterwards, the muscular action of the penial bulb takes the sperm up to the vermiform penis, which slides from the penial pouch into the central groove of the penial sheath, and it later emerges through a T-shaped sulcus of this structure and enters the female vagina. Then, it climbs through the capsule duct, and its tip reaches the proximity of the seminal receptacle. A model of copulation and sperm transfer is presented on the basis of the new findings and on published literature.