Gastropods are among the most diverse animal clades, and have successfully colonized special habitats such as marine sand interstitial. Specialized meiofaunal snails slugs tiny worm-shaped. They combine regressive features – argued to be due progenetic tendencies with convergent adaptations. Microscopic size concerted convergences make morphological examination non-trivial hamper phylogenetic reconstructions. The enigmatic turbellarian-like Rhodopemorpha a small group that has puzzled...

Abstract Euthyneuran gastropods represent one of the most diverse lineages in Mollusca (with over 30,000 species), play significant ecological roles aquatic and terrestrial environments affect many aspects human life. However, our understanding their evolutionary relationships remains incomplete due to missing data for key phylogenetic lineages. The present study integrates such a neglected, ancient snail family Ringiculidae into molecular systematics Euthyneura first time is supplemented by...

Heterobranchia is a diverse clade of marine, freshwater, and terrestrial gastropod molluscs. It includes such disparate taxa as nudibranchs, sea hares, bubble snails, pulmonate land snails slugs, number (mostly small-bodied) poorly known slugs collectively referred to the "lower heterobranchs". Evolutionary relationships within have been challenging resolve group has subject frequent significant taxonomic revision. Mitochondrial (mt) genomes can be useful molecular marker for phylogenetics...

Nudibranch molluscs of the genus Corambe differ from most other Doridoidea by having ventral rather than dorsal anus and gills. Because these features, such as separate cerebral pleural ganglia, corambids have been considered an archaic or enigmatic group. The first tropical eastern Pacific species is described in morphological some histological detail. Selected organs circulatory central nervous features are reconstructed serial semithin slides visualized three dimensions using Amira...

Abstract The gastropod infraclass Euthyneura comprises at least 30,000 species of snails and slugs, including nudibranch sea hares garden snails, that flourish in various environments on earth. A unique morphological feature is the presence two pairs sensory head tentacles with different shapes functions: anterior labial posterior rhinophores or eyestalks. Here we combine molecular phylogenetic microanatomical evidence suggests have originated by splitting original single tentacle pair (with...

Forming a small group of mainly marine meiofaunal slugs, the Acochlidia have recently been separated from traditional opisthobranch gastropods and placed within mixed clade pulmonates, Sacoglossa Pyramidelloidea on basis molecular data. In light this new phylogenetic framework, we examined several populations comparatively giant Strubellia (Acochlidiidae s. l.) found in rivers Solomon Islands Vanuatu, combining microanatomical methods (interactive three-dimensional models are given online...

The turbellarian-like, radula-lacking Rhodope has been a mystery to taxonomists for over 160 years and was considered specialized off-shoot of either opisthobranch or pulmonate Euthyneura. Occasionally reported from intertidal waters sand habitats all continents, most species these minute slugs are poorly known characterized mainly by differences in pigmentation. To understand the evolution heterobranch microslugs, we established morphological dataset describing new found temperate southern...

Sediment-covered ocean floors constitute one of the largest and at same time least explored habitats on Earth, still hiding an unknown level species diversity. Coastal areas this marine mesopsammic habitat harbor a variety heterobranch snails slugs. These gastropods long were puzzling due to their unclear phylogenetic positions, aberrant morphologies lack knowledge regarding biology Herein, we briefly review advances interstitial gastropod exploration, emphasizing that molecular approaches...

Yasunori Kano1, Hiroaki Fukumori1,2, Bastian Brenzinger3 and Anders Waren4 Department of Marine Ecosystems Dynamics, Atmosphere Ocean Research Institute, The University Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan; Graduate School Frontier Sciences, 277-8561, Bavarian State Collection Zoology, Munchhausenstr. 21, D-81247 Munich, Germany; Swedish Museum Natural History, Box 50007, SE-10405 Stockholm, Sweden

Abstract The marine animal phylum Placozoa is characterized by a poorly explored cryptic biodiversity combined with very limited knowledge of their ecology. While placozoans are typically found as part the epibenthos coastal waters, known placozoan predators, namely small, shell‐less sea slugs belonging to family Rhodopidae (Mollusca: Gastropoda: Heterobranchia), inhabit interstitium seafloor sediment. In order gain further insights into this predator–prey relationship and expand our...

This study is the first to examine entire microanatomy of a representative limnic family Acochlidiidae s.l., belonging otherwise marine mesopsammic Acochlidia. A paratype Strubellia paradoxa (Strubell, Citation1892) was reconstructed three-dimensionally from serial semi-thin sections using software Amira; additional material recently collected close type locality on Ambon Island, Indonesia examined by scanning electron microscopy. Results are critically compared with original description...

Rhodopemorphs are small, interstitial or psammobiotic heterobranch slugs, which have been troubling to place phylogenetically. Their small size and habit of living in among sediment led a correlated reduction simplification morphology, consequently contradictory phylogenetic signal from anatomical features. When morphological data previously used generate hypotheses, these were vulnerable the effects homoplasy. We collected multiple species Rhodope, along with another rhodopemorph genus...

The Murchisonellidae are a small taxon of minute snails with high-spired shell that occur in shallow marine habitats. Molecular phylogenetics recently revealed they not members the externally similar yet phylogenetically derived Pyramidellidae, but instead potentially one oldest clades among heterobranch Gastropoda. Furthermore, current data surprisingly indicate sister-group relationship Rhodopemorpha, highly aberrant slugs previously unclear affinities. characterized by specialized...

The Thecosomata are pelagic euopisthobranch pteropods that important for marine food chains, but threatened by ocean acidification. Members of the suborder Euthecosomata either torted snails with a coiled, sinistral shell (Limacinidae) or straight-shelled symmetrical body and an unusual ventral mantle cavity (Orthoconcha). classification taxonomy euthecosomes still depends on shells, is being challenged initial molecular data. There large morphoanatomical information dating from beginning...

The evolution and diversification of euthyneuran slugs snails was likely strongly influenced by habitat transitions from marine to terrestrial limnic systems. Well-supported phylogenies with detailed morphological data can provide information on the historical, biological ecological background in which these shifts took place allowing for comparison across taxa. Acochlidian are "basal pulmonates" uncertain relationships other major panpulmonate clades. They present a unique evolutionary...

The genus Micromelo (family Aplustridae) occurs in almost all tropical and subtropical waters across the globe, with exception of Eastern Pacific. Most authors consider undatus (Bruguière, 1792) as only valid species this genus. This study examines populations specimens identified M. its geographic range, using morphological genetic data from two mitochondrial genes (16S CO1) one nuclear gene (Histone H3). results reveal that is a complex four consistent anatomical differences. A literature...

The freshwater slugs of the genus Acochlidium (Heterobranchia, Gastropoda, and Acochlidimorpha) are peculiar, one to two centimeter sized animals found only in small coastal rivers streams Southeast Asian Western Pacific islands. When first described by Bücking, author observed a branching "net dendritic vessels connected heart," which he assumed have replaced original gastropod gill. In present study, we compare renopericardial systems four species microanatomical, histological...

Abstract The systematics of side-gilled slugs face long-lasting incongruencies provided by morphological and molecular data. Parsimonious assessments divided the single superfamily Pleurobranchoidea into shell-less Pleurobranchaeidae internally shelled Pleurobranchidae, including aberrant helicoid-shelled Tomthompsonia. Molecular evidence has proven untrustworthy to date, revealing contrasting hypotheses. This study’s multilocus phylogeny benefits from a dense taxon sampling 94...

Abstract Gastropods (slugs and snails) are prominent species-rich faunal elements in marine terrestrial habitats of the tropics. While several clades snails inhabit freshwater systems, slugs extremely rare freshwater: only centimeter-sized Acochlidiidae, with currently three genera, contain more than one species live lower reaches island streams an area comprising Eastern Indonesia, Fiji, Palau. Where known, this unique group specialized predators other amphidromous snails’ egg capsules...