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The annelid clade Amphinomidae, commonly known as "fireworms," is notorious for causing skin inflammations after physical contact. These injuries are caused by the chaetae of the animals, which are calcified and particularly brittle. The incorporation of calcium carbonate particles and their disintegration cause the chitinous lamellae within a chaeta to break apart and result in a prominent inner cavity. Although the chaetae of Amphinomidae are well studied, data concerning their sister group, Euphrosinidae, are scarce. In this study, we examined the chaetae of two species of Euphrosine for the first time regarding the variety of chaetal types, their ultrastructure, elemental composition, and arrangement. This allows us to get a better understanding of chaetal characteristics in the ground pattern of Amphinomida. We were able to determine bifurcate chaetae as the primary chaetal type in Amphinomida and provide evidence that their aciculae must have evolved secondarily. Calcification is a common feature among amphinomidan chaetae and regarded as autapomorphy of Amphinomida. Finally, a single dorsal formative site in each notopodium and neuropodium, found in Euphrosine foliosa, likely represents the ancestral state in Amphinomida. There is no evidence for venom production or secretory cells associated with the chaetae of Euphrosine, which is in accordance with what was previously observed in Amphinomidae. Our study also complements further studies into chaetal characteristics such as the number and arrangement of formative sites. [ABSTRACT FROM AUTHOR]

The palaemonid genus Sandyella includes S. tricornuta (Isla María Madre, Mexico), S. mclaughlinae, S. bicornuta, S. quadricornuta and S. sexicornuta (Clipperton Island, France). These species were first described in the genus Chacella based on collections of few individuals and limited to no ecological information. Sandyella was later erected to differentiate Chacella kerstitchi from Chacella tricornuta and Chacella mclaughlinae. The remaining three Chacella species (<3 mm cephalothorax length) were later also moved to Sandyella and distinguished mainly based on variation in the less than three protuberances on the cephalothorax and number of protuberances on the abdomen. Since their description from their type localities, only Sandyella tricornuta has been additionally recorded from Bahía de La Paz, Mexico. Collections done at 13 locations along the Gulf of California (2009–2010) yielded 2,905 specimens including representatives of all Sandyella species as epibionts of 57 black coral colonies Antipathes galapagensis, which prompted a closer taxonomic examination. Based on observations of live and preserved specimens, including type material, population cephalothorax size frequency and mitochondrial COI data, we inferred that all current Sandyella species (a) exhibit three protuberances on the cephalothorax; (b) cephalothorax length and number of protuberances appear to be progressive among species; (c) species exhibit high COI sequence similarity; and d) the five Sandyella species were observed cohabiting the same black coral colony. Therefore, we conclude that the five current Sandyella species are in fact distinct ontogenetic stages of a single species, S. tricornuta, and our results of a morphological Bayesian analysis led us conclude that this species belongs to the genus Sandyella rather than Chacella. [ABSTRACT FROM AUTHOR]

Abstract: Aphroditiformia represents one of the most successful radiations of annelids, and is therefore an interesting model to understand morphological and functional evolution. Previous phylogenetic analyses yielded most families as monophyletic but excluded anchialine and interstitial species while failing to recover relationships within Sigalionidae. Here we address these shortcomings through the analysis of four molecular markers and 87 morphological characters sampled across 127 species under the assumptions of parsimony and model‐based methods. Of the 34 newly sequenced taxa, five anchialine and 24 interstitial species were included, with increased representation of Sigalionidae. An additional 28 elusive Sigalionidae taxa were included, represented only by morphological partitions. Molecular and morphological partitions were evaluated under exhaustive sensitivity analyses, testing the effects of alignment algorithms and optimization criteria on tree topologies. Our trees congruently recovered six clades corresponding to the families within Aphroditiformia: Acoetidae, Aphroditidae, Eulepethidae, Iphionidae, Polynoidae and Sigalionidae, respectively. An anchialine polynoid lineage was nested among strictly deep sea species, and interstitial pisionids and pholoids formed two independent clades nested within Sigalionidae. Additionally, Sigalionidae resulted in four clades, defined by combinations of apomorphies, and hereby we propose the subfamilies Pelogeniinae, Pholoinae, Pisioninae, Sthenelanellinae, as well as the provisionally included polyphyletic Sigalioninae. [ABSTRACT FROM AUTHOR]

Two-jawed (duognathous) terrestrial leeches in the Haemadipsidae are major pests across their wide geographic range, represented by numerous endemic species in Australia and across many islands in the Indian and Pacific Oceans. However, haemadipsid taxonomy, based largely on externally visible characters, remains in conflict with phylogenetic relationships. We capitalize on the power of microcomputed tomography ( μ CT), allowing for the first description of an extant soft-bodied species - Chtonobdella tanae sp. n. - using this technology. Several fixation strategies for soft-bodied invertebrates in μ CT scanning applications are also evaluated. Expanding on prior work, higher taxonomy of duognathous haemadipsids also was evaluated with phylogenetic analyses of DNA sequence data. Whereas monophyly of duognathous leeches was supported, substantial conflict remained with respect to named genera. Consequently, the genus Chtonobdella was revised to include all duognathous leech species previously distributed in 31, mostly monotypic genera. [ABSTRACT FROM AUTHOR]

This study revises the taxonomic status of the formerly monotypic Archinomidae, which is nested within paraphyletic Amphinomidae according to recent phylogenetic work. We focused our taxonomic sampling to evaluate the affinities of Notopygos and genera classified as 'fusiform' in body shape, including Archinome and Chloeia. Prior to this study, the phylogenetic placement of Notopygos had not been evaluated. We inferred the phylogenetic relationships of Notopygos within Amphinomidae based on nuclear and mitochondrial markers, and cytochrome c oxidase subunit I genetic divergences of five Notopygos species, including the newly described Notopygos kekooa sp. n. from the Gulf of California. The phylogenetic and morphological evidence, now including Notopygos species, justified the establishment of two subfamilies within Amphinomidae. In accordance with ICZN Article 36 (Principle of Coordination), both subfamilies are presented as status novus in the nomenclature ranks. [ABSTRACT FROM AUTHOR]

Rorqual whales (Family: Balaenopteridae) are the world's largest predators and sometimes feed near or at the sea surface on small schooling prey. Most rorquals capture prey using a behavioral process known as lunge-feeding that, when occurring at the surface, often exposes the mouth and head above the water. New technology has recently improved historical misconceptions about the natural variation in rorqual lunge-feeding behavior yet missing from the literature is a dedicated study of the identification, use, and evolution of these behaviors when used to capture prey at the surface. Here we present results from a long-term investigation of three rorqual whale species (minke whale, Balaenoptera acutorostrata; fin whale, B. physalus; and blue whale, B. musculus) that helped us develop a standardized classification system of surface lunge-feeding ( SLF) behaviors. We then tested for differences in frequency of these behaviors among the three species and across all rorqual species. Our results: (1) propose a unified classification system of six homologous SLF behaviors used by all living rorqual whale species; (2) demonstrate statistically significant differences in the frequency of each behavior by minke, fin, and blue whales; and (3) provide new information regarding the evolution of lunge-feeding behaviors among rorqual whales. [ABSTRACT FROM AUTHOR]

Over the last few decades, advances in molecular techniques have led to the detection of strong geographic population structure and cryptic speciation in many benthic marine taxa, even those with long-lived pelagic larval stages. Polychaete annelids, in particular, generally show a high degree of population divergence, especially in mitochondrial genes. Rarely have molecular studies confirmed the presence of 'cosmopolitan' species. The amphinomid polychaete Hermodice carunculata was long considered the sole species within its genus, with a reported distribution throughout the Atlantic and adjacent basins. However, recent studies have indicated morphological differences, primarily in the number of branchial filaments, between the East and West Atlantic populations; these differences were invoked to re-instate Hermodice nigrolineata, formerly considered a junior synonym of H. carunculata. We utilized sequence data from two mitochondrial (cytochrome c oxidase subunit I, 16S r DNA) markers and one nuclear (internal transcribed spacer) marker to examine the genetic diversity of Hermodice throughout its distribution range in the Atlantic Ocean, including the Mediterranean Sea, the Caribbean Sea, the Gulf of Mexico and the Gulf of Guinea. Our analyses revealed generally low genetic divergences among collecting localities and between the East and West Atlantic, although phylogenetic trees based on mitochondrial data indicate the presence of a private lineage in the Mediterranean Sea. A re-evaluation of the number of branchial filaments confirmed differences between East and West Atlantic populations; however, the differences were not diagnostic and did not reflect the observed genetic population structure. Rather, we suspect that the number of branchial filaments is a function of oxygen saturation in the environment. Our results do not support the distinction between H. carunculata in the West Atlantic and H. nigrolineata in the East Atlantic. Instead, they re-affirm the older notion that H. carunculata is a cohesive species with a broad distribution across the Atlantic Ocean. [ABSTRACT FROM AUTHOR]

Borda, E., Kudenov, J.D., Bienhold, C. & Rouse, G.W. (2012). Towards a revised Amphinomidae (Annelida, Amphinomida): description and affinities of a new genus and species from the Nile Deep-sea Fan, Mediterranean Sea. - Zoologica Scripta, 41, 307-325. The discovery of a new amphinomid species from wood falls deployed near cold seeps (1694 m) at the Nile Deep-sea Fan (Mediterranean Sea) highlights the need to revise Amphinomidae to better characterize amphinomid diversity. The phylogenetic affinities of the new amphinomid and 12 other species from nine Amphinomida genera were inferred using data from two nuclear (18S rDNA and 28S rDNA) and two mitochondrial (COI and 16S rDNA) genes. The phylogenetic analyses indicated a close relationship of the new species with other amphinomids associated with temporary pelagic substrata, including Amphinome sensu stricto (emended herein) and Hipponoa. The new species belongs to a distinct lineage and we, here, erect a new genus to accommodate it. Cryptonome gen. n. is the second amphinomid genus established for species from chemosynthetic environments. Cryptonome conclava sp. n. is distinguished morphologically from all previously described rectilinear Amphinomidae by lacking notochaetal hooks, having a reduced caruncle, modified neurochaetae and branchiae on nearly all segments. Taxonomic issues regarding amphinomid species presently assigned to Amphinome and the erroneous placement of related xylophylic taxa in Eurythoe are also outlined. We emend and restrict the five known oceanic flotsam species with stalked heart-shaped caruncles to Amphinome sensu stricto. An additional 15 species previously assigned to Amphinome may belong to other genera (e.g. Linopherus) and are here tentatively considered incertae sedis. Finally, Eurythoe turcica and Eurythoe parvecarunculata are transferred to Cryptonome gen. n. as new combinations. A revised key to a subset of rectilinear amphinomid genera (relevant to this study) is presented. [ABSTRACT FROM AUTHOR]

The relationships, as well as identification of species, within Helobdella (Glossiphoniidae) were explored through phylogenetic analysis and through an overview of the historical systematics of the genus. The phylogeny was determined using morphological data and the mitochondrial gene sequences of cytochrome c oxidase subunit I and nicotinamide adenine dinucleotide dehydrogenase subunit I. A broad representation of 15 ingroup species was sampled, including 10 individuals from South America. Outgroup taxa included five species of Haementeria . Cladistic analysis of all available data resulted in one most parsimonious tree. Results shed light on genetic divergence of members classified as the same species, including those that are not monophyletic. Historically, external morphological characters have played a significant role in contributing to the confusion in the classification of H. triserialis, H. papillata, H. lineata and H. fusca in North America. Re-evaluation of Verril's Clepsine papillifera var. b and var. d in a phylogenetic context provides a solution. Additionally, the genera Adaetobdella, Acritobdella, Dacnobdella and Gloiobdella created by Ringuelet are returned to Helobdella based on overlapping morphological characters. [ABSTRACT FROM AUTHOR]