Ventral Cirri Research Articles

A new species of Thoracophelia (Annelida, Opheliidae) from the Yellow Sea of South Korea.

Thoracophelia Ehlers, 1897 is a genus of Opheliidae characterised by the body divided into three distinct regions, modified parapodia in chaetiger 10 and a ventral groove restricted to the posterior half of the body. To date, 18 species have been described in the genus. Amongst them, six species have been recorded in northeast Asia. A new species, Thoracopheliafoliformis sp. nov., was discovered in the intertidal zone of the Yellow Sea, South Korea. This is the first Thoracophelia species report from the Yellow Sea. This new species is closely related to T.dillonensis (Hartman, 1938) from California and T.ezoensis Okuda, 1936 from Japan in having pectinate branchiae. However, the new species can be distinguished from the two species by the unique combination of the following characteristics: 15 pairs of wrinkled pectinate branchiae with 12-15 filaments at best development and a foliaceous mid-ventral plate in the pygidium instead of one or two thick ventral cirri. Detailed descriptions and illustrations of T.foliformis sp. nov. are provided. Sequences of the mitochondrial cytochrome c oxidase subunit I (COI), nuclear 18S ribosomal DNA (rDNA) and 28S rDNA of the new species were determined and analysed.

The function of the ATG8 in the cilia and cortical microtubule maintenance of Euplotes amieti.

Autophagy regulates the formation of primary cilia, which in turn affects autophagy. The relationship between autophagy and cilia is known to be bidirectional although the specific mechanisms involved have yet to be elucidated. In this study, we found for the first time that ATG8 protein localizes in the basal body of the dorsal kineties and the base of the ventral cirri in Euplotes amieti. ATG8 protein maintains the structural integrity of cilia and plays a role in the construction of the cortical ciliature and microtubule cytoskeleton associated with cilia. ATG8 gene interference leads to the degradation of IFT88, the transport protein in cilia, thus inhibiting the generation of cilia, and affecting the swing of cilia. This influences the swimming speed and cilia pattern, leading to death in Euplotes amieti.

New species of Glyphohesione and Pseudexogone (Annelida, Pilargidae) from the Gulf of Thailand

Two new species of Pilargidae, Glyphohesione pattaniensis sp. nov. and Pseudexogone losinensis sp. nov. are described from the southern Gulf of Thailand, Pattani Province. Glyphohesione pattaniensis sp. nov. is clearly distinguished from all other known species in the genus by having lateral antennae on the middle of the prostomium; lacking ventral cirri at chaetiger 2; first notopodial spines beginning at chaetiger 6; and having small epidermal papillae. Pseudexogone losinensis sp. nov. belongs to a group of species in the genus with eyespots present and differs from all other described species by the shape of the furcate chaetae with a strongly curved large tine and a tine with an open tip. An updated key to the species of Glyphohesione and Pseudexogone and a world map of both genera are also provided.

Ceciamaralia, a new genus of Dorvilleidae (Annelida) from deep waters of the Southwest Atlantic Ocean and an insight into its relationship within the family.

Dorvilleidae Chamberlin, 1919 is a family of Annelida containing some of the smallest 'polychaetes' species, being poorly studied worldwide, and with little knowledge regarding its diversity and occurrence. Samples obtained in oceanographic campaigns performed in the Southwest Atlantic Ocean (Brazilian coast) revealed a high number of specimens of dorvilleids, adding to our knowledge of the family's biodiversity. A detailed morphological analysis of these organisms has revealed a new genus, Ceciamaralia gen. nov., with two new species. The new genus differs from other Dorvilleidae genera in (i) the robust and enlarged pharynx which are frequently everted, (ii) unique composition of maxillae, with an elongated pair of serrated basal plates and one pair of anterior free maxillary plates with a long and thin anterior spine and (iii) ventral cirri present only in few first chaetigers. Ceciamaralia lanai gen. et sp. nov. is characterized by the presence of a broad and large dorsal cirrus on a few anterior parapodia and by furcate chaeta in supra-acicular fascicles. While Ceciamaralia nonatoi gen. et sp. nov. presents one geniculate chaeta instead of one furcate, the absence of dorsal cirri and, in some specimens, the absence of palps. A cladistic analysis supported the monophyly of Ceciamaralia gen. nov. by four synapomorphies related to the unique morphology of its maxillae, pharynx and appendages. This study is part of several recent taxonomic studies aiming to elucidate and increase the knowledge of Dorvilleidae, since it is part of a Ph.D project focused on the family.

A review of Eunicoidea (Annelida) from Falkland Islands waters including a new species of Hyalinoecia

Abstract Historic species records of the families Onuphidae and Eunicidae, from the Falkland Islands region, are reviewed and updated, new records added from intertidal and nearshore localities on and around the Falkland Islands, and a new species of Hyalinoecia described. Eight genera are reported from around the region including eight taxa of Onuphidae and two of Eunicidae, although most are only known from deep offshore waters. Kinbergonuphis dorsalis is re-described from type material, Kinbergonuphis sp. from the Falkland Islands is described and discrepancies between the two descriptions are examined. Hyalinoecia falklandica sp. nov. is described and the history of the genus and its misidentification in the region is discussed. The new species is distinguished from all other species in the genus through a combination of simple, unidentate falcigers on chaetigers 1 and 2, ventral cirri present to chaetigers 3 or 4, and branchiae present from chaetigers 26 or 27 to the end of the body. The historic record of Marphysa aenea from the Falkland Islands is also shown to be a misidentification and the actual, as-yet-undetermined species present is described. Problems surrounding a correct identification of Marphysa species, other species that do not quite fit current descriptions, and additional Eunicoidea taxa that might be expected to occur in the region are also discussed.

A closer look at the taxonomic and genetic diversity of endemic South African Marphysa Quatrefages, 1865.

The current study investigates the final unresolved cosmopolitan species of Marphysa in South Africa, Marphysa corallina, collected from KwaZulu Natal, Eastern and Western Cape provinces, together with another species collected from northern KwaZulu Natal. Morphological and genetic data prove that M. corallina, originally described from Hawaii, does not occur in South Africa. The curvature of the inner base on maxilla I, the elevated inner base of maxilla II, and the ventral cirrus as a transverse welt with a rounded tip allow us to identify it as a new species of Treadwellphysa, T. izinqa sp. nov. (common name: brown wonderworm). Characteristic traits include the basal reddish and distal golden colour of the subacicular hook, the ear-shaped postchaetal lobe, and tridentate falcigers which is reported for the first time for the genus. This species is harvested as bait on the south coast of SA, although less frequently than the more common blood wonderworm, Marphysa haemasona Quatrefages, 1866, and can be distinguished by its more uniform brown colouration and white-tipped antennae. A second species, Marphysa mzingazia sp. nov., is characterized by red eyes, six branchial filaments extending to the posterior end, the golden aciculae in posterior chaetigers, weakly bidentate yellow/brown subacicular hooks, and the presence of similar sized spinigers along the body. A molecular analysis based on cytochrome oxidase I fragments confirm both taxa as different species. A key for all South African species of Marphysa is included.

Two new species of Marphysa (Annelida, Eunicidae) from southern Australia.

Two new species of Marphysa Quatrefages, 1866 are described from the southeast coast of Australia. With the presence of only compound spinigers and the branchiae present over many chaetigers, Marphysa baudini n. sp. belongs to the Sanguinea-group. This species has ventral cirri with an inflated base and digitiform tip and thick and wide anodont pectinate chaetae, with 3-5 internal long and thick teeth. With the presence of only compound falcigers, Marphysa davidattenboroughi n. sp., belongs to the "Aenea-group". This species is characterised by the presence of a bilobed prostomium, a single pair of pygidial cirri and by the presence of thick, and wide anodont pectinate chaetae with 4-6 long internal and thick teeth.

Strongylidium koreanum n. sp. (Protozoa: Ciliophora), a new soil species from South Korea.

Strongylidium koreanum n. sp., a new soil ciliate from Jeju Island, South Korea, is described based on live observations, protargol impregnation, and molecular analysis of the 18S rRNA gene sequence. It is characterized by the following morphological features: cell outline more or less fusiform, posterior end broader than anterior end; grayish under low magnification; cortical granules absent; 23-32 adoral membranelles; three enlarged frontal cirri; buccal cirrus and postoral ventral cirrus present; 27-42 left and 15-28 right ventral cirri; 23-36 left and 30-46 right marginal cirri; three dorsal kineties; three caudal cirri; and two macronuclear nodules with two or three micronuclei. Phylogenetic analyses show that Strongylidium is monophyletic.

A new species of Pisione (Annelida, Sigalionidae) from Palk Bay, India

Abstract Pisione Grube, 1857 was considered rare animals, but its numbers have increased in recent decades. New species have been described, mainly from the Indo-Pacific region. In this study, we described Pisione balasubramaniani sp. nov., from Tamil Nadu, southeastern coast of India. The new species resembles other species in the ‘remota complex’ in the shape of the copulatory organs, elongated ventral cirri on the first segment and a short dorsal cirrus on the second segment. It can be distinguished from members of this group by having protruding notoacicula from the anteriormost to the very last chaetigers, three pairs of copulatory organs on chaetigers 15–17 and variances in the morphology of the copulatory organ. We also provide an updated comparison between all known species of Pisione based on key morphological characters. We also present a discussion of species of this genus in India and nearby regions.

Rhynchospioaciliata sp. nov., a new spionid species (Annelida, Spionidae) from the Korea Strait.

A new spionid polychaete, Rhynchospioaciliata sp. nov., was discovered in the fine sandy sediments of an intertidal habitat from Korean waters. The new species is considered a simultaneous hermaphrodite, but no brooding embryos were found in any of the specimens collected in this study. This species is unique in the absence of ciliation in the anteriormost chaetigers. Rhynchospioaciliata sp. nov. is morphologically most similar to Rhynchospiofoliosa Imajima, 1991 from Japan in having an elevation on the prostomium, conspicuously large and foliaceous branchiae, and intersegmental lateral pouches. However, the new species differs from the latter by the following characteristics: (1) large and lanceolate notopodial postchaetal lamellae of chaetiger 1, (2) transverse ciliated bands and ciliation on the inner branchiae absent in anteriormost chaetigers, and (3) pygidium with one pair of ventral cirri and numerous elongated dorsolateral cirri. Detailed description and illustrations of the new species are provided with molecular information on mitochondrial cytochrome c oxidase subunit I (COI), 16S ribosomal DNA (rDNA), nuclear 18S rDNA, and 28S rDNA.

Revision of Chloeia Savigny in Lamarck, 1818 from tropical American seas (Annelida, Amphinomidae).

The species of Chloeia Savigny in Lamarck, 1818 include some of the most colorful amphinomid annelids in tropical seas. Their pigmentation patterns can be diagnostic but because some pigments may fade after ethanol preservation, they have been disregarded as useful taxonomic characters. In this contribution we revise the tropical American species of Chloeia, and we confirm stability of pigmentation patterns, the presence of cirriform branchiae along a few anterior chaetigers, and emphasize the size of eyes and of ventral cirri as diagnostic characters. Five species are redescribed and two ones are newly described; the redescribed species are C. entypa Chamberlin, 1919 from Western Mexico, C. euglochis Ehlers, 1887 from the Grand Caribbean (reinstated), C. pinnata Moore, 1911 from Southern California (extended southwards in Western Mexico), C. pseudeuglochis Augener, 1922 from Pacific Costa Rica (includes several records for a colorful shallow water species in the Eastern Pacific), and C. viridis Schmarda, 1861 from the Grand Caribbean, which is restricted to specimens having a single, dorsal longitudinal T-shaped band. New species are Chloeia nuriae sp. n. from the Gulf of California, and C. paulayi sp. n. from the Gulf of Mexico . Two other species previously recorded for the region, C. conspicua Horst, 1910 and C. flava (Pallas, 1766) are briefly characterized in order to avoid future misidentifications. Further, C. candida Kinberg, 1857 from the Virgin Islands, is regarded as indeterminable. A key to identify tropical American species of Chloeia is also included.

Nephtyidae (Annelida: Polychaeta) from the Sea of Marmara and Black Sea, with descriptions of two new species.

The present paper deals with the diversity of nephtyid polychaetes (Nephtyidae) from the Sea of Marmara and the Black Sea. Three species belonging to two genera (Micronephthys and Nephtys) were found in the Black Sea (coast of Turkey) and six species belonging to three genera (Inermonephtys, Micronephthys and Nephtys) were found in the Sea of Marmara. The material includes two species new to science, Inermonephtys turcica n. sp. and Nephtys sinopensis n. sp., and a species record (Nephtys kersivalensis McIntosh, 1908) new to the Sea of Marmaras marine fauna. Nephtys sinopensis n. sp. is mainly characterized by having 14 geniculate chaetae in the postacicular position of the parapodia; digitiform antennae, palps, and ventral cirri at chaetiger 1 with swollen tips; small and cirriform branchiae present from chaetiger 4 to the end of the body; poorly developed parapodial prechaetal lamellae in median and posterior chaetigers and long ventral cirri along the body. Inermonephtys turcica n. sp. is mainly characterized by having cushion-like palps with digitiform tips; well developed neuropodial postchaetal lamellae; barred chaetae in preacicular position of the anterior and median parapodia; and branchiae first appearing between chaetiger 3 and 13 (depending on body size).

Morphology, ontogeny and molecular phylogeny of a new urostylid ciliate, Bakuella (Pseudobakuella) guangdongica n. sp. (Ciliophora, Hypotrichia) from southern China

The morphology, morphogenesis, and molecular phylogeny of Bakuella (Pseudobakuella) guangdongica n. sp., isolated from southern China, were investigated. The new species is characterized by a body length of 150–225 μm in vivo; 35–42 adoral membranelles; 3–5 buccal, two frontoterminal, 7–12 transverse and two pretransverse ventral cirri; midventral complex comprised of 10–20 pairs and two rows extending to transverse cirri; posterior part of marginal rows slightly overlapping; colorless cortical granules about 1 μm across, arranged in small groups; soil habitat. Its main ontogenetic features are: (1) in the proter, the parental adoral zone of membranelles is completely renewed by new structures; (2) in the opisthe, the oral primordium originates apokinetally, some old midventral cirri join the formation of frontoventral-transverse cirral anlagen; (3) the anlagen for marginal rows and dorsal kineties develop intrakinetally; and (4) the numerous macronuclear nodules fuse into a single mass before dividing. Phylogenetic analyses based on the SSU rDNA sequence suggest the non-monophyly of the genus Bakuella.

Some morphologically distinguishable hypotrich ciliates share identical 18S rRNA gene sequences – taxonomic insights from a case study onOxytrichaspecies (Protista, Ciliophora)

AbstractModern taxonomic studies of ciliated protozoa require both morphological and molecular data. One dilemma is how to distinguish morphologically similar species with few nucleotide differences in the widely used marker, the 18S rRNA gene. In the present study, two Oxytricha species were morphologically documented using light and electron microscopy. The mitochondrial cytochrome c oxidase subunit I (COI) gene and a fragment of the rRNA gene covering the 18S-ITS1-5.8S-ITS2-28S rRNA gene regions were sequenced. Phylogenetic analyses of all available Oxytricha granulifera-related populations were performed to reveal the internal relationships of this group. We described a new species, Oxytricha atypica sp. nov., distinguished from its congeners by having seven postoral ventral cirri resulting from the additional fragmentation of anlage V during ontogenesis. Although their 18S rRNA genes differ by only one nucleotide, divergence of the COI gene is as high as 11.8% between O. atypica and the closely related species, O. granulifera. All but one of the COI nucleotide substitutions were synonymous. We documented the highly conserved nature of the 18S rRNA gene in the morphospecies of Oxytricha. Based on these findings, we speculate that O. granulifera contains cryptic species or morphospecies needing further characterization, and new insights for the taxonomy of hypotrich ciliates are also discussed.

<p class="ZootaxaTitle"><strong>Transformative nototchaetae: larval development and metamorphosis in <em>Chrysopetalum </em>spp. (Chrysopetalinae: Chrysopetalidae: Annelida)</strong></p>

The morphology of an early nectochaete larva belonging to Chrysopetalum sp. is aligned with that of a planktotrophic larva at a crucial stage of benthic settlement: an entire provisional spinose notochaetal scleritome, large episphere with prostomial nascent sensory structures and larval podia and cirri of the anterior two segments in transition. Morphological sequences of post-larvae and juveniles, common to a number of Chrysopetalum species, indicate that long, slender, provisional, camerate notochaetal spines are replaced during metamorphosis and growth with an entire adult, camerate notochaetal scleritome consisting of broad paleae with internal, longitudinal ribs. The Chrysopetalum sp. six segment larva supports achaetous notopodia I and chaetous notopodia II, each with a pair of dorsal cirri, ie. 4 cirri in total; segment II has acirrose neuropodia. Individuals of post-larvae and juvenile Chrysopetalum species, 8–15 segments, possess a total of 6 cirri on segments I and II: segment I with a pair of tentacular dorsal cirri and the formation of a pair of tentacular ventral cirri, and segment II comprising a pair of dorsal cirri, spinous notochaetae and acirrose neuropodia. During metamorphosis the acirrous neuropodia of segment II are reabsorbed and replaced in stages with a pair of ventral tentacular cirri until the adult state is achieved: achaetous segment 1 with two pairs of tentacular cirri and segment II similar, ie. total of 8 cirri. The cirri arrangement of segments I and II before final metamorphosis in post-larval stages of Chrysopetalum species is, interestingly, that described for adults in the majority of other Chrysopetalinae taxa. Ontogenetic developmental processes of formation and loss of acirrose neuropodia and replacement of spinose larval notochaetae with adult paleae observed in Chrysopetalum species are compared with species of other taxa of the Chrysopetalinae.

Pilargidae (Annelida: Phyllodocida) from coastal and deep waters of the Southwestern Atlantic, with descriptions of two new species.

We describe seven species of Pilargidae from the coast and deep sea (300-1400 m deep) of southeastern Brazil, belonging to the genera Ancistrosyllis McIntosh, 1878, Cabira Webster, 1879, Glyphohesione Friedrich, 1950, Hermundura Müller, 1858, and Pilargis Saint-Joseph, 1899. Of those, two are new species (Glyphohesione campensis sp. nov. and Pilargis falconae sp. nov.) and two are new records of Ancistrosyllis for Brazil. Glyphohesione campensis sp. nov. is distinguished from its congeners by fewer neurochaetae, the anteriormost appearance of first notopodial spines, and intermediate relative length of dorsal and ventral cirri. Pilargis falconae sp. nov. is diagnosed by the presence of parapodial glands from the first chaetiger on the dorsal surface and from the sixth chaetiger on the ventral surface; and neurochaetae smooth capillaries and limbates with unidentate tips. Keys to pilargid species reported from, or likely to occur in, Brazilian waters are provided.

Morphology and molecular phylogeny of two new soil ciliates, Hemiurosomoida warreni nov. spec. and Hemiurosoma clampi nov. spec. (Ciliophora, Hypotrichia) from Tibet

Two novel hypotrichous ciliates, Hemiurosomoida warreni nov. spec. and Hemiurosoma clampi nov. spec., isolated from soil in the Lhalu Wetland and Motuo Virgin Forest in Tibet, respectively, were investigated using live observation and protargol staining. Hemiurosomoida warreni nov. spec. strongly resembles the type species H. longa but can be distinguished by its body size in vivo (110–145 × 30–40 μm vs. 50–100 × 18–40 μm), number of adoral membranelles (25–38 vs. 15–22), and numbers of right (29–39 vs. 14–23) and left (26–35 vs. 13–23) marginal cirri, transverse cirri (3 vs. 4 or 5) and macronuclear nodules (4–8 vs. 2). Hemiurosoma clampi nov. spec. is characterized by its vermiform body shape, colourless cortical granules distributed in irregular rows, two macronuclear nodules, three frontal cirri, one buccal cirrus, four frontoventral cirri ranged in a line, two transverse cirri, lacking postoral ventral and pretransverse ventral cirri, and marginal rows that are not posteriorly confluent. Phylogenetic analyses based on SSU rDNA gene sequences suggest that Hemiurosomoida is not monophyletic. A close relationship is revealed between Hemiurosomoida warreni nov. spec., Parakahilella macrostoma, Hemiurosoma clampi nov. spec., and the type species Hemiurosoma terricola. As expected, all these species are classified within the “non-oxytrichid Dorsomarginalia”.

Morpholino-Mediated Knockdown of Ciliary Genes in Euplotes vannus, a Novel Marine Ciliated Model Organism.

Cilia are highly conserved organelles present in almost all types of eukaryotic cells, and defects in cilia structure and/or function are related to many human genetic disorders. Single-celled ciliated protists, which possess diverse types of cilia, are remarkable model organisms for studying cilia structures and functions. Euplotes vannus is a representative ciliate with many intriguing features; for example, it possesses extensively fragmented somatic genomes and a high frequency of + 1 programmed ribosomal frameshifting. However, the molecular mechanisms underlying these remarkable traits remain largely unknown, mainly due to the lack of efficient genetic manipulation tools. Here, we describe the first application of a morpholino-based strategy to knockdown gene expression in E. vannus. Through interfering with the function of two ciliary genes, ZMYND10 and C21ORF59, we showed that these two genes are essential for the ciliary motility and proliferation of E. vannus cells. Strikingly, both ZMYND10- and C21ORF59-knockdown cells developed shorter cilia in the ventral cirri, a special type of ciliary tuft, suggesting a novel role for these genes in the regulation of cilia length. Our data provide a new method to explore gene function in E. vannus, which may help us to understand the functions of evolutionarily conserved cilia-related genes as well as other biological processes in this intriguing model.

Glycera sheikhmujibi n. sp. (Annelida: Polychaeta: Glyceridae): A New Species of Glyceridae from the Saltmarsh of Bangladesh

A new species of glycerid polychaete, Glycera sheikhmujibi, is described from the saltmarsh on the central coast of Bangladesh. The species is identified based on morphological characteristics using both a light microscope and scanning electron microscope (SEM). The species is characterized by the presence of three distinct types of proboscideal papillae: type 1 papillae (conical with three transverse ridges), type 2 (conical with a straight, median, longitudinal ridge), and type 3 (round, shorter, and broader, with a straight, median, longitudinal ridge). It has a Y-shaped aileron with gently incised triangular base, almost equal-size digitiform noto- and neuropodial lobes in the mid-body, and long ventral cirri at the posterior end. The new species is compared with its related species, previously described from the Bay of Bengal region. A key to all these species is provided.

Molecular and morphometric analyses identify new lineages within a large Eumida (Annelida) species complex

AbstractWe report on two new lineages of the Eumida sanguinea complex from Great Britain and describe one of them as a new species using a multilocus approach, including the mitochondrial DNA COI‐5P and the nuclear markers ITS (ITS1, 5.8S rRNA and ITS2) and 28S rRNA. The molecular analysis placed Eumida mackiei sp. nov. in a monophyletic clade with 19.1% (COI), 10.1% (ITS) and 1.7% (28S) mean distance to its nearest neighbour. Molecular diagnoses were also applied to nine lineages within the E. sanguinea complex. This was complemented with morphometric data employing multivariate statistical analysis and the incorporation of statistical dissimilarities against three other described species from the complex. Eumida mackiei sp. nov. can be distinguished from E. notata and E. maia by the larger distance between the eyes and differences in morphometric proportions mainly in the dorsal and ventral cirri as well as in the prostomial appendages. E. sanguinea sensu stricto failed to produce a cluster of its own in the morphometric analysis, probably due to juvenile bias. Integrative taxonomy provided strong evidence to formally describe a new cryptic species that can now be used in biomonitoring or other relevant ecological research.