Order Valvatida Research Articles

New record of the wood-associated sea starCaymanostella, with notes on the phylogenetic position of the family Caymanostellidae (Asteroidea)

AbstractIn 2016, three specimens of Caymanostella were collected from the Kuril-Kamchatka Trench area at depths of 5101–5134 m. Comparative morphological analysis revealed that the new specimens are similar to Caymanostella spinimarginata, the most geographically distant species (Atlantic Ocean). The new specimens were identified as C. cf. spinimarginata. Multilocus genetic data were obtained for the family Caymanostellidae for the first time in this study. Molecular evidence based on the analyses of three mitochondrial and two nuclear markers recovers the family Caymanostellidae as a sister-taxon to Ophidiasteridae (order Valvatida). Phylogenetic data indicate that morphological features, which were previously used to imply asterinid, xyloplacid or korethrasterid affinities for the family Caymanostellidae, emerged independently. It is suggested that the family Caymanostellidae should be placed within the order Valvatida.

The first complete mitochondrial genome of the Northern Pacific deep-sea goniasterid sea star Ceramaster japonicus (Sladen, 1889) determined using NGS-based shotgun sequencing

The full mitogenome of an ethanol-preserved museum specimen of Ceramaster japonicus was determined using the NGS Illumina MiSeq platform. The specimen was collected from Tosa Bay, Japan, facing the Pacific Ocean (33.0781 N 134.0601 E), at 700 m depth in 2011. The mitogenome shows a typical metazoan genomic structure, with all of the 37 genes included in its 16,370 base-long mitogenome. We conducted phylogenetic analyses using a data set including 18 publicly available asteroids rooted against five ophiuroids as outgroups. The result confirms the position of C. japonicus in the order Valvatida. The complete mitogenome of C. japonicus reported here is the first reported for the family Goniasteridae Forbes, 1841.

The first complete mitochondrial genome from the family Solasteridae, Crossaster papposus (Echinodermata, Asteroidea)

The common sunstar, Crossaster papposus, belongs to the family Solasteridae whose ordinal classification has been unstable. Here, for the first time, we assembled and annotated the complete mitochondrial genome of the common sunstar, C. papposus Linnaeus, 1767. The circular genome of C. papposus is 16,335 bp in length and contains 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, a control region, and large and small ribosomal subunits. The overall genomic structure and gene arrangement were identical to the reported mitochondrial genomes of sea star species, and a phylogenetic analysis of 13 PCGs recovers a closest relationship with the derived cluster of the paraphyletic order Valvatida.

Complete mitochondrial genome of a sea star, Linckia laevigata (Echinodermata, Asteroidea, Valvatida, Ophidiasteridae)

We determined the complete mitochondrial genome sequences of an asteroid Linckia laevigata belonging to the order Valvatida. The complete mitogenome of L. laevigata was 16,371 bp in length and consisted of 13 protein-coding genes (PCGs), two rRNA, and 22 tRNA. The orders of PCGs and rRNAs were identical to those of the recorded mitogenomes of asteroids. Phylogenetic analyses placed L. laevigata as the sister group to the species of the other Paxillosida.

New record of a sea star of genus <i>Solaster</i> (Asteroidea: Valvatida: Solasteridae) from the East Sea, Korea

Asteroid specimens were collected using fishing nets from the East Sea, Korea. The specimens were identified as Solaster paxillatus Sladen, 1889, belonging to the family Solasteridae of the order Valvatida. This species can be distinguished from three other Korean Solaster species by having 10 arms; subambulacral spines comprising four or five near base of arm, six or seven in middle part, and five or six in distal part of arm; furrow spines comprising four or five near basal part and three or four in distal part of arm; and suboral spines comprising more than ten spinules. The morphological characteristics of this species were described with illustrations. Solaster paxillatus is first reported in marine fauna of Korea.

Complete mitochondrial genome analysis of Aquilonastra batheri (Echinodermata, Asteroidea, Valvatida)

In this study, we determined the complete mitochondrial genome sequences of Aquilonastra batheri. This is the first study on mitochondrial genome sequencing of the genus Aquilonastra belonging to the family Asterinidae, order Valvatida, and class Asteroidea. The complete mitogenome of A. batheri was 16,463 bp and consisted of 13 protein-coding genes (PCGs), 22 tRNAs, and two rRNAs. The orders of PCGs and rRNA genes were identical to those of nine recorded mitogenomes of asteroids. The phylogenetic tree determined by the maximum likelihood method revealed that A. batheri was clearly grouped with Patiria pectinifera, which belongs to the family Asterinidae.

Relaxin-like gonad-stimulating peptide is highly conserved in starfish Asterina pectinifera

Relaxin-like gonad-stimulating peptide (RGP) in starfish is the only known invertebrate peptide hormone responsible for final gamete maturation, rendering it functionally analogous to gonadotropins in vertebrates. Recently, RGP was purified from the radial nerves of starfish Asterina pectinifera, which belongs to the Order Valvatida in the Class Asteroidea. A. pectinifera is an endemic Japanese species, inhabiting rocky shores from northern to southern Japanese waters. This study examined whether genetic variation or polymorphism is found in RGP. Comparing cDNA sequences of RGP in A. pectinifera from 10 local populations in Japanese waters, we found that the coding DNA sequences (CDSs) were exactly the same. This result indicated that RGP is a highly conserved peptide in A. pectinifera. Furthermore, the CDS of RGP identified in Certonardoa semiregularis, which also belongs to Order Valvatida, was completely consistent with that of A. pectinifera. Thus, this also suggested that the chemical structure of A. pectinifera RGP is conserved among starfish of the Order Valvatida beyond species.

THE PROFILE OF BAMA BEACH BASED ON THE SUBSTRATE, THE PRESENCE OF SEAGRASS, CORAL LIFEFORM, AND ECHINODERMATA

Bama Beach is one of the most visited beaches in Baluran National Park, Situbondo. However, this beach does not have information of beach profile which is very important for managing coastal and marine resources. The aims of this research are to make beach profiles based on substrate, presence of seagrass, coral lifeforms, and Echinodermata. This research’s method is qualdrate transect. Five transects were made, roll meter pulled from the highest tides zone to the reef crest. The distance between each transect around 35–40 m. Plots 1x1 m2 were placed along each transect with 8-15 m gap between each plot. Geographical coordinates were noted for each plot so the results are data in those plots. The results are the dominant substrate in Bama Beach is sand and always mixed with gravel. Boulders specifically found in the highest tides zone and close to the reef crest. Seagrass can be found almost in all plots, about 10 to 250 m from the highest tides zone. The dominant coral lifeform on reef flat is coral submassive; then approaching the reef crest, the coral massive is the dominant one. At Bama Beach, was found 5 classes and 9 orders of Echinodermata. Asteroidea with order Valvatida and Spinulosida; Ophiuroidea with order Ophiurida; Echinoidea with order Camarodonta, Diadematoida, Stomopneustoida; Holothuroidea with order Aspidochirotida and Apodida; and Crinoidea with order Comatulida. Those orders live in all zones, which are sandy zone, seagrass zone, and coral reef zone.

The profile of Bama Beach based on the substrate the presence of seagrass coral lifeform and Echinodermata

Bama Beach is one of the most visited beaches in Baluran National Park, Situbondo. However, this beach does not have information of beach profile which is very important for managing coastal and marine resources. The aims of this research are to make beach profiles based on substrate, presence of seagrass, coral lifeforms, and Echinodermata. This research’s method is qualdrate transect. Five transects were made, roll meter pulled from the highest tides zone to the reef crest. The distance between each transect around 35–40 m. Plots 1x1 m2 were placed along each transect with 8-15 m gap between each plot. Geographical coordinates were noted for each plot so the results are data in those plots. The results are the dominant substrate in Bama Beach is sand and always mixed with gravel. Boulders specifically found in the highest tides zone and close to the reef crest. Seagrass can be found almost in all plots, about 10 to 250 m from the highest tides zone. The dominant coral lifeform on reef flat is coral submassive; then approaching the reef crest, the coral massive is the dominant one. At Bama Beach, was found 5 classes and 9 orders of Echinodermata. Asteroidea with order Valvatida and Spinulosida; Ophiuroidea with order Ophiurida; Echinoidea with order Camarodonta, Diadematoida, Stomopneustoida; Holothuroidea with order Aspidochirotida and Apodida; and Crinoidea with order Comatulida. Those orders live in all zones, which are sandy zone, seagrass zone, and coral reef zone.

A Newly Recorded Sea Star (Asteroidea: Valvatida) from Jejudo Island, Korea

Some asteroid specimens were collected from the subtidal zone near Gapado, Jejudo Island with fishing net on June 2010. Among them, Anseropoda petaloides (Goto, 1914) which belongs to the family Asterinidae of the order Valvatida turned out to be a new record from Korea. Morphological characters of this species collected at 130 m deep are redescribed with photographs. This species is characterized by its very thin body composed of plates imbricated into each other like scales. Twenty four asteroids are currently known from Jejudo Island, Korea.

An Ancient Repeat Sequence in the ATP Synthase β-Subunit Gene of Forcipulate Sea Stars

A novel repeat sequence with a conserved secondary structure is described from two nonadjacent introns of the ATP synthase beta-subunit gene in sea stars of the order Forcipulatida (Echinodermata: Asteroidea). The repeat is present in both introns of all forcipulate sea stars examined, which suggests that it is an ancient feature of this gene (with an approximate age of 200 Mya). Both stem and loop regions show high levels of sequence constraint when compared to flanking nonrepetitive intronic regions. The repeat was also detected in (1) the family Pterasteridae, order Velatida and (2) the family Korethrasteridae, order Velatida. The repeat was not detected in (1) the family Echinasteridae, order Spinulosida, (2) the family Astropectinidae, order Paxillosida, (3) the family Solasteridae, order Velatida, or (4) the family Goniasteridae, order Valvatida. The repeat lacks similarity to published sequences in unrestricted GenBank searches, and there are no significant open reading frames in the repeat or in the flanking intron sequences. Comparison via parametric bootstrapping to a published phylogeny based on 4.2 kb of nuclear and mitochondrial sequence for a subset of these species allowed the null hypothesis of a congruent phylogeny to be rejected for each repeat, when compared separately to the published phylogeny. In contrast, the flanking nonrepetitive sequences in each intron yielded separate phylogenies that were each congruent with the published phylogeny. In four species, the repeat in one or both introns has apparently experienced gene conversion. The two introns also show a correlated pattern of nucleotide substitutions, even after excluding the putative cases of gene conversion.

Chrispaulia, a new genus of mud star (Asteroidea, Goniopectinidae) from the Cretaceous of England

AbstractThe asteroid species Nymphaster radiatus Spencer is redescribed in detail and placed in a new genus, Chrispaulia. Newly collected associated ossicles including ambulacral, adambulacral, marginal, terminal and actinal plates demonstrate that this taxon is a member of the family Goniopectinidae (order Paxillosida, suborder Cribellina), rather than of the Goniasteridae (order Valvatida) as hitherto presumed. This is the first fossil record of the Goniopectinidae, which is a small and rather uncommon family in Recent seas. Living Cribellina are specialized deposit feeders which burrow into muddy substrates in moderately deep marine to abyssal environments. The restriction of C. radiatus to Cretaceous muds and marly chalks, taken in conjunction with morphological evidence, leads to the conclusion that this species had a similar life style. The occurrence of fossil Cribellina is reviewed and the Cretaceous (Campanian) genus Paleoctenodiscus from Mexico is assigned to the Porcellanasteridae. Copyright © 2005 John Wiley & Sons, Ltd.

Comparative Morphology of Tube Feet Among the Asteroidea: Phylogenetic Implications

Tube-foot morphology has been included among a variety of taxonomic criteria for the Asteroidea over the past twenty-five years. Other than a few families belonging to the order Paxillosida, which are thought to have pointed, non-suckered tube feet that are used for digging and burial in soft sediments, the presumption has been that asteroids have flat-tipped, suckered tube feet. This has become an accepted model despite the fact that the comparative morphology of asteroid tube feet has not been considered. In the present study we examine tube-foot morphology of 45 species of Asteroidea representing 19 families. Our analysis confirms that members of the Luidiidae and Astropectinidae (order Paxillosida) lack suckers on the tips of their pointed tube feet. We demonstrate that there is considerable variation in tube-foot morphology among members of the Asteroidea including an entirely new type of flat-tipped, non-suckered tube foot in species belonging to the order Valvatida. The external morphology of tube feet in species belonging to the order Velatida could not be distinguished from “typical” flat-tipped, suckered tube feet; nonetheless, histological sections revealed a distinctive internal morphology. Finally, we report the first observations of the tube-foot morphology of representatives of deep-sea asteroids belonging to the orders Notomyotida and Brisingida, a group that also lacks the typical flat-tipped, suckered tube-foot morphology. The results of our study demonstrate that the current tube-foot morphology model needs to be reconsidered, as there is considerably greater variation than was previously believed to be the case. Moreover, we conclude that while tube-foot morphologies show consistent similarities within orders, tube-foot morphology is less appropriate as a taxonomic character below this level.

Comparative Morphology of Tube Feet Among the Asteroidea: Phylogenetic Implications1

Tube-foot morphology has been included among a variety of taxonomic criteria for the Asteroidea over the past twenty-five years. Other than a few families belonging to the order Paxillosida, which are thought to have pointed, non-suckered tube feet that are used for digging and burial in soft sediments, the presumption has been that asteroids have flat-tipped, suckered tube feet. This has become an accepted model despite the fact that the comparative morphology of asteroid tube feet has not been considered. In the present study we examine tube-foot morphology of 45 species of Asteroidea representing 19 families. Our analysis confirms that members of the Luidiidae and Astropectinidae (order Paxillosida) lack suckers on the tips of their pointed tube feet. We demonstrate that there is considerable variation in tube-foot morphology among members of the Asteroidea including an entirely new type of flat-tipped, non-suckered tube foot in species belonging to the order Valvatida. The external morphology of tube feet in species belonging to the order Velatida could not be distinguished from “typical” flat-tipped, suckered tube feet; nonetheless, histological sections revealed a distinctive internal morphology. Finally, we report the first observations of the tube-foot morphology of representatives of deep-sea asteroids belonging to the orders Notomyotida and Brisingida, a group that also lacks the typical flat-tipped, suckered tube-foot morphology. The results of our study demonstrate that the current tube-foot morphology model needs to be reconsidered, as there is considerably greater variation than was previously believed to be the case. Moreover, we conclude that while tube-foot morphologies show consistent similarities within orders, tube-foot morphology is less appropriate as a taxonomic character below this level.

MOLECULAR PHYLOGENETIC ANALYSIS OF LIFE-HISTORY EVOLUTION IN ASTERINID STARFISH.

We analyzed phylogenetic relationships among 12 nominal species of starfish in the genera Patiriella and Asterina (Order Valvatida, Family Asterinidae), based on complete sequences for a mitochondrial protein coding gene (cytochrome oxidase subunit I) and five mitochondrial transfer RNA genes (alanine, leucine, asparagine, glutamine, and proline) (1923 bp total). The resulting phylogeny was used to test a series of hypotheses about the evolution of life-history traits. (1) A complex, feeding, planktonic larva is probably ancestral for these starfish, but this is not the most parsimonious reconstruction of ancestral larval states. (2) The feeding larval form was lost at least four times among these species, and three of these losses occurred among members of a single clade. (3) Small adult size evolved before both cases of hermaphroditism and viviparous brooding, but viviparity was not always preceded by an intermediate form of external brooding. (4) An ordered transformation series from feeding planktonic development to viviparous brooding has been predicted for starfish, but we could not find an example of this transformation series. (5) Viviparity evolved recently (< 2 Mya). (6) Both species selection and transformation of lineages may have contributed to the accumulation of species with nonfeeding development among these starfish. (7) Neither Asterina nor Patiriella are monophyletic genera. Larval forms and life-history traits of these starfish have evolved freely under no obvious constraints, contrary to the widely assumed evolutionary conservatism of early development.

On the affinities of three small sea-star families

Summary The Metrodiridae, Mithrodidae and Valvasteridae are monogeneric sea-star families of obscure affinities traditionally assigned to the generically and morphologically diverse order Spinulosida. Re-valuation of available information, combined with the use of new skeletal characters, has led to reassignment of Metrodira to the spinulosan family Echinasteridae, Mithrodia to the valvatan family Ophidiasteridae, and Valvaster to the family Asteropseidae. The Asteropseidae is in turn assigned to the order Valvatida.