Dorsal Papillae Research Articles

Proalesamplus sp. nov., a new monogonont rotifer with a large epipharynx from Korea (Rotifera, Proalidae).

The family Proalidae Harring & Myers, 1924, includes four genera and 53 species, distributed across all eight biogeographic realms and inhabiting various environments, including freshwater, saltwater and terrestrial environments. The genus Proales, the largest within Proalidae, encompasses 41 species characterised by diverse morphological traits. In Korea, the presence of Proalidae has been documented with five known species: Bryceellaperpusilla Wilts, Martínez Arbizu & Ahlrichs, 2010, B.stylata (Milne, 1886), B.tenella (Bryce, 1897), Proalesfallaciosa Wulfert, 1937 and Proalinopsiscaudatus (Collins, 1872). A new species, Proalesamplus sp. nov., is the 42nd species within the genus Proales. This species exhibits unique morphological characteristics in the trophi, particularly in the epipharynx, which are distinctive enough to prevent misidentification with other Proales species. The habitus of the new species bears some resemblance to P.phaeopis Myers, 1933, sharing features, such as an elongated and fusiform body, two eyespots, a single foot pseudosegment, two short toes and the absence of a dorsal papilla between the toes. However, the epipharynx of the two species is markedly different. The unique epipharynx characteristic of this new species is unparalleled within the genus Proales.

Synallactesmcdanieli sp. nov., a new species of sea cucumber from British Columbia, Canada and the Gulf of Alaska, USA (Holothuroidea, Synallactida).

The family Synallactidae comprises mostly deep-sea forms and is the least-studied large taxon amongst deep-sea cucumbers. They are part of the abyssal megafauna and play an important role in modifying the sediment landscape and structuring the communities that live within it. The family embraces the genus Synallactes, which contains approximately twenty-five species from the Pacific, Atlantic (six species), Indian (seven species) and Antarctic Oceans (one species). Synallactesmcdanieli sp. nov. is described from the Northeast Pacific, Knight Inlet, British Columbia, Canada to Kodiak Island, Gulf of Alaska, USA, at depths from 21 to 438 m. This new species is unique amongst the species of the genus Synallactes because of the number and arrangement of dorsal papillae, number of Polian vesicles, together with the entire ossicle arrangement. In addition, this species has the shallowest bathymetric distribution ever recorded for this genus.

Biology, morphology and taxonomy of a snail-feeding leech from North Carolina, USA, provisionally identified as Helobdella lineata (Verrill, 1874) (Glossiphoniidae): First evidence for extra-oral digestion in the Hirudinea

This is a twelve-year longitudinal study of a common snail-feeding leech indigenous to the Albemarle region of northeastern North Carolina, USA. Based on contents of this paper the species is provisionally identified as Helobdella lineata (Verrill, 1874). For all practical purposes this is the first comprehensive description of this species. Particular attention is focused on variability of its dorsal papillae and variable pigment patterns within the Albemarle population. A total of 404 specimens were collected from 25 collecting stations in disparate parts of the region. Specialised leech traps set in these swamps were monitored regularly yielding unprecedented information on its morphology, ecology and general biology. This study recognises four principal pigment variants within the Albemarle region which, based on dissections, appear to represent a single biological species. Moreover, limited observations suggest that pigment variability is attributable primarily to adaptive camouflage to local surroundings. Methodologically it is emphasized in this paper that variable traits cannot serve as key taxonomic anchors. A proposed alternative diagnosis for identifying H. lineata is based entirely on more rigorous, non-variable characters. A significant finding is that H. lineata is most meaningfully understood in terms of specialist adaptation to feeding on snails. Furthermore, it is proposed that such adaptation required a major evolutionary shift within the foregut of this species. Evidence is presented that H. lineata uses uniquely large salivary cells to dissolves solid snail tissue into a semi-fluid state before ingestion via a specialised proboscis. This is the first example of extra-oral digestion in the Hirudinea.

Pseudocryptic diversity and species boundaries in the sea cucumber Stichopus cf. horrens (Echinodermata: Stichopodidae) revealed by mitochondrial and microsatellite markers

Morphologically cryptic and pseudo-cryptic species pose a challenge to taxonomic identification and assessments of species diversity and distributions. Such is the case for the sea cucumber Stichopus horrens, commonly confused with Stichopus monotuberculatus. Here, we used mitochondrial cytochrome oxidase subunit I (COI) and microsatellite markers to examine genetic diversity in Stichopus cf. horrens throughout the Philippine archipelago, to aid species identification and clarify species boundaries. Phylogenetic analysis reveals two recently diverged COI lineages (Clade A and Clade B; c. 1.35–2.54 Mya) corresponding to sequence records for specimens identified as S. monotuberculatus and S. horrens, respectively. Microsatellite markers reveal two significantly differentiated genotype clusters broadly concordant with COI lineages (Cluster 1, Cluster 2). A small proportion of individuals were identified as later-generation hybrids indicating limited contemporary gene flow between genotype clusters, thus confirming species boundaries. Morphological differences in papillae distribution and form are observed for the two species, however tack-like spicules from the dorsal papillae are not a reliable diagnostic character. An additional putative cryptic species was detected within Clade B-Cluster 2 specimens warranting further examination. We propose that these lineages revealed by COI and genotype data be referred to as Stichopus cf. horrens species complex.

Podia histology and ultrastructure of tropical sea cucumber Phyllophorus sp. (Phyllophoridae) and Colochirus quadrangularis (Cucumaridae) from Madura Strait, Indonesia

Abstract. Winarni D, Eridianti SA, Suhargo L, Khaleyla F, Wirawati I. 2023. Podia histology and ultrastructure of tropical sea cucumber Phyllophorus sp. (Phyllophoridae) and Colochirus quadrangularis (Cucumaridae) from Madura Strait, Indonesia. Biodiversitas 24: 5685-5692. Phyllophorus sp. and Colochirus quadrangularis are sea cucumber species found in Madura Strait, East Java, Indonesia. Both species possess distinctive podia structures, which are protrusions on their body walls resembling spines. These structures serve as tube feet for movement (ventral podia) and sensory organs (dorsal papillae). This research aimed to compare the podia structures of Phyllophorus sp. and Colochirus quadrangularis. Five samples of each species were collected from the Madura Strait. Histological slides were prepared for the papillae (dorsal) and podia (ventral) on the anterior, median, and posterior body sections. Simultaneously, an examination of the ultrastructure was conducted using a scanning electron microscope (SEM). Analysis revealed differences between the podia of the two species. Phyllophorus sp. papillae had semi-flat tips, were non-suckered (SFNS), and exhibited squamous to short columnar epithelia, while their tube feet had flat tips, were non-suckered, and had columnar epithelia. Papillae were denser than tube feet. Conversely, C. quadrangularis papillae were pointed and non-suckered (PNS), and tube feet were flat and non-suckered (FNS). Notably, ossicle-dense areas in C. quadrangularis papillae had a pyramidal shape. In summary, the histology and ultrastructure of podia in these species displayed significant differences, highlighting their unique characteristics. They also imply to the adaptation biology of sea cucumber in Indonesian waters.

Epiperipatus puri sp. nov., a new velvet worm from Atlantic Forest in Southeastern Brazil (Onychophora, Peripatidae).

Epiperipatus ohausi (Bouvier, 1900) is the first species known from Rio de Janeiro, and more than 120 years later a new species is described in the state of Rio de Janeiro (RJ). In this study, we describe the second species in the state of Rio de Janeiro, which we are naming in honor of the indigenous population called puri who resided in southeastern coastal Brazil. The species can be diagnosed mainly by large dorsal primary papillae close to the insertion of the legs drawing a light band from the anterior to the posterior region of the body, and large dorsal primary papillae alternating on the dorsal plicae. Moreover, they are recognized in vivo by the color of the diamond-shaped marks brownish orange on the dorsal portion of the body. Epiperipatus puri sp. nov. morphologically seems to be related to Epiperipatus acacioi (Marcus & Marcus, 1995) by the shape of the primary papillae apical piece and to E. ohausi by the resemblance of dorsal papillae. The phylogeny shows a close relationship between the new species and E. ohausi in a clade with a still undescribed species from Rio de Janeiro, Brazil located within the Atlantic Forest, one of the most threatened biomes in the world.

Two new species of the bathyal holothurian genus Pannychia (Elasipodida, Laetmogonidae) from Japanese waters.

Sea cucumbers are one of the most common large animals in the deep-sea benthic communities, and those of the genus Pannychia are particularly abundant in the bathyal North Pacific Ocean. In Japanese waters, three species of Pannychia have been reported, mainly from the northern and eastern parts of the country. Here, we describe two new species from the western part of Japan. These two new species were placed in Pannychia by the presence of dorsal papillae on the ventrolateral radii and the presence of large wheel ossicles with rim teeth. They are distinguished from all other nominal species of Pannychia on the basis of the morphological characteristics of their body wheel ossicles. Pannychia nagasakimaruae sp. nov. has a unique ossicle composition in its dorsal and ventral body walls: four forms of wheel ossicles. Pannychia rinkaimaruae sp. nov. differs from other congeners in its small wheel ossicles in the dorsal and ventral body walls, which have conical rim teeth. We barcoded partial COI gene sequences from holotypes and paratypes of two new Japanese species. Our molecular phylogenetic analysis showed that these two new morphologically recognized Japanese species form distinct clades separated from other Pacific Pannychia species, so that the two new Japanese species were also supported by genetic results. In addition, we describe and visualize the poorly calcified calcareous rings of the two new species using X-ray μCT system, a useful method for observing such structures, which are important structures in holothurian anatomy.

Artificial rearing of Actinopyga lecanora (Holothuroidea: Holothuriida) with spawning induction using relaxin: Lecithotrophic short larval period

Artificial rearing techniques of larvae and juveniles of the tropical sea cucumber, Actinopyga lecanora were developed for the first time. Broodstock individuals were collected in Yaeyama Islands, Okinawa, subtropical Japan and sorted by the gonad maturity which was determined by biopsy. An artificially-synthesized relaxin peptide, originated from Holothuria (Metriatyla) scabra, was injected into the coelomic fluid of mature A. lecanora at amounts of 3 × 10−9 to 10 × 10−9 mol kg−1 body weight, which successfully induced spawning in 10 of 14 females and 3 of 3 males after 26–70 min. The number of eggs spawned per one female individual ranged 2.2–9.5 × 105. The mean diameter of oocytes of A. lecanora individuals which spawned by the induction was 324 ± 13 μm, much larger than those of sea cucumber species having a planktotrophic larval stage. The embryo hatched during gastrula, and the larva metamorphosed to planktonic auricularia followed by doliolaria and finally settled into the benthic stage as pentactula. Time after fertilization to settlement was 4–8 days when larvae were reared in 5–500 L tanks at 26–28 °C, which is one of the shortest development periods among sea cucumbers. Although larvae were supplied with Chaetoceros gracilis cells in most rearing batches, the larvae were later confirmed as lecithotrophic (non-feeding) as (1) larvae were successfully reared until settlement without feeding, and (2) chlorophyll a fluorescence of C. gracilis was not incorporated into the larval intestine as observed under fluorescence microscopy. Auricularia larvae showed poor development of lateral arm protrusion and did not form hyaline spheres. Initial rearing densities under 0.4 larva mL−1 resulted in relatively good survival. Settling larvae were retrieved using polycarbonate corrugated sheets on which periphytic diatoms had been grown beforehand. Survival from hatching to 2 months after settlement was 1.0–1.8%, comparable with values reported for other sea cucumbers. Postsettled juveniles became orange-colored with black dorsal papillae in 50 days after settlement and subsequently gradually obtained a dark green-brown dorsal pigment. Juveniles having anal teeth and adult-like color pattern appeared from 4 months after settlement. Growth of the settled juveniles was 91.8 ± 1.5 μm day−1 from Jun to Dec, reaching 15.11 ± 5.63 mm long in 170 days, while the juveniles negatively grew during winter from Dec to Feb. The lecithotrophic short larval period of A. lecanora has potential for low-cost seed production, which is advantageous for development of aquaculture and restocking.

Rehabilitation of two deep-sea holothurian species in genus Pannychia from the northwest Pacific Ocean

Genus Pannychia Théel, 1882 is one of the dominant sea cucumber genus in the bathyal zone of the North Pacific Ocean. Previously seven species/subspecies were described in Pannychia and another closest genus Laetmophasma Ludwig, 1894 from all over the Pacific Ocean, but all of them were synonymized into Pannychia moseleyi Théel, 1882, which is currently single valid species in the Pacific Ocean. In this study, we rehabilitate Pannychia henrici Ludwig, 1894 and Pannychia virgulifera Ohshima, 1915 as separate species from the northwest Pacific Ocean, which were originally established as geographical variation/subspecies of P. moseleyi. This study includes molecular phylogenetic analysis based on specimens collected from broad part of the northwest Pacific Ocean, and morphological comparison including re-examination of both subspecies type specimens. Genetically these two northwest Pacific taxa and P. moseleyi are clearly distinguished from each other, which corresponded to different characteristics of dorsal papillae arrangement, the body coloration, and the ossicle density in dorsal body wall. As a result of rehabilitation of P. henrici and P. virgulifera, the genus Pannychia was reorganized to 4 valid species, but P. moseleyi still include large morphological variations, and it is necessary to a further taxonomic revision. Additionally, P. henrici and P. virgulifera particularly represent an example of importance of body coloration in taxonomy of the deep-sea Holothuroidea.

Holothuria (Lessonothuria) coronata sp. nov. (Echinodermata, Holothuroidea), a new species of sea cucumber from Socorro Island, México

?Holothuria (Lessonothuria) coronatasp. nov. occurs in depths of 5–10 m off the Mexican Pacific coast at the Revillagigedo Archipelago. It is clearly distinguished from other species of the subgenus by the presence of tables with a circular disc and big peripheral holes, sometimes with a second series of peripheral ones, a disc with a spiny or smooth rim and a spire crossed by a single cross-beam, dorsal papillae, and ventral tube feet with curved supporting rods with a spiny edge.

Histologic Examination of a Sea Pig (Scotoplanes sp.) Using Bright Field Light Microscopy

Sea pigs (Scotoplanes spp.) are deep-sea dwelling sea cucumbers of the phylum Echinodermata, class Holothuroidea, and order Elasipodida. Few reports are available on the microscopic anatomy of these deep-sea animals. This study describes the histologic findings of two, wild, male and female Scotoplanes sp. collected from Monterey Bay, California. Microscopic findings were similar to other holothuroids, with a few notable exceptions. Sea pigs were bilaterally symmetrical with six pairs of greatly enlarged tube feet arising from the lateral body wall and oriented ventrally for walking. Neither a rete mirabile nor respiratory tree was identified, and the large tube feet may function in respiration. Dorsal papillae protrude from the bivium and are histologically similar to tube feet with a large, muscular water vascular canal in the center. There were 10 buccal tentacles, the epidermis of which was highly folded. Only a single gonad was present in each animal; both male and female had histologic evidence of active gametogenesis. In the male, a presumed protozoal cyst was identified in the aboral intestinal mucosa, and was histologically similar to previous reports of coccidians. This work provides control histology for future investigations of sea pigs and related animals using bright field microscopy.

Ultra structure of second instar larva of Hemipyrellia ligurriens (Wiedemann) (Diptera: Calliphoridae), a forensically important blow fly species from India

Ultra structural characters of second instar larvae of Hemipyrellia ligurriens are elucidated through micrographs (Scanning Electron Microscope). Morphological details of maxillary palpi, antennae, oral cirri, facial mask, labial lobe, spinulations, and papillae of anal segment are described. Oral cirri are ten in number, arranged bilaterally on each side of the functional mouth opening and gently curved medially. The labial lobes are distinctively demarcated with fleshy projections antero–ventrally and have a characteristic shape. Thoracic spines have a bulbous base, slender sharp tips and are directed backwards. Prominent dorsal and ventral anal papillae with projected tips and broad conical base were present surrounded by microtrichia. The ultrastructure details of H. ligurriens would help in the rapid and accurate identification of the species in forensic investigations and to estimate time since death in medico legal cases. This is the first report on the ultra-structural features of H. ligurriens.

Morphological and molecular characterization of Butlerius butleri Goodey, 1929 (Nematoda: Diplogastridae) from South Africa: First report.

Two populations of a Butlerius species were recovered from compost in two gardens in Potchefstroom, North-West Province, South Africa. Although the genus has previously been reported from South Africa, no species of the genus has ever been identified in the country. Based on morphological, morphometric, and molecular studies, the specimens were identified as Butlerius butleri and are herein reported for the first time from South Africa. The South African specimens are 1,082 to 1,423 µm long, a = 40.8 to 47.6; b = 4.7 to 5.8; c = 4.0 to 6.0; c′ = 117 to 16.3; V = 44 to 47%. Cuticle with evenly spaced punctations. Reproductive system didelphic, amphidelphic, both branches equal in length. Four large glands opening into proximal part of uterus. Males with prominent sphincter present in mid-region of vas deferens. Spicules 36 to 43 μm long, gubernaculum 23 to 31 µm long, nine pairs of genital papillae, three pre-cloacal and six post-cloacal, formula: v1, v2, v3d/v4, ad, ph, v5, 6, 7, pd. The v5, 6, 7 clusters greatly separated, left subventral group at level of phasmid, right subventral group at level of posterior dorsal papilla. Although there were some differences, the South African populations of the species compare well to all know descriptions of the species. Phylogenetic analysis based on partial small subunit (SSU) rDNA sequences showed that both South African populations of B. butleri are in a maximally supported sister relation with an Iranian population of this species. Based on large subunit (LSU) rDNA sequences, the two populations of B. butleri clustered together in a well-supported clade.

Batracobdelloides bangkhenensis sp. n. (Hirudinea: Rhynchobdellida), a new leech species parasite on freshwater snails from Thailand.

A new snail-eating leech, Batracobdelloides bangkhenensis sp. n., was discovered at Kasetsart University, Bangkhen Campus, Bangkok, Thailand. This species is found free living in the benthic zone of ponds; feeds on freshwater snails, including Bithynia siamensis siamensis, Indoplanorbis exustus, Radix rubiginosa, Physella acuta, and Pomacea canaliculata; and uses a shell as a shelter during the parental care period, with a colony of 7-15 juvenile individuals held on the venter inside the shell of host. Batracobdelloides bangkhenensis displays distinct morphological characters, including a rice-shaped body showing transparency, cephalization, two eye pairs merged on somite III, an anterior sucker twice as large as the cephalic region, a central mouth in the anterior sucker, seven light brown transverse rows in the neck region, absent dorsal papillae, rich green pigments on the dorsum, a male gonopore on XIIa2/XIIa3 (27-28), a female gonopore on XIIIa1/XIIIa2 (29-30), and diffuse aggregations of minute, spherical salivary glands in the neck region. Comparisons of the COI and COI-ND1 genes showed a monophyletic clade for Batracobdelloides, and the phylogenetic tree of the COI gene also indicated that B. bangkhenensis is distinct from other species in the genus, with strong support values.

Two new species of Sphaerodoridae (Annelida) from the Gulf of Thailand.

Despite being a great species-rich area, the Gulf of Thailand has been relatively poorly studied and new species are awaiting to be described. In the present study two new species of Sphaerodoridae (Annelida), Geminofilum thailandica sp. nov. and Sphaerodoridium songkhlaensis sp. nov. were collected in shallow soft bottoms at Songkhla Sea. Geminofilum thailandica sp. nov. is characterised by bearing sessile and elongated dorsal macrotubercles, arranged in two transverse rows per segment, lacking other dorsal papillae, having parapodia with a single papilla at the base and compound chaetae with blades 4-6 times as long as wide and serration showing variation within fascicles. Sphaerodoridium songkhlaensis sp. nov. can be distinguished from other congeners by the singular morphology of the short stalked dorsal macrotubercles as inverted cones, with a conspicuous rim encircling the flattened distal surface, and two longitudinal rows of smaller sessile tubercles, as inverted cones, along ventrum, with four pairs of tubercles per segment. Chaetae show variation in the serration within fascicles. The present study highlights the need for further biodiversity studies on benthic communities in this area.

A new species of Streblospio (Polychaeta: Spionidae) from the northern Adriatic Sea (Mediterranean Sea).

The present study describes a new species of spionid polychaete, Streblospio eridani n. sp., from the Italian coasts of the Northern Adriatic Sea (Mediterranean Sea). This new spionid species was recorded from shallow lagoon and marine habitats: the soft bottoms of the Sacca di Goro (Po River Delta), on October 2017, and the Lido di Dante (Emilia Romagna), between 2016 and 2017. The re-assessment of spionid specimens from other lagoon systems (the Valli di Comacchio and the Valle di Gorino) led us to recognize the presence of this species in the northern Adriatic Sea since 2009. Streblospio eridani n. sp. had low occurrence and density at the marine site Lido di Dante and at the lagoon sites Valli di Comacchio and Valle di Gorino; whereas it reached the highest density of 21,213.3 ind. m-2 at the Sacca di Goro. Morphologically this new species is characterized by dorsal (occipital) papilla on the first chaetiger, sabre chaetae and hooded hooks first appearing on chaetigers 7, hooks with 4-5 pairs of small secondary teeth, pygidium with ventral lappets, and brooding branchiate structures between chaetigers 13 and 28. In the phylogenetic reconstruction, based on the mitochondrial cytochrome c oxidase subunit I (COI) gene, the Adriatic taxon results clearly indicate that this is distinct from the other species of the genus and formed a well-supported clade with other Streblospio sp. specimens from India. Nucleotide divergences calculated between the Adriatic specimens and the other Streblospio species are higher than the intraspecific range reported for the genus and support the description of a new species. Morphological characters important for differentiation of the new species herein described from congeneric species are discussed and an updated key for Streblospio species is provided.

First record of a symbiotic relationship between a polyclad and a black coral with description of Anthoplana antipathellae gen. et sp. nov. (Acotylea, Notoplanidae)

The close relationship between a polyclad (Platyhelminthes, Rhabditophora, Polycladida) and the mesophotic Atlantic–Mediterranean black coral Antipathella subpinnata (Ellis & Solander, 1786) (Cnidaria, Hexacorallia, Antipatharia) is herein described for the first time. Worms, up to 50 mm long, are elongated with sparse dorsal papillae, an anterior, ruffled pharynx and caudal, well-separated gonopores. The bulbous vagina is connected to a very elongated Lang’s vesicle, while the male apparatus, hosting a cuticular penis papilla, consists in a muscular interpolated prostatic vesicle, formed by few chambers surrounding the ejaculatory duct, a major seminal vesicle and numerous spermiducal bulbs. These features, as well as the uniqueness of the symbiotic relationship and relative reproductive adaptations, support the description of a new taxon, Anthoplana antipathellae gen. et sp. nov. (Acotylea, Notoplanidae). The observed symbiosis is ascribable to exclusive inquilinism with some parasitic traits. The individuals, living in large numbers on the colonies, are highly cryptic thanks to a characteristic pigmentation and a wrapped habitus. They lay numerous annular yellow cocoons (rigid, nest-like structures containing the fertilised eggs), in single or multiple rows on the distal branches of the coral, temporarily denudated of coenenchyme. The occurrence of the polyclad is consistent with the Atlantic–Mediterranean geographical and bathymetrical distribution of the A. subpinnata forests as demonstrated by the analysed photo archive, and a summer reproductive peak can be hypothesised based on the temporal observations carried out in the study areas.

Psychropotid holothurians (Echinodermata: Holothuroidea: Elasipodida) of the tropical Western Pacific collected by the KEXUE expedition with description of one new species

ABSTRACTTwo holothurian species of the family Psychropotidae were collected by RV KEXUE during the cruise to tropical Western Pacific. One of them, Benthodytes manusensis is described as new to science. The new species has a broad brim and reddish light violet body, with three pairs of well-developed dorsal papillae, arranged in two single rows, evenly distributed. Body wall ossicles were comprised of rods and large crosses with a bipartite central apophysis. We also provide the Genbank accession numbers of partial sequences of 16S rDNA and mitochondrial cytochrome oxidase subunit I gene. In addition, notes are presented on the morphology and distribution of another species Psychropotes depressa (Théel).http://zoobank.org/urn:lsid:zoobank.org:pub:22B43A54-1B05-4812-A098-448A0044B49C

Benthodytes marianensis, a new species of abyssal elasipodid sea cucumbers (Elasipodida: Psychropotidae) from the Mariana Trench area.

Benthodytes marianensis sp. nov., is described from the Mariana Trench at the depth of 5567 m. This is the thirteenth species in Benthodytes Théel, 1882. The new species has a broad brim around the body, dark violet skin, 9 pairs of large dorsal papillae with other papillae of equal or smaller size situated elsewhere, forming two zigzag rows, and some minute papillae scattered around the anterior region. Body wall ossicles are rods, crosses with three or four arms and central apophyses, and crosses of an unusual type. Crosses with four arms and central bipartite, tripartite and tetrapartite apophyses and peculiar cross-shaped ossicles with high apophyses ending in two horizontal arms are present in the dorsum. Large rod-shaped ossicles with bipartite apophyses and crosses with three or four arms and rudimentary apophyses are present on the ventrum. B. marianensis is morphologically most similar to B. incerta, but it is distinguished from B. incerta by the number and arrangement of dorsal large papillae, the broad brim and details of ossicle morphology. The phylogenetic analyses based on (16S, COI) and nuclear genes (H3) all confirm the morphological identification.

New species of Dispio Hartman, 1951 and Streblospio Webster, 1879 (Polychaeta, Spionidae) from the coast of the Iberian Peninsula.

Re-assessment of spionid specimens from Iberian Peninsula initially assigned to Dispio uncinata Hartman, 1951 and Streblospio benedicti Webster, 1879 led to the recognition of two new species from the spionid genera Dispio and Streblospio from coasts around the Iberian Peninsula. Dispio elegans sp. nov. is characterised by having an oblanceolate-shaped prostomium. In addition, the first two notopodial postchaetal lamellae are serrated with digitiform papillae, the anterior neuropodial lamellae are smooth; all branchiae are almost completely fused to the notopodial lamellae, but with the tips free; the notochaetae on chaetiger 1 are smooth, alimbate capillaries; the ventral chaetae located in the position of the sabre chaetae on chaetigers 1-2 are smooth, alimbate capillaries, but becoming granulated on chaetiger 3; and the middle and posterior chaetigers are granulated and reticulated. Streblospio padventralis sp. nov. is characterized by lacking dorsal papillae between the branchiae of chaetiger 1; the hooks have 4-5 pairs of small teeth; sabre chaetae are present from chaetiger 3; the pygidium has two ventral lappets; and brooding structures are present in the coelomic cavities. We suggest raising the status of Streblospio benedicti japonica Imajima, 1990 to full species level as S. japonica Imajima, 1990. A key for Streblospio species is provided.