A new genus of Syllidae (Polychaeta) from Western Australia

During a study carried out on the subfamily Exogoninae (Syllidae) from Australia, several specimens of a new genus and species were found in samples of dead coral substrate from Western Australia. They have long palps, fused except for a terminal notch, long median and two short lateral antennae, a single pair of short tentacular cirri, and short dorsal cirri, somewhat longer than the parapodial lobes. These characters resemble those of the genus Exogone Örsted, 1845. However, all these appendages are articulated. The chaetae are very similar to those of several species of Syllis Lamarck, 1818, having coarse spines on the margin of compound chaetal blades and truncated dorsal simple chaetae. Furthermore, the pharynx begins in chaetiger 3, posterior to the peristomium, as in many species of the genus Syllis; this condition does not occur in any described species of Exogone. The new genus is provisionally proposed to belong to the subfamily Syllinae, although it has some characters typical of the Exogoninae. Examination under the SEM shows another peculiar feature, the nuchal organs are distinctly laterally located. Within the Syllinae, only Paratyposyllis Hartmann-Schröder, 1962 has a single pair of tentacular cirri, but in that genus, the palps are only basally fused.     

Syllidae (Annelida, Polychaeta) from the Caribbean coast of Venezuela

Venezuela possesses a great variety of coastal environments allowing for a high diversity of marine species. However, systematic studies on marine invertebrates are scarce, especially on polychaetes. The family Syllidae is poorly known, and only 14 genera and 42 species have been reported from this country. A total of 13 genera and 26 species the Syllidae were identified from benthic samples collected on different substrata of the northeastern coast of Venezuela. Of these, seven genera and 16 species constitute new records for Venezuela: Odontosyllis guillermoi, Syllides floridanus, Salvatoria clavata, Salvatoria limbata, Sphaerosyllis longicauda, Parapionosyllis longicirrata, Trypanosyllis parvidentata, Trypanosyllis vittigera, Opisthosyllis sp., Syllis amica, Syllis armillaris, Syllis gracilis, Syllis pseudoarmillaris, Syllis vittata, Parasphaerosyllis indica and Myrianida convoluta.     

Phylogeny and reproduction in Syllidae (Polychaeta)

The phylogeny of 12 representatives of the four syllid subfamilies is analysed using 44 morphological characters and 96 character states. The analysis is designed to answer two questions: are the four subfamilies monophyletic, and how are the different reproductive strategies related? Syllids show two modes of reproduction, epigamy and schizogamy. Epigamy is mainly constrained to two of the four subfamilies, Eusyllinae and Exogoninae but occurs also in some members of Autolytinae. Schizogamy can be of two types–scissiparity and gemmiparity–and both types are found in Syllinae and Autolytinae. Several modes of brood protection also occur in the family; in some epigamous species the eggs and even juveniles are attached to the main animal, whereas in brooding schizogamous species the stolons care for the young. Brood protection appears in Exogoninae, a few species of Eusyllinae, and some Autolytinae. The resulting tree indicates that members exhibiting brood protection are constrained to one clade, and that it is uncertain whether epigamy or schizogamy is the plesiomorphic reproductive mode. Three of the four subfamilies, Autolytinae, Exogoninae and Syllinae, are supported in the analysis whereas Eusyllinae is found to be polyphyletic.     

Endocrine control of reproductive periodicity in male Typosyllis prolifera (Polychaeta,Syllidae)

Under a “summer” light-temperature regime (LD 16:8, 20°C), the polychaete Typosyllis prolifera shows a spontaneous 30-day cycle of reproduction (stolonization). Previous experiments suggested cyclic reproduction to be controlled by corresponding changes in the inhibitory endocrine activity of the proventriculus. The evidence in this paper, however, indicates that the prostomium rather than the proventriculus is the primary source of control of reproductive periodicity. The prostomium of a “summer” male undergoes a spontaneous lunar cycle of hormonal activity. Hormone secretion occurs around day 13 after previous stolon release each time. The hormone probably operates a triggering mechanism that shifts worms from the postreproductive regeneration phase to the next stolonization phase. However, the action on peripheral targets may be indirectly via the proventricular system, the inhibitory activity of which probably becomes inactivated periodically under endocrine influence of the prostomium. Considering all the information available, a model of the cooperation of environmental factors and endocrine factors (prostomial and proventricular hormone) in the timing of the reproductive cycle in male T. prolifera is presented.     

Inter-population variability and character description in the sponge-associated Haplosyllis spongicola complex (Polychaeta: Syllidae)

Haplosyllis spongicola is probably the most representative symbiotic syllid harboured by sponges and has been widely reported from tropical, subtropical and temperate seas. Its external morphology seems to be very well adapted for its life-style, with all chaetae being simple and having two small teeth and a large main fang. However, the species has been the subject of a long-lasting taxonomic controversy, which gave rise to more than 15 synonymies, with hundreds of records worldwide. The present paper is based on the study of more than 28 populations obtained from around the world. These populations have been carefully analysed using different approaches (morphometry, morphology and biology). As a consequence, the existence of a pseudo-sibling species-complex within the so-called cosmopolitan H. spongicolahas been revealed. The most relevant characters (as well as their variability) that will allow a future identification of the species involved in the complex are fully described, illustrated and analysed.     

Giant pelagic larvae of Phyllodocidae (Polychaeta,Annelida)

The microscopic anatomy of giant pelagic larvae of Phyllodocidae was studied using routine histological, SEM, and TEM techniques. The larvae consist of two distinct regions: a large spherical trochophore measuring up to 2 mm in diameter and a posterior, long (up to 10 mm length), narrow rudiment of the adult body with up to 120 segments. The larvae have an unusual mixture of larval and adult features, including a very complex, well-developed brain and ganglia in the ventral nerve cord, and only a single pair of protonephridia located in the hyposphere of the trochophore. A muscular pharynx is not developed. The intestinal wall, especially in the trochophore region, consists of endodermal cells containing considerable nutritive material in the form of yolk-like globular inclusions. The digestive tract of all larvae was empty. The position of the frontal sensory organ and the prototroch, the structure of the parapodia and setae, and the three pairs of tentacular cirri dictate inclusion of the larvae in the family Phyllodocidae. The relatively enormous size and unusual pattern of development of the adult body may be adaptations for a long pelagic life and rapid settlement of the species, which inhabits slopes of islands and underwater mounts located far apart. J. Morphol. 238:93–107, 1998. © 1998 Wiley-Liss, Inc.     

Otostephanos (Rotifera,Bdelloidea, Habrotrochidae) with the description of two new species

Abstract

We present a morphological feature-based key for the genus Otostephanos and describe two new species, O. jolantae sp. nov. and O. ukrainicus sp. nov. For O. jolantae sp. nov. we analysed the intraspecific morphological variability and provided the barcodes of mtCOX1 mitochondrial gene. Further, we developed a method to standardize measurements for the Philodina type of corona and trophi measurements of bdelloids. Otostephanos jolantae sp. nov. is a large rotifer with a smooth cuticle and bright red-orange gut; it can be distinguished from the known species by a high triangular upper lip with a tongue-like tip not divided into lobes, spade-shaped swollen rump, and 6/6 dental formula. It is found in Sphagnum collected in Poland, Ukraine and the Czech Republic. Otostephanos ukrainicus sp. nov. has a long body covered with coarse-grained cuticle on the last two neck segments, trunk and rump; it is distinguished by long narrow head and neck, saccular-like swollen trunk, spade-like rump, and a tiny foot. Unlike the other species of this genus, it has band-like upper lip with two narrow, sharp protrusions separated by an interspace, unusually small spurs and trophi with 5/5 major teeth. Thus far, it is only found in Ukraine, in pine and oak forest litter. http://zoobank.org/urn:lsid:zoobank.org:pub:9FC484E3-67F5-43A9-8478-A7BE14FBE5E33     

A new species of Nicon Kinberg, 1866 (Polychaeta,Nereididae) from Ecuador,Eastern Pacific,with a?key?to?all known?species?of the genus

A new species of Nicon Kinberg, 1866 from the east Pacific coast of Ecuador is described. The new species is characterized by a long, thin dorsal ligule on median and posterior parapodia and infracicular sesquigomph falcigers in the neuropodia. A key to all species of Nicon is provided.     

Reproduction and larval development of Polydora robi (Polychaeta: Spionidae), an obligate commensal of hermit crabs from the Philippines

Abstract. The reproduction of a recently described spionid polychaete, Polydora robi , is examined from the Philippines. Adults inhabit a burrow in the apex of gastropod shells occupied by hermit crabs. Females were found to deposit broods of 18–94 egg capsules in the summer (June–August) and winter months (January–March) sampled. Paired or single egg capsules are attached by stalks to the inside wall of the burrow and contain 40–106 eggs which average 97 μm in diameter. The total number of eggs per brood ranges from 941–8761 eggs and is positively correlated with the total number of segments and length of female worms. Adults of P. robi are polytelic, producing ≤9 successive broods over a 3-month period; a mean of 6.7 d was exhibited between broods in the laboratory. Females utilize sperm stored in the seminal receptacles during successive spawnings. Development occurs within egg capsules until the 3-segment stage, at which time the planktotrophic larvae are released. Juveniles of ∼20 segments are competent to settle on gastropod shells inhabited by hermit crabs. Members of P. robi are relatively fecund, semicontinuous breeders; the life-cycle in this species is similar to the only other known obligate polydorid commensal of hermit crabs.     

On Antarctoscyphus (Cnidaria, Hydrozoa), a new genus of antarctic hydroids and the description of two new species

A new genus of the hydroid family Sertulariidae is established. Several species formerly assigned to the genus Symplectoscyphus Marktanner-Turneretscher, 1890 are included. A review of those species is given, including their main features along with some remarks. Two species new to science are added; the material of those species was collected in the Scotia Sea by the Spanish Antarctic Expedition “Antártida 8611”. Present autecological data are discussed.     

Two new species of gorgonian octocorals from the Tropical Eastern Pacific Biogeographic Region (Cnidaria,Anthozoa, Gorgoniidae)

The gorgoniid Eugorgia is exclusively an eastern Pacific genus. It has a wide geographic and bathymetric range of distribution, found from California to Perú and extends down to 65 m deep. Two new species are herein described. The morphological characters were analyzed and illustrated by light and scanning electron microscopy. Eugorgia beebei sp. n. can be distinguished by its white, ascending, sparse colony growth. Eugorgia mutabilis sp. n. can be distinguished by its white colony that changes color after collection, and the conspicuous sharp-crested disc sclerites. From a morphological point of view the new species are related to the daniana-group, the rubens-group and the siedenburgae-group of Eugorgia; their affiliations, and the proposal of a new group are discussed. These new species increases the number of species in the genus to 15, and contribute to the knowledge of the eastern Pacific octocoral biodiversity.     

A new species of Perinereis (Polychaeta,Nereididae) from Florida,USA, with a key to all Perinereis from the?American continent

Specimens belonging to a new species of Perinereis Kinberg, 1865 were collected fromnatural oyster reefs in an estuarine environmenton Florida’s southwest coast. The genus Perinereis includes more than 70 species, of which, Perinereis aibuhitensis (Grube, 1878), Perinereis brevicirrata (Treadwell, 1920), Perinereis camiguinoides (Augener, 1922), Perinereis jascooki Gibbs, 1972, Perinereis kuwaitensis Mohammad, 1970, Perinereis singaporiensis (Grube, 1878), Perinereis vancaurica (Ehlers, 1868) and the new species have two short bars on Area VI and notopodial dorsal ligules that are not greatly expanded. The most geographically close species is Perinereis brevicirrata. The new species can be distinguished from Perinereis brevicirrata by the absence of a notopodial prechaetal lobe, Area V with 3 cones in a triangle, and Area VII-VIII with two well-defined rows of 33 paragnaths, the basal row having longer paragnaths in relation to the distal ones. The new species resembles Perinereis singaporiensis based on the absence of notopodial prechaetal lobe; however, the two species differ in some morphological characteristics such as tentacular cirri length, shape of dorsal notopodial ligules, and falciger blades. A key to all American species of Perinereis is included.     

A new genus and species of the Syllidae (Annelida, Polychaeta) from south India

A syllid species new to science is described from intertidal sandy sediments on the cast coast of India, for which a new genus is erected: Psammosyllis aliceae gen. et sp.n. Incorporation into either the Eusyllinae or the Exogoninae is unresolved, because it possesses characters of both of these poorly defined subfamilies.     

Fine structure of the spermatozoon of <Emphasis Type="Italic">Diopatra neapolitana</Emphasis> (Polychaeta,Onuphidae)

The identification of Diopatra species lacks of clear diagnostic features of taxonomic importance and the knowledge of their reproductive characters is scant. The spermatozoa of Diopatra neapolitana were ultrastructurally investigated by electron microscopy in order to correlate the mode of reproduction with sperm cells morphology. The mature male gamete has a depressed subspherical nucleus, a cone-like acrosome, and a long flagellum. The acrosome is conical in shape and radially symmetrical, with a base diameter twice the height. Within the acrosome vesicle, the basal region includes a very electron-dense thickened ring composed of paracrystalline substances. The subacrosomal space is filled with a poorly electron-dense material, with straight filaments axially arranged to form a perforatorium. The nucleus contains the complete axial canal, holding the hind perforatorium region. The middle piece consists of five mitochondria with well-distinct membranes and tubulo-vesicular cristae. Two centrioles are located perpendicularly to each other. The proximal one lies in the central fossa and the distal one, slightly eccentric to the sperm axis, anchors to the plasma membrane by nine satellite rays of the pericentriolar complex. The axoneme has a 9+2 arrangement of microtubules. In general, the spermatozoon of D. neapolitana conforms exteriorly to the typical ect-aquasperm; the acrosome complex ultrastructure, however, shows noticeable modifications from the basic form. This finding agrees with the previously observed reproductive pattern (broadcast spawning—free-swimming larvae) of D. neapolitana belonging to Santa Gilla population, and may be helpful to solve the taxonomic problems of the D. neapolitana complex as well.     

Distribution and diversity of the Syllidae (Annelida: Polychaeta) from the Mexican Gulf of Mexico and Caribbean

The objective of this study was to contribute to the knowledge of the syllids distributed in the eastern coasts of Mexico (Gulf of Mexico and Caribbean) taking into consideration their composition, distribution and diversity. Sampling was done at 77 stations including 49 in soft bottoms (terrigenous and carbonate sediments), and 28 in hard bottoms (coralline substrates) sampled in nine reef zones included in three reef systems (Veracruz, Campeche and Cozumel). In all 2084 individuals were collected (13.5% in soft sediments and 86.4% in coralline areas). Forty-five species were identified: 31 in soft bottoms and 38 in corals, with 21 species common to both types of environments. In soft bottoms, the highest species richness and diversity were found in the Carbonate Zone, while syllids were uncommon in the Terrigenous Zone. In hard bottoms, the highest density, species richness and diversity values were found in the Veracruz Reef System, followed by the Campeche Bank and Cozumel Island Reef Systems. The dominant species in soft bottoms were Haplosyllis spongicola, Exogone lourei, Typosyllis cornuta and T. papillosus, whereas T. alosae, T. corallicola, T. cornuta and H. spongicola dominated in hard bottoms. The importance and success of the syllids in both soft bottoms and reef environments, particularly in those of the Gulf of Mexico is emphasized.     

Unusual granules in the ejaculatory duct of a Microphthalmus species (Polychaeta,Annelida)

Summary The paired prominent ejaculatory ducts of the hermaphroditic polychaete Microphthalmus cf. listensis are surrounded by gland cells the processes of which penetrate the ducts themselves. These cells produce, in separate regions, two different types of spherical granules. Type I is composed of an electron dense and an electron lucent part. Type II granules contain a tubular filament that forms a single or double spiral in the periphery of a more or less unstructured electron dense material. Golgi vesicles give rise to this granule type. During the passage of sperm, these granules are obviously discharged into the lumen of the duct. Here they change form and probably dissolve. Their function is as yet unknown; capacitation of sperm is assumed.     

脊颜茎蜂属评述暨一新种(膜翅目:茎蜂科)

基于模式标本和新材料研究了茎蜂科脊颜茎蜂属,修订了该属属征和主要鉴别特征.该属唇基上区具锐利中脊,下唇须第4节短,明显宽于下颚须第4节,左上额粗短,中部显著弯折,雄虫多数鞭分节腹侧钝齿状突出,雌虫部分锯刃具多列亚基齿等特征,与茎蜂科其余各属均不相同.描述了脊颜茎蜂属1新种,采集自江西和湖南南部山区.编制了种检索表.     

New Spirorbidae (Polychaeta: Sedentaria) from the East Pacific, Adantic, Indian and Southern Oceans

Spirorbis bifurcatus, Spirorbis rothlisbergi, Spirorbis spatulatus, Pileolaria lateralis, Pileolaria marginals, Pileolaria spinifer, Pileolaria tiarata and Pileolaria potswaldi are described from California, Spirorbis strigatus from Madeira, Pileolaria dakarensis from W. Africa, Pileolaria (Duplicaria) zibrowii from Madagascar, Pileolaria alata and Pileolaria (Nidularia) nidica from Curacao, Pileolaria (Nidularia) palliata from S. Africa, Pileolaria (Jugaria) atlantica from north of the Azores, Romanchella bicava from Amsterdam Island, Romanchella pustulata from Chile and Helicosiphon platyspira from Marion Island. Of the new subgenera, Jugaria is proposed for forms having compound opercula (as in Pileolaria granulata L. and most Sinistrella species) and Nidularia for those with opercula that do not completely protect the embryos.
Some of the Californian forms have probably resulted from sympatric speciation in both the genera concerned. The morphology and zoogeography of spirorbids suggest division into the subfamilies Spirorbinae, Circeinae, Pileolariinae, Januinae, Romanchellinae and Paralaeospirinae.