Polydora and related genera (Polychaeta: Spionidae) from the Grand Caribbean region

The study of previously unidentified material of Spionidae from the Grand Caribbean region resulted in the discovery of five new species in four genera: Boccardia salazari sp. nov., Dipolydora anatentaculata sp. nov., D. contoyensis sp. nov., Polydora quintanarooensis sp. nov. and Pseudopolydora floridensis sp. nov. Boccardia salazari is characterized by two types of major spine in chaetiger 5, one with expanded end bearing cusps without bristles, the other, simple, falcate; D. anatentaculata is characterized by an occipital antenna, and major spines simple, falcate, without subterminal protuberance; D. contoyensis is characterized by six pairs of branchiae on chaetigers 11–16, major spines with two large accessory teeth on concave and convex sides in chaetiger 5, and pygidium small, glandular, cuff‐shaped with dorsal notch; Polydora quintanarooensis is characterized by two eyes, modified spines of chaetiger 5 falcate, with a lateral tooth, and gizzard‐like structure present at segment 16, and Pseudopolydora floridensis is characterized by two types of major spines in chaetiger 5, first falcate, second pennoned, with both types arranged in U‐shaped, double row, a caruncle extending to chaetigers 6–7, and an occipital antenna. A key to all species of Boccardia, Dipolydora, Polydora and Pseudopolydora from the Grand Caribbean region is provided.     

Morphology and natural history of the cryptogenic sponge associate Polydora colonia Moore, 1907 (Polychaeta: Spionidae)

The polychaete Polydora colonia is a widely distributed symbiont of sponges that has been reported as introduced into the Mediterranean Sea. Polydora colonia is re-described based on specimens associated with the sponges Microciona prolifera and Halichondria bowerbanki from New York and aspects of its reproduction and feeding biology are described for the first time. The morphology of P. colonia agrees with previous reports of this species. Females of P. colonia deposited egg capsules (14–19 eggs/capsule) in their tubes on sponges and adelphophagy was observed. Larvae appear to be competent to settle on hosts at the 13-chaetiger stage. One commensal ciliate and one parasitic copepod were found associated with P. colonia. P. colonia as an introduced species is evaluated based on current evidence. Sponge material was observed in the gut of > 50% of the worms examined but further studies are needed to evaluate whether P. colonia is selectively feeding on M. prolifera.     

Review of the types of Palola (Eunicidae: Polychaeta)

As part of a review of the types of all currently known species of eunicid poly-chaetes, the genus Palola is reviewed. Nineteen named taxa are here accounted for; of these 12 are tentatively considered valid; the other species are incompletely known, or are considered synonyms of other species or are indeterminable. The number of species suggested in this paper may change once variability and allometric patterns have become better understood.     

Revision of three species of Terebellides (Polychaeta: Trichobranchidae) described by C. Hessle in 1917 from the Southern Ocean

A revision of the taxonomic status of Terebellides antarcticus Hessle, 1917 Hessle, C. 1917. Zur Kenntnis der terebellomorphen Polychaeten.. Zoologiska bidrag frän Uppsala, 5: 39–258.  [Google Scholar], Terebellides longicaudatus Hessle, 1917 Hessle, C. 1917. Zur Kenntnis der terebellomorphen Polychaeten.. Zoologiska bidrag frän Uppsala, 5: 39–258.  [Google Scholar] and Terebellides minutus Hessle, 1917 Hessle, C. 1917. Zur Kenntnis der terebellomorphen Polychaeten.. Zoologiska bidrag frän Uppsala, 5: 39–258.  [Google Scholar] was undertaken through the examination of the type material. Thus, T. longicaudatus is regarded as a valid species and redescribed and T. antarcticus and T. minutus are considered as junior synonyms of Terebellides kerguelensis McIntosh, 1818. Terebellides longicaudatus is characterized by the presence of large lateral lobes on chaetigers 1 to 5, 1 and 2 being the largest, first thoracic acicular neurochaetae gently bent, wide thoracic neuropodia fascicles with numerous uncini and the first notopodium greatly reduced. Comments on several body characters related to branchial and chaetal structure are also provided.     

Reproduction and morphology of Polydorella (Polychaeta: Spionidae), including the description of a new species from the Philippines

A new spionid polychaete, Polydorella kamakamai, associated with sponges is described from the Philippines. Polydorella kamakamai is characterized by acicular neurosetae in segments 2–7, a fifth segment containing a ventral row of spines with digitiform bosses, and lack of branchiae. As in all members of the genus, P. kamakamai undergoes asexual reproduction via paratomy; the process of paratomy is examined through scanning electron and light microscopy. This species exhibits a growth zone following segment 10, leading to the production of stolon individuals budding from the stock individual; five or more individuals can thus be formed in a single chain. Paratomic division typically occurs in chains containing four to five individuals and as a result colonies are dominated by chains of two individuals. Sexual reproduction is documented for only the second time in the genus; P. kamakamai produces eggs in segments 13–15. Asexual reproduction and fine morphological structure of the ventral spines of the fifth segment are examined by SEM in P. dawydoffi and P. stolonifera. Polydorella dawydoffi is recorded for the first time from the Philippines and the Red Sea and these are compared to type specimens from Vietnam. The ventral spines of P. dawydoffi contain eight or nine rounded or pointed teeth along the apical end and a capillary extension not previously observed with light microscopy. Notes on feeding biology, parasitism by copepods, and a discussion of the evolutionary relationships of Polydorella and other polydorids are provided.     

The genus Lindaspio (Annelida: Polychaeta: Spionidae), and a new species from an oil field off Congo,western Africa

A new species of the genus Lindaspio (Polychaeta: Spionidae) is described from an oil field off Congo (tropical eastern Atlantic). Lindaspio sebastiena n. sp. is easily distinguished from the two other known species of Lindaspio, L. dibranchiata Blake and Maciolek (1992) and L. southwardorum Blake and Maciolek (1992), by the presence of a conical palp, the first noto-hooks beginning on setiger 55, the number of dorsal spines on setigers 2–4 and the absence of a caruncle. A new diagnosis of the genus is put forward, and the two spionid genera, Lindaspio and Scolecolepides, are discussed.     

The larval development of Argulus coregoni Thorell (Crustacea: Branchiura)

Summary

The larval development of Argulus coregoni from the first to the ninth stage was studied, with special reference to the morphological changes of the appendages and some other parts of the body.

A newly hatched larva is a copepodid-form measuring 0·6–0·7 mm long and approaches the shape of the adult after moulting into the second stage (0·7–0·9 mm). Throughout the larval stages, the first maxilla shows the most remarkable modification. The larvae of the first to the fifth stage are equipped with two strong, curved claws, which act as a clasping organ, at the terminal segment of the first maxilla. The basal segment expands considerably at the third stage (0·9–1·1 mm) prior to forming a sucker at the sixth stage (1·7–2·2 mm). The claws start to degenerate at the fifth stage (1·4–1·8 mm), but are still recognizable as a rudiment after the seventh stage (2·2–2·6 mm). The other distinct morphological changes that occurred are: (1) bifurcation of the anterior part of the dorsal ridges on the carapace, (2) development of the male accessory copulatory organ at the basal segments of the second to the fourth legs, (3) number of posteriorly directed minute spines on the ventral surface of the carapace, (4) number of elements in the supporting ribs of the suckers, (5) number of spines found at the first segment of the second maxilla, and (6) number of setae on the four pairs of thoracic legs.

The larval forms of A. coregoni younger than the fourth stage (1·1–1·4 mm) are indistinguishable from those of A. japonicus and A. foliaceus.     

Morphology and biology of a new Rhynchospio species (Annelida: Spionidae) from the South China Sea,Vietnam, with the review of Rhynchospio taxa

Adults of a new spionid polychaete, Rhynchospio nhatrangi, inhabit sandy tubes on muddy sand intertidal flats in an estuary of Nha Trang Bay, southern Vietnam. The worms are up to 8 mm long and 0.5 mm wide for 55 chaetigers. They are unique among spionids in the changes in the arrangement of hooks during ontogenesis: first development of tridentate hooks in neuropodia from chaetiger 10, later loss of hooks in chaetiger 10, and replacement of tridentate hooks by heavy unidentate hooks in neuropodia of chaetigers 11–14. Adults are simultaneous hermaphrodites having sperm in chaetigers 11–14 and oocytes from chaetiger 15 to 23–33. Spermatozoa are introsperm, about 300 µm long. Oocytes are about 120 µm in diameter, with a thin and smooth envelope. Fertilization and early larval development occur in a hatchery formed by elongated dorsal capillaries on the posterior chaetigers. Larvae escape from the hatchery probably when they have developed four chaetigers and then continue development in seawater, feeding on the plankton. When larvae have grown to 14–15 chaetigers, they likely undergo gradual metamorphosis and settle on the bottom. Metameric nuchal organs, glandular pouches in neuropodia, metanephridial segmental organs, hermaphroditism, sperm, and early larval morphology are described here for the first time for Rhynchospio species. An identification key is provided to eight currently recognized Rhynchospio species.     

Feeding habits of the endemic tropical parthenogenetic lizard Cnemidophorus nativo (Teiidae) in a restinga area of northeastern Brazil

The population of Cnemidophorus nativo in the restinga of Guaratiba, Bahia State, Brazil, is carnivorous with a diet consisting predominantly of insect larvae and termites, which is similar to that of other cnemidophorines. The absence of seasonal variation in diet may be a consequence of the availability of termites throughout the year. The small size of the termites and the ease with which both juveniles and adults eat larvae independent of their length were probably the cause of the poor relationship between lizard body measurements and mean number and volume of prey consumed.     

Larval development of Apiomithrax violaceus (A. Milne Edwards, 1868) (Decapoda: Brachyura: Majoidea: Pisidae) reared in laboratory conditions,and a review of larval characters of Pisidae

Apiomithrax violaceus (A. Milne Edwards, 1868 Milne Edwards A 1868 Observations sur la faune carcinologique des Iles du Cap-Vert Nouvelles Archives du Muséum d'Histoire Naturelle, 4, 49–68, pls 16–18  [Google Scholar]) is a pisid majoid crab occurring in tropical and subtropical coastal waters of the eastern and western South Atlantic. Larval development consists of two zoeal stages and a megalopa. Beginning with the first zoea, the duration of each larval stage at 24°C was 3–8 (5±1), 3–5 (4±0.5) and 9–15 (11±2) days, the megalopa and first crab instar appearing 9–11 (10±1) and 20–27 (23±2) days after hatching, respectively. Larval characters agree with those proposed for the Majoidea, in having nine or more setae on the scaphognathite in the first zoea and well-developed pleopods in the second zoea. However, larvae of A. violaceus do not fit larval pisid features. Zoeal stages differ from most other Pisidae in having lateral spines, a long rostral spine extending beyond the antenna, two spines per telson fork and a dorsolateral process on the third abdominal somite. The megalopa differs in having a spine dorsally on the carapace and on the basial segment of the second pereiopod. Two characters that are potentially unique to Apiomithrax include a zoeal antenna with an exopod that is much longer than the protopod, and a rostral spine that is longer than the dorsal spine. These characters should facilitate the identification of this taxon and could also be useful for phylogenetic studies. A review of larvae of 28 species among 14 genera indicated that there is no apparent single larval character that differentiates the Pisidae, with more limited phylogenetic analyses suggesting that this is a paraphyletic group. Apiomithrax, Eurynolambrus, Pisoides, Rochinia and Scyra have the most divergent morphological characters within the family. The analysis and inclusion of additional taxa is likely to shed more light on the sister-group relationships of the Pisidae. However, based on the extent of morphological interspecific variability of known larvae it is likely that the group, as presently defined by adult morphology, is not monophyletic.     

The larval development of Petalomera japonica (Henderson) (Decapoda,Dromiidae) reared in the laboratory

The complete larval development of Petalomera japonica (Henderson) is described, based on laboratory rearing. The species has two zoeal stages and a megalopa. Detailed comparisons are made with other dromiid larvae, particularly those of Petalomera wilsoni.     

Arabella aracaensis,a new species with growth rings on its mandibles,and some remarks on the endoparasitic Labrorostratus prolificus (Polychaeta: Oenonidae) from southeast Brazil

Two new species, Abaxisotima macrocaudata sp. nov. and Abaxisotima forcipiforma sp. nov., are described and illustrated, supplemental illustrations of several known species are provided. A key to species of the genus Abaxisotima Gorochov is presented. The type specimens are deposited in the Museum of Hebei University.     

The complete larval development of the crab Pilumnus spinifer (Brachyura: Xanthoidea: Pilumnidae) reared in the laboratory

The complete larval development of the crab Pilumnus spinifer from the western Mediterranean was obtained in the laboratory. All four zoeal stages and the megalopa are described and illustrated. The morphological characters of the larvae of Pilumnus spinifer are compared with those of other known larvae of the genus. The zoeae of P. spinifer show the rostral spine longer than the antennule (excluding aesthetascs); short lateral spines present on the carapace, and the mediolateral processes are present only in abdominal somites 2 and 3. The megalopa is similar to that of other Pilumnidae species. The morphology of the larval stages shows very similar characteristics to that of those of P. hirtellus and P. dasypodus, among the described stages of the family.     

Seven new species of Amynthas (Clitellata: Megascolecidae) and new earthworm records from Taiwan

Earthworm specimens collected in southern Taiwan consisted of seven new species of Amynthas and several previously known species, mostly widely distributed peregrines. The new species are A. nanrenensis of the octothecal A. corticis species group, A. monsoonus and A. huangi of the sexthecal A. aelianus species group, and four proandric octothecal species: A. chaishanensis, A. hengchunensis, A. kaopingensis and A. ailiaoensis. Amynthas chaishanensis has dorsal intrasegmental spermathecal pores, but the other three proandric species have dorsal, lateral or ventral intersegmental spermathecal pores, respectively. The proandric species are united by several features, including the enclosure of segment xi in a sac, as in A. formosae (also proandric), octothecal with spermathecae in vi–ix, spermathecal diverticula stalks generally kinked and often enclosed in membrane, and prostatic ducts divided polytomously into numerous small ductlets, which may be grouped into bundles of two to five. In A. ailiaoensis the prostatic duct trunk contains up to seven separate lumens in the ental half, surrounded by the circular muscle of the duct, while in A. chaishanensis the prostatic duct trunk contains about 40 small lumens. Of the previously known species in the collection, Pontodrilus litoralis and Metaphire houlleti are first reported from Taiwan. Additional locations for A. incongruus and A. robustus are given, and in the latter case the material appears to be the usual male‐sterile morph. Other species found are Pontoscolex corethrurus, Amynthas corticis, A. gracilis, Metaphire californica, and Polypheretima elongata.