Mandibular Palp Research Articles

The first record of the genus Vejdovskybathynella Serban and Leclerc, 1984 (Syncarida, Bathynellacea, Bathynellidae) in the Iberian Peninsula: three new species

Three new species of the genus Vejdovskybathynella are described from caves in northern Spain. It is the first time that this genus has been documented in the Iberian Peninsula. Vejdovskybathynella edelweiss n. sp. has several unique features: the setal formula of the antenna (0/2+exp/2+0/1+0/0+0/2+2/4); the form of the segments and claws of the mandibular palp of the mandible of the male; exopod of the female thoracopod VIII similar in size to the endopod (exopod is always longer than the endopod); small frontal projection of the basipod of the male thoracopod VIII, large or very large is common; the form and size of the lobes of the male thoracopod VIII is unique; the second spine of the furcal rami 2.5 times longer than the first spine. Vejdovskybathynella caroloi n. sp. has a unique male thoracopod VIII with a spur in the exopod that is a feature unknown in the genus, and additionally, this species has the smallest endopod of the thoracopod VIII male of the entire genus; the presence of three aesthetascs in segments VI and VII of the antennule had not been observed in this genus until now; the form of the segments of the mandibular palp of the mandible of the male are unique; the distal spine of the sympod of the uropod is larger than in other species, whereas in the rest of the species of the genus they are equal in size. Vejdovskybathynella pascalis n. sp. is the smallest species of the genus and has two and three aesthetascs in segments VI and VII of the antennule, respectively; it is the only species of the genus that has one seta on segment I and two setae on segment IV of the antenna; it has a unique male thoracopod VIII with a small spur on the frontal projection of the basipod and with the endopod larger than all other species in spite of its small size; the basal spine of the sympod of the uropod is smaller than the other three.

Larval development of Pandalus gracilis Stimpson (Crustacea: Decapoda: Pandalidae) reared in the laboratory

The complete larval development of Pandalus gracilis Stimpson is described based on larvae reared in the laboratory. The species has four larval stages (stages 1–4) and one postlarval stage (stage 5). The survival rate of the postlarva stage is very high. Of the 40 larvae reared individually, 39 larvae moulted to the postlarva stage within approximately 21 days at a rearing temperature of 15°C. Larval morphological characteristics of the species are described and figured. Larval development of P. gracilis is compared with other Pandalus and Pandalopsis species. Komai (1999) divided species of Pandalus into four species groups based on adult morphology. Pandalus gracilis belongs to the P. hypsinotus group. In this study, using larval characters, the P. hypsinotus group can be divided into two groups by the appearance of the mandibular palp and the shape of the telson: the first group contains P. hypsinotus and P. danae, and the second group contains P. gracilis, P. prensor, and P. nipponensis.

Ontogeny of feeding apparatus and foregut of mud crab Scylla serrata Forsskål larvae

The development of the feeding apparatus of the mud crab Scylla serrata larvae was studied using electron microscopy for mandibles and light microscopy for other paired mouthparts and the foregut. The six paired mouthparts, which consisted of the mandibles, maxillules, maxillae, first maxillipeds, second maxillipeds and third maxillipeds, were dissected from specimens representing each larval stage. The first five paired appendages were already present in newly hatched larvae while third maxillipeds appeared only at the megalopa stage. Mandibles displayed complex incisor and molar processes at early zoeal stages, which became simple in morphology at megalopa. Mandibular palp buds were observed at the zoea 5 stage and these became fully developed as three-segmented mandibular palps at the megalopa stage. Endopods of other paired mouthparts exhibited increased number of setae and size as the individual metamorphosed from zoeal stages to megalopa and crab instar. The foregut appeared as a continuous cavity at zoea 1 where the cardiopyloric valve was indistinct while the filter gland was clearly identifiable. Zoea 2 and succeeding zoeal stages exhibited a setose foregut; the gastric mill and its lateral and median teeth were prominent at zoea 3 stage. The significance of these morphological changes is discussed in terms of its implication in larval feeding management.

A new genus and species of Heteromysini (Crustacea‐Mysidacea) from the backwater of Kochi (Kerala, India)

Kochimysis pillaii, a new genus and species of Heteromysini collected from the backwater of Kochi, is described. The new genus is closely related to the genus Deltamysis but is distinguishable from the latter by the following characters: antennules of male have a small setiferous lobe; antennal scale is without distal suture; second segment of mandibular palp broad; endopodite segments of maxilla subequal in length; in male carpus and propodus of second thoracic endopod with notches on outer margin; outer pair of apical spines on telson longer than the inner pair.

Complete larval development of the hermit crabs Clibanarius aequabilis and Clibanarius erythropus (Decapoda: Anomura: Diogenidae), under laboratory conditions, with a revision of the larval features of genus Clibanarius

The complete larval development (four zoeae and one megalopa) of Clibanarius aequabilis and C. erythropus, reared under laboratory conditions, is described and illustrated. The larval stages of the two northeastern Atlantic Clibanarius species cannot be easily differentiated. Their morphological characters are compared with those of other known Clibanarius larvae. The genus Clibanarius is very homogeneous with respect to larval characters. All Clibanarius zoeae display a broad and blunt rostrum, smooth abdominal segments and an antennal scale without a terminal spine. Beyond the second zoeal stage, the fourth telson process is present as a fused spine, and the uropods are biramous. In the fourth larval stage all species display a mandibular palp. The Clibanarius megalopa presents weakly developed or no ocular scales, symmetrical chelipeds, apically curved corneous dactylus in the second and third pereiopods, and 5–11 setae on the posterior margin of the telson. Apart from the number of zoeal stages, Clibanarius species may be separated, beyond the second zoeal stage, by the telson formula and the morphology of the fourth telson process.

Two new sphyrapodid species (Crustacea: Tanaidacea: Apseudomorpha) from southwestern Japan

Two new species, Kudinopasternakia balanorostrata and Pseudosphyrapus quintolongus are described from Japan. Kudinopasternakia balanorostrata is characterized by an acorn-shaped rostrum. It most closely resembles K. siegi (Viskup & Heard, 1989), but can be distinguished by the shape of the rostrum, the number of setae on article 2 of the mandibular palp, and the setation on the outer lobe of the fixed endite of the maxilla. Pseudosphyrapus quintolongus is characterized by an unusually large lateral process on pleonite 5, which distinguishes it from all other species in the genus. Keys to species of Kudinopasternakia and Pseudosphyrapus are given.

Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae) um parasito da cavidade bucal do peixe marinho, Oligoplites saurus (Bloch & Schneider) (Osteichthyes, Carangidae) do Estado do Rio Grande do Norte, Brasil

Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae) a buccal cavity parasite of the marine fish, Oligoplites saurus, is described on the basis of eight male specimens and one female. The fish hosts were captured in the coastal waters of Natal, Rio Grande do Norte State, Brazil. In the new species, the anterior margin of the cephalon is doubled ventrally over the bases of the antennae. In this respect, it resembles C. recifea Thatcher & Fonseca, 2005. It differs from that species, however, in being much smaller and having basal carinae on the pereopods 4 to 7 that are small and rounded (not large and pointed). Also, pleopods 2-4 lack the folds and pockets that are present in C. recifea . The new species can be distinguished from all known Cymothoa spp. by the mandibular palps which are entirely covered with small spines in adult males. The mancas of the new species resemble those of Cymothoa oestrum since they have elongate antennae but they are wider and have shorter uropods.

Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae) a buccal cavity parasite of the marine fish, Oligoplites saurus (Bloch & Schneider) (Osteichthyes, Carangidae) of Rio Grande do Norte State, Brazil

Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae) a buccal cavity parasite of the marine fish, Oligoplites saurus, is described on the basis of eight male specimens and one female. The fish hosts were captured in the coastal waters of Natal, Rio Grande do Norte State, Brazil. In the new species, the anterior margin of the cephalon is doubled ventrally over the bases of the antennae. In this respect, it resembles C. recifea Thatcher & Fonseca, 2005. It differs from that species, however, in being much smaller and having basal carinae on the pereopods 4 to 7 that are small and rounded (not large and pointed). Also, pleopods 2-4 lack the folds and pockets that are present in C. recifea. The new species can be distinguished from all known Cymothoa spp. by the mandibular palps which are entirely covered with small spines in adult males. The mancas of the new species resemble those of Cymothoa oestrum since they have elongate antennae but they are wider and have shorter uropods.

A new species of Cletocamptus (Copepoda: Harpacticoida) from Chile and some notes on Cletocamptus axi Mielke, 2000

Some specimens of Cletocamptus were found in Salar de Surire (Chilean Andean plateau) during two sampling trips in October 2004 and October 2005. Although the Chilean material was preliminarily identified as C. axi, after careful inspection, it was clearly a new Chilean Cletocamptus species, C. cecsurirensis. The new species was found to be similar to C. levis, C. sinaloensis, C. fourchensis, C. deborahdexterae, and C. axi in the combination of the armature formula of the mandibular palp, shape of the lateral spinulose element of the maxillulary arthrite, and armature formula of P1–P4. Cletocamptus cecsurirensis and C. levis can be distinguished from C. sinaloensis, C. fourchensis, and C. deborahdexterae by the P1 EXP:ENP length ratio. Cletocamptus cecsurirensis and C. levis can be separated by the P5 baseoendopod:EXP length ratio. Cletocamptus cecsurirensis shows the sexual dimorphism typical for the genus. The new species also shows sexual dimorphism in the rostrum, similar to that found for C. retrogressus, C. albuquerquensis, and C. levis. A complete description of the new Chilean species and some amendments to the original description of C. axi are given.

New apseudomorph tanaidaceans (Crustacea: Peracarida: Tanaidacea) from eastern Australia: Apseudidae, Whiteleggiidae, Metapseudidae and Pagurapseudidae

B lazewicz-Paszkowycz, M., and Bamber, R. N. 2007 New apseudomorph tanaidaceans (Crustacea: Peracarida: Tanaidacea) from eastern Australia: Apseudidae, Whiteleggiidae, Metapseudidae and Pagurapseudidae. Memoirs of Museum Victoria 64: 107–148. Investigation of apseudomorph tanaidacean material collected between 1979 and 1984 from Bass Strait and held in the collections of Museum Victoria, Melbourne, Australia, has revealed eight new species, fi ve in Apseudidae (including one new genus), two in Metapseudidae (including one new genus) and one in Pagurapseudidae. These taxa are described below. The new apseudid genus Annexos shows great similarity to Apseudes sensu stricto, but is without an exopod on the cheliped or on pereopod 1. Two new species of Apseudes show a common feature of maxilliped spination in eastern Australian taxa; Spinosapseudes colobus sp. nov., the second species of this genus, is described from a similar geography to the fi rst, but is distinguished by the proportionately more compact articles of the antennular and antennal peduncles, the mandibular palp and the pereopods. Pugiodactylus syntomos sp. nov. is predominantly distinguished by having compact articles in the antenna, cheliped and pereopod 1; Labraxeudes heliodiscus gen. et sp. nov. (Metapseudidae) has a unique combination of substantial rostrum, exopodites on the cheliped and pereopod 1, compact antenna, short uropod, simple pereonite setation, compact propodi, dorsum of pereopod 1 basis without apophyses, robust cheliped and antennule peduncle without inner row of conspicuous denticulation; Metapseudes wilsoni sp. nov., only the second species of this genus to be discovered, is distinguished by its conspicuously more slender antennules and antennae with more pronounced, pointed denticulations on the proximal antennule peduncle article, and one fewer article in the main fl agellum of the antennule; Similipedia diarris sp. nov., again the second species of this genus to be discovered, is distinguished by having no squama on the antenna, no rostrum, and dorsal spiniform apophyses rather than setae on the pereonites.

Swimming and cleaning in the free‐swimming phase of Argulus larvae (crustacea, branchiura)—Appendage adaptation and functional morphology

The free-swimming early larval stages of Argulus foliaceus (Linneaus) (Branchiura) are studied using digital video, light microscopy, and SEM. We analyze and document the mode of swimming in the hatching stage of A. foliaceus and the subsequent juvenile stages with fully developed thoracopods. We present new observations and an analysis of the functional morphology of a cleaning behavior in the first stage. This stage swims very efficiently using the large exopods of the second antennae in concert with the mandibular palp (naupliar limbs), while the subsequent stages use the now developed thoracopods for propulsion. This posterior shift in propulsion is similar to--but independent from--what is seen in other crustaceans. The hatching stage has previously been referred as a "metanauplius" but as the first and second maxillae are developed and active, and buds of all four thoracopods are present, it is too advanced to be included in the naupliar phase. The hooks of the first antennae and the distal hooks of the maxillae are demonstrated to function not only as attachment organs (to the host), but also to play a significant role in the cleaning of the naupliar swimming appendages. A digital video-based analysis of the swimming mode is provided. The larval swimming pattern is generally similar to that of other crustaceans such as Branchiopoda and Cirripedia, but autapomorphies of the Branchiura include the following: 1) While actively swimming, the naupliar appendages are almost straight during the recovery stroke and 2) they have a relatively small deflection during movement ( approximately 25 degrees or approximately 35 degrees for mandible and second antenna respectively), 3) the larval mandible has a uniramous palp which is the retained exopod. The morphological implications of the transition from the possibly nonfeeding pelagic, or free-swimming, first larval stage to the feeding, parasitic second stage are discussed and compared with other crustaceans.

Two new species of the genus Heteropsyllus (Crustacea, Copepoda, Harpacticoida) from Jeju Island, Korea and Devon, England

During a study of the harpacticoid copepods from off Jeju Island, in the South Sea of Korea, a new species of the genus Heteropsyllus was discovered. Heteropsyllus coreanus sp. nov. differs from its congeners in the following combination of characters: a pointed apex of rostrum; areolated ornamentation of the cephalothorax; a single basal seta on the maxillule and the shape of the fifth thoracopod in the female. This is the first record of the genus Heteropsyllus from Asia. The second new species is described from specimens in the Norman collection in the Natural History Museum, London (NHM). Heteropsyllus celticus sp. nov. was originally identified as H. curticaudatus by Norman, however this new species is distinguishable from H. curticaudatus T. Scott (1894) by having reticulated ornamentation on the cephalothorax, a strong seta on the proximal endite of the maxilla, only one seta on the exopod of the mandibular palp, and a different armature formula of the swimming legs. This study reveals that the mouthpart structures of Heteropsyllus can be important in identifying the species of this genus, and should be re‐examined in all other species of Heteropsyllus.

Transkalliapseudes spinulata, new genus, new species (Crustacea: Tanaidacea: Kalliapseudidae) from the northwest Australian shelf

A new kalliapseudid genus, Transkalliapseudes is erected to receive T. spinulata, n. sp. The description of the new genus and species are based on two males collected at depths of 44–82 m from the Northwest Continental Shelf of Australia. Transkalliapseudes n. gen. shares most features (setation of uniarticulate mandibular palp, cheliped, and dactylus of pereopod I) with those of the subfamily Kalliapseudinae; however, the dactylus on pereopods IV–VI are similar to those found in the subfamily Hemikalliapseudinae, as well as, some species of Kalliapseudes. The presence of numerous granular-like spinules on appendages of T. spinulata appears to be a unique character. A key and table for the separation of the genera within the subfamily Kalliapseudinae is presented.

Mysidacea (Crustacea) from the Minicoy lagoon (Lakshadweep, India) with description of a new species of Anisomysis

Four species of mysids collected from the Minicoy lagoon are reported. Anisomysis minicoyensis sp. nov. is distinguished from the related species by the shape of the rostrum, the relative length of the antennal scale and the short protuberances on the second segment of the mandibular palp. The other three species recorded are Siriella australiensis, Anisomysis truncata and unidentified species of subfamily Gastrosaccinae.

A new epacteriscid copepod (Calanoida: Epacteriscidae) from the Yucatan Peninsula, Mexico, with comments on the biogeography of the family

ABSTRACT The calanoid copepod family Epacteriscidae is represented by species from tropical marine and anchialine environments. Surveys of the anchialine invertebrate fauna of the Yucatan Peninsula, Mexico, have resulted in a number of interesting records of crustaceans during the last decade, but no records of Epacteriscidae. However, recent collections from hypogean environments of the Yucatan have yielded specimens of a new species of the previously monotypic genus Balinella. The specimens were included in this genus by having three outer spines on the third exopodal segment of legs 3 and 4, a biramous mandibular palp, and an antennal endopod longer than the exopod, among other characters. The new species, B. yucatanensis, is described on the basis of male and female specimens collected in caves associated with three different karstic sinkholes. The new species is distinguished from its only known congener, B. ornata Fosshagen, Boxshall and Iliffe, 2001, by the strong asymmetry of the caudal rami in fe...

Evolution of Afrotropical freshwater crab lineages obscured by morphological convergence

We use sequence data derived from six DNA gene loci to examine evolutionary and biogeographic affinities among all freshwater crab families. With an emphasis on the Afrotropical fauna that includes Africa, Madagascar, and the Seychelles, we test the proposed Gondwanan cladogenesis of the group. Phylogenetic results demonstrate that contemporary distribution patterns of freshwater crab lineages are incongruent with the expected area cladogram of continental fragmentation. Instead, our phylogenetic estimate and divergence time estimation indicate a post-Gondwanan, early Cretaceous cladogenesis for freshwater crabs implying that the acquisition of a freshwater lifestyle was achieved more recently. A dispersal hypothesis as opposed to vicariance appears to best explain the contemporary distribution pattern of this group. However, our results do not explicitly disprove a Gondwanan origin for the Afrotropical freshwater crabs. Alarmingly, these results suggest that most of the currently recognized freshwater crab families are unreliable taxonomic groupings since virtually no Afrotropical freshwater crab families formed monophyletic units thus obscuring inferred biogeographic relationships. Convergence in characters associated with the terminal segment of the mandibular palp is clearly a pervasive obstacle in the taxonomy of this group.

Apolethon Hippoperus (Copepoda: Harpacticoida): A New Species from Southeastern Alaska

Abstract A new harpacticoid copepod species of Apolethon (Laophontidae) from the intertidal zone of a subarctic bay in southeastern Alaska is described and illustrated. Apolethon hippoperus n. sp. is distinguished from its three congeners (A. fumator, A. trigonus, A. bilobatus) by paired pleural glands on the third urosomite. Adult Apolethon hippoperus bear conspicuous ovoid mucin structures located laterally on the double genital somite, originating from the pleural glands. Based on the description of A. hippoperus generic affinities become problematic. An examination of the apomorphies (P1 morphology, type of sexual dimorphism of male P3, P2-P4 with 2-segmented endopods; setation on A2 exopod, maxillular arthrites and basis, setation of mandibular palp) defining the Laophontoidea sensu Huys 1990 suggests that Apolethon is a laophontoidean but not a laophontid. Currently, we cannot place Apolethon with certainty in any known family of the Laophontoidea and recommend that Apolethon is placed as genus ince...

A New Species of the Genus Attheyella (Copepoda: Harpacticoida: Canthocamptidae) from Gosu Cave in Korea

A new species, Attheyella namkungi sp. nov., is described from Gosu cave at Danyang, Chungcheongbuk-do, South Korea. This species bears a superficial resemblance to A. coreana Miura, 1969 in having a 2-segmented mandibular palp with only four smooth apical setae, and in the armature formulae of the antennary exopod and thoracic legs. However the new species is clearly distinguishable by the non-sexually dimorphic caudal rami, two long plumose setae and a short seta on leg 6, and the absence of the setular row at the inner lateral margin of each caudal ramus. The new species is characterized from other congeners by having two adjacent inner spines on female leg 3 endopod-2, the caudal ramus twice as long as its width, absence of a barbed apophysis on male leg 3 endopod-2, and the seta number of legs 5 and 6. A key to the Korean species of the genus Attheyella is provided.

On the genus Typhlocypris Vejdovský, 1882 (Crustacea: Ostracoda: Candoninae), with description of two new species

In the present paperthe genus Typhlocypris Vejdovský, 1882 is divided into two subgenera: Typhlocypris Vejdovský, 1882 and Pseudocandona Kaufmann, 1900. This division is made on the following characteristics: the morphology of the male antenna; the number of setae in the group on the second segment of the mandibular palp; and the morphology of the third thoracopod. The nominate subgenus is further divided into the following four species‐groups: eremita, caribbeana, rostrata and prespica. The formerzschokkei‐group is incorporated into the eremita‐group, which now has a total often Recent species and includes Typhlocypris (T.) pescei sp. nov. and T. (T.) skadari sp. nov., both described in the present paper. The new species were collected in subterranean waters of Greece and Montenegro respectively. Typhlocypris (T.) illiesi (McKenzie, 1971) is assigned to the eremita‐group and some additional description of this species is provided following examination of its type material. Pseudocandona serbani Danielopol, 1978 and Candona szoecsi Farkas, 1958 are synonymized with Typhlocypris (T.) eremita, the first one after rechecking its type material and the second one after finding a great variability in some populations. Fourteen species are added to the caribbeana‐group, which now includes 18 Recent species. One of its representatives, Typhlocypris (T.) cf. geratsi (Broodbakker, 1983), is recorded for the first time in Australia and a detailed description of the female is given. Typhlocypris (T.) marimotoi (McKenzie, 1972) is assigned to the rostrata‐group and some additional details of its morphology are given here after rechecking its type material. The rostrata‐group now has six Recent species. Typhlocypris (T.) prespica (Petkovski, 1959) remains the only representative of the prespica‐group. The subgenus Pseudocandona has six Recent species, all previously belonging to the compressa‐group. Males of T. (Pseudocandona) albicans (Brady, 1864), only rarely recorded by previous authors, were collected in Greece and are described in this paper. The same species is reported from Australia and Candona inexpecta Chapman, 1963, described from New Zealand, is synonymized with T. (P.) albicans after rechecking its type material. The present paper further contains a key to the subgenus Pseudocandona and all, except caribbeana, groups of the nominal genus. The taxonomy and zoogeography of the genus and its relation to the other Candoninae genera are also discussed.

New species of Cletocamptus and a new and fully illustrated record of C. sinaloensis (Copepoda: Harpacticoida) from Brazil

Two new species of harpacticoid copepods, Cletocamptus levis sp. nov. and Cletocamptus nudus sp. nov. are described from Brazil. Cletocamptus nudus sp. nov. seems to be closely related to C. schmidti based on the armature formula of mouth parts, P3 and P4, but can be separated based on the ornamentation of the anal operculum, relative length of exopodal and baseoendopodal setae of the female P5, and length ratio of the female P1 EXP:ENP. Cletocamptus levis sp. nov. seems to be more closely related to C. axi by the combination of a P1 ENP shorter than the P1 EXP, the armature formula of the mandibular palp, length: width ratio of caudal rami, and relative length of the female P3 ENP 2, male P2–P4 EXP 1, and number of segments of the male P3 ENP. It can be separated by the spinule ornamentation on the anal operculum, shape of female rostrum, relative length of outer spinules of female P2–P4 EXP, relative length of the setae on the male P5 EXP, armature of male P6, and by the dimorphic male rostrum of C. levis sp. nov. which is similar to that observed for C. retrogressus and C. albuquerquensis. Additionally, a fully illustrated record of the Mexican C. sinaloensis is reported for the first time from Brazilian waters, and C. affinis mongolicus Stěrba, 1968 is given full species status.