Robust Setae Research Articles

Discovery of Metacrangonyx in inland groundwaters of Oman (Amphipoda: Gammaridea: Metacrangonyctidae)

A new species of metacrangonyctid amphipod crustacean is described from the Salalah coastal plain aquifer in south-western Oman. This is the easternmost record of the group, with representatives previously thought to span from Hispaniola in the Caribbean to the Sinai Peninsula in Egypt. Metacrangonyx dhofarensis sp. nov. is unique among metacrangonyctids in the display of a sexually dimorphic armature on pereiopod IV. In addition, its hypertrophied coxal plate IV, reduced plates I-III, coxal plate VII lacking anteroventral lobe, and telson longer than broad are also distinctive. The same holds for the proximal segment of peduncle of antennule, provided with two hypertrophied robust setae on dorsolateral margin. The mandibles of the new species are devoid of palp, a feature shared only with Metacrangonyx antennatus Messouli, El Alami, Coineau & Boutin, 2008. The presence of metacrangonyctids on the coasts of the Arabian Peninsula is probably the result of a vicariant event rather than of an episode of trans-Arabian continental dispersal by a Middle East ancestor. This is in accord with the presumed marine origin of the family and with the existence of a shallow water marine continuum between the current south-western Omani coast and the peri-Mediterranean area -where most species of metacrangonyctids are located - until approximately 16 Ma.

Taxonomy and distribution of the genus Eurydice Leach, 1815 (Crustacea, Isopoda, Cirolanidae) from the Arabian region, including three new species

Three new subtidal species of Eurydice are described, i.e. Eurydice tridentata sp. nov. and Eurydice marisrubri sp. nov.from the Red Sea, and Eurydice marzouqui sp. nov. from the Arabian/Persian Gulf. These species can be separated fromall other Eurydice in the Arabian region by the absence of robust setae on the posterior margin of the pleotelson. E. maris-rubri has a truncate posterior margin bearing 5 apical teeth, E. marzouqui has a rounded pleotelson posterior margin with6 apical teeth and in E. tridentata the posterior margin is truncate, bearing 7 apical teeth, the central 3 prominent. Addi-tional information is provided for two previously described species: E. peraticis Jones, 1974 and E. arabica Jones, 1974.Previous records of E. inermis are attributed to E. tridentata and E. inermis is excluded from the region. A key is providedto separate all the Eurydice species likely to be found in the Arabian region. The distribution of all the Arabian Eurydice is described, and morphology is discussed in relation to habitat.

Siphonoecetini Just, 1983 (Crustacea, Amphipoda, Ischyroceridae) 9: New species in Rhinoecetes Just, 1983, Cephaloecetes gen. nov. and Neoecetes gen. nov. from the south-eastern Australian shelf

Six new species of Rhinoecetes Just, 1983, R. rhinoceros, R. dinoceros, R. brevirostris, R. coclearis, R. albomaculosus and R. meridianus, are described together with Cephaloecetes enigmaticus gen. nov., sp. nov. and Neoecetes conipes gen. nov., sp. nov. from eastern Australia from Moreton Bay in Queensland to Bass Strait and Tasmania. Cephaloecetes gen. nov. differs from Rhinoecetes by having the head front margin entire and a pseudorostrum arising underneath from thefrons. Neoecetes gen. nov. differs from Rhinoecetes in having two robust setae instead of one on the posterior projectionof gnathopod 2 carpus, a row of small accessory robust setae on pereopods 5 and 6 carpus instead of a single one, anduropod 3 ramus being conical instead of round. Keys to genera and species are given. A novel character, a pair of sternalpapillae, is documented in Rhinoecetes and Cephaloecetes on the ventral surface of pereonite 7 in adult females. The dis-tribution of the species is commented upon. The most diverse fauna of Siphonoecetini was found in Jervis Bay, New South Wales.

Siphonoecetini Just, 1983 (Crustacea, Amphipoda, Ischyroceridae) 9: New species in Rhinoecetes Just, 1983, Cephaloecetes gen. nov. and Neoecetes gen. nov. from the south-eastern Australian shelf

Six new species of Rhinoecetes Just, 1983, R. rhinoceros, R. dinoceros, R. brevirostris, R. coclearis, R. albomaculosus andR. meridianus, are described together with Cephaloecetes enigmaticus gen. nov., sp. nov. and Neoecetes conipes gen.nov., sp. nov. from eastern Australia from Moreton Bay in Queensland to Bass Strait and Tasmania. Cephaloecetes gen.nov. differs from Rhinoecetes by having the head front margin entire and a pseudorostrum arising underneath from thefrons. Neoecetes gen. nov. differs from Rhinoecetes in having two robust setae instead of one on the posterior projectionof gnathopod 2 carpus, a row of small accessory robust setae on pereopods 5 and 6 carpus instead of a single one, anduropod 3 ramus being conical instead of round. Keys to genera and species are given. A novel character, a pair of sternalpapillae, is documented in Rhinoecetes and Cephaloecetes on the ventral surface of pereonite 7 in adult females. The dis-tribution of the species is commented upon. The most diverse fauna of Siphonoecetini was found in Jervis Bay, New South Wales.

Two new species of the genus Chilibathynella Noodt, 1963 and Onychobathynella bifurcata gen. et sp. nov (Crustacea: Syncarida: Parabathynellidae) from New South Wales, Australia

Two new species of the parabathynellid genus Chilibathynella Noodt, 1963 are described from Australia. Chilibathynella joshuai sp. nov. has a unique combination of morphological characters, which includes five-segmented antenna, no epipodite on thoracopod I, two setae on the endopod of the male thoracopod VIII, homonomous row of 17 spines on uropodal sympod, uropodal exopod with four distal spines and a flat anal operculum. Chilibathynella digitus sp. nov. has two exclusive characters: six teeth on the pars incisiva of the mandible and a large, elongated digitiform protuberance (resembling a finger) on the basipod of male thoracopod VIII. The species also displays a unique combination of morphological characters, which includes five-segmented antenna, no epipodite on thoracopod I, no outer marginal seta on the first and second segments of the endopod of thoracopod I to VII, two setae on the endopod of the male thoracopod VIII, homonomous row of 12 spines on uropodal sympod, uropodal exopod with three distal spines and an unprotruded anal operculum. The two new species extend the distribution of the Chilibathynella genus in Australia from Victoria to New South Wales. A new genus and species of the family Parabathynellidae, Onychobathynella bifurcata gen. nov. sp. nov., is described from New South Wales, Australia. The new genus displays an evolutionary novelty, for Parabathynellidae and the entire group of Bathynellacea: the antennule, antenna, thoracopods, pleopod I and uropod have setae that are strong, thick, short, barbed and claw-like. This new genus is the first in the family without smooth setae on the antennule and antenna. The new genus also has a combination of characters that makes it unique in Parabathynellidae: the antennule is eight-segmented like Octobathynella Camacho and Hancock, 2010; the antenna is five-segmented; the labrum has 20 teeth; the exopod of thoracopod I to VII has only one segment; the endopod lacks dorsal setae on the first segment and the epipod is absent from thoracopod I; first pleopods are present and resemble two barbed curved claws; there are 18 bifid spines on the sympod, two spines and four setae resembling strong barbed claws on the endopod and six robust setae on the exopod of the uropod.

A new species of Acentrella Bengtsson (Ephemeroptera: Baetidae) from New York and New England (USA), redescription of the nymph of A. parvula (McDunnough), and key to known adult males of Nearctic Acentrella

A new species Acentrella rallatoma (type locality: Connetquot River, Oakdale, NY, USA) is described from nymphs and reared adults. Additional specimens were studied from southeastern New York, southeastern New Hampshire, coastal Connecticut, and Martha's Vineyard, MA, USA. Nymphs can be separated from those of other Nearctic species by: scraper-like outer incisors of mandibles, cerci alternately banded from bases to tips, and row of robust bristle-like setae (with modified tips) on dorsal edge of femora. Male imagos can be separated from those that lack hind wings by: distinctive colour pattern of abdominal terga, and genitalia with pigmented sclerotised penes cover. Comparative analysis of A. rallatoma with other Nearctic species revealed a lack of comparative data on nymphs of its presumptive sister species A. parvula. To facilitate future studies of this group, the nymph of A. parvula is redescribed and regional differences are discussed. Abdominal colour patterns of A. parvula that vary over its range from Florida, USA to Labrador, Canada are illustrated. Problems concerning genus-level diagnostic characters for Acentrella nymphs and adults are discussed to facilitate placement of future taxa. To complement existing keys to Nearctic nymphs of Acentrella a provisional key to the known adult males is given.

Two new species of cirolanid isopods (Crustacea: Isopoda: Cirolanidae) from Qeshm and Kish Islands in the Persian Gulf

Two new species of cirolanid isopods, Baharilana kiabii sp. nov. from the western coasts of Qeshm Island and Cirolana tarahomii sp. nov. from the northern cost of Kish Island and the western coasts of Qeshm Island in the Persian Gulf are described. Baharilana kiabii sp. nov. is characterized by pleonite 5 with a median projection and a pleotelson with two longitudinal, parallel ridges and small tubercles on the dorsal surface. Cirolana tarahomii sp. nov. is distinguished by a lateral margins of the frontal lamina converging slightly towards the base, the distal margin is extended with a narrowly rounded apex; appendix masculina distally acute with bifid apex, pleotelson with a broadly rounded apex and 8 marginal robust setae, uropodal rami not deeply bifid.

New record of Aegiochus spongiophila (Semper) (Isopoda: Aegidae), inhabiting the hexactinellid sponge Euplectella oweni Herklots & Marshall from off Makurazaki, southern Kyushu, Japan

The aegid isopod Aegiochus spongiophila (Semper, 1867) was recorded from Japanese waters for the first time. The specimens were collected from off Makurazaki, southern Kyushu, Japan, mainly inhabiting the cavity of the hexactinellid sponge Euplectella oweni Herklots & Marshall, 1868. One specimen of A. spongiophila was found in the gill cavity of the sea toad Chaunax abei Le Danois, 1978. Aegiochus spongiophila is characterized by 1) long antenna, reaching the posterior margin of pereonite 6, 2) pentagonal frontal lamina, 1.2 times as long as width, 3) inferodistal lobes produced on the carpus of pereopods 2 and 3, 4) long appendix masculina, 1.7 times as long as endopod of pleopod 2, 5) uropodal exopod narrower, 2.6 times as long as width, mesial and distal lateral margins with 6-8 and 10-12 robust setae, respectively, 6) produced caudomedial point, with 15-17 robust setae on the posterior margin of pleotelson.

First South American Phreatogammarid, with Comments on the Arrangement of Coxal and Sternal Gills, and on the Biramous Condition of the Seventh Pereiopod in Amphipods

Abstract Ruffia patagonica, a new genus and species of phreatogammarid amphipod, is described from a coastal cave on Madre de Dios Island (Chilean Patagonia). This is the first record of the family outside continental waters of New Zealand and New Caledonia. The new taxon displays some of the more distinctive features of the family, such as gnathopods with the palm margin lined with numerous unicuspid robust setae and with a denticulated inner margin of the dactylus; fifth pereiopod clearly smaller than pereiopod six and seven; “coxal gill” ( = exopod) absent from the seventh pereiopod; oostegites broadened; urosomites with posterodorsal robust setae; and third uropod equiramous with an elongated peduncle and with unsegmented cylindrical rami, the latter provided with numerous robust setae. In addition, the sternites of all pereionites, pleonites, and urosomites show a portion of integument delimited by hyaline frill that is presumably osmoregulatory in function, and is equivalent to the pair of sternal ...

Revalidation and redescription of Bungona illiesi (Lugo-Ortiz & McCafferty) (Ephemeroptera: Baetidae) from Australia, based on mitochondrial and morphological evidence

Bungona illiesi (Lugo-Ortiz & McCafferty) n.comb. was described from a single specimen collected in northern Queensland, Australia, as a species of Cloeodes Traver. The distinguishing characteristics of a minute maxillary palp, the absence of spination on the mandibles between the mola and prostheca, narrow-elongate gills, and medially expanded labial palps were later found to occur in Bungona narilla Harker, and the two species were synonymized. Extensive collecting in northern Queensland yielded larvae and adults of Bungona that differ from B. narilla in all life stages. We believe our specimens are equivalent to B. illiesi because they were collected only a few kilometres from the type locality, at least one specimen had both minute and normally sized maxillary palps, nearly all specimens had medially expanded labial palps, and the dorsal abdominal colour pattern was similar. Sequences of a 657-bp fragment of the mitochondrial gene cytochrome oxidase I supported the recognition of two species and confirmed the association of larvae and adults of B. illiesi. Interspecific p-distances ranged from 18.8–19.4% and the maximum intraspecific divergence observed was 1.7%. Based on the combination of morphological, mitochondrial, and biogeographical data, we show B. illiesi should be recognised as a valid species distinct from B. narilla. Larvae of B. illiesi differ from those of B. narilla by having fewer robust setae on the femora and a small lateral tooth on the outer incisor of both mandibles. Male and female adults differ from those of B. narilla by having less extensive red colouration on the abdominal terga.

Two new species of the genus Elasmopus Costa, 1853 (Amphipoda: Gammaridea: Maeridae) from off the Northeast Brazilian Coast

The genus Elasmopus has a worldwide distribution with most species living in warm waters. This work describes two new species, both from off the northeast Brazilian coast, including its oceanic banks of Fernando de Noronha Chain. The first new species, E. karamani sp. nov., is easily recognized by palm of gnathopod 2 with a medial concave portion, posterior margin of basis of pereopod 5 and 6 concave, epimeron 3 produced in a sharp spine, and the uropod 3 rami 2.4 times the peduncle length. The other one, E. lejeunei sp. nov., is very similar to E. balkomanus Thomas & Barnard, 1989 and E. lemaitrei Ortiz & Lalana, 1994 in having propodus of gnathopod 2 without palmar corner and posterior margin of basis of pereopod 5 concave. However, it differs from those by presenting gnathopod 2 with a weakly developed process near hinge of dactylus with some robust setae, followed by two tubercles. The propodus inner face presents one ridged line, about 1/3 of propodus length, and perpendicular lines of setae, from the proximal portion of the ridged line almost to the dactylus hinge. A key to all species of the genus Elasmopus recorded in the Brazilian coast is given.

Leipanthura casuarina, new genus and species of anthurid isopod from Australian coral reefs without a "five-petalled" tail (Isopoda, Cymothoida, Anthuroidea)

A new minute anthurid isopod, 2.7 mm long, is described. It is notable ina uropod with almost cylindrical terminal rami, lacking the typical anthuroid uropodal structure in which the flattened exopod is attached to the peduncle dorsolaterally and more proximal to the terminal endopod. The species has all the other features of Anthuroidea (cylindrical body, mandibular spine row absent or evident as lamina dentata, maxilla 2 fused with the lower lip as a hypopharynx) and many features of the family Anthuridae (paired statocysts, fused pleonites, compact mandible, pereopods 2 and 3 propodus with single palmar robust seta) and is placed in this family as a new genus and species, Leipanthura casuarina, close to Anthura, Exallanthura and Ptilanthura. Leipanthura casuarina is also unusual in lacking pereopod 7 in the adult.

A new genus and new species of Sphaeromatidae (Crustacea: Isopoda) from the Great Barrier Reef, Australia

Bruce, N. L. 2009. A new genus and new species of Sphaeromatidae (Crustacea: Isopoda) from the Great Barrier Reef, Australia. Memoirs of Museum Victoria 66: 35–42. Pooredoce garyi gen. nov., sp. nov., is described from Lizard Island, northern Great Barrier Reef, Australia. The genus is related to the group of sphaeromatid genera characterised by having long ‘fi nger-like’ extensions to the articles of the maxilliped palp, stout robust setae on the inferior margins of pereopods 1–3 and the uropodal endopod round in section, with the exopod about half as long as the endopod; similar genera are Cymodoce Leach, 1814 (Indo-Pacifi c species), Koremasphaera Bruce, 2003 and Oxinasphaera Bruce, 1997. Pooredoce gen. nov. is characterized by the adult male having a dorsally recessed dorsum to the pleotelson, the posterior margin of which has three enclosed foramens, two visible dorsally, the third visible only from the interior of the posterior margin, the two foramens are formed by the pleotelson posterolateral and median margin lobes coming into contact posteriorly; and the posterior margin of the pleon forms an irregular posteriorly directed ridge. Pooredoce garyi was collected from the reef crest and is known from the type locality, Lizard Island and at Hicks Reef.

Alicellidae and Valettiopsidae, two new callynophorate families (Crustacea: Amphipoda)

Two new families, the Alicellidae fam. nov. and the Valettiopsidae fam. nov., are described based on genera traditionally considered as lysianassoid amphipods. The Alicellidae fam. nov. are deep-sea scavengers often associated with thermal vents. They are distinguished from all other amphipods by a combination of characters which includes a callynophore on antenna 1; a broad, serrate left lacinia mobilis (occasionally narrow or vestigial) and a reduced or vestigial right lacinia mobilis (occasionally broad and serrate); simple or subchelate gnathopod 1; an elongate ischium, rectolinear carpus and propodus and a small dactylus on gnathopod 2 (not mitten-shaped); absence of apical robust setae on uropods 1 and 2 and a deeply cleft telson. The family contains 6 genera: Alicella Chevreux, 1899; Apotectonia Barnard & Ingram, 1990; Diatectonia Barnard & Ingram, 1990; Paralicella Chevreux, 1908; Tectovalopsis Barnard & Ingram, 1990; Transtectonia Barnard & Ingram, 1990. The Valettiopsidae fam. nov. are deep-sea scavenging amphipods defined by a combination of characters which includes a callynophore on antenna 1; serrate, curved incisors; a well developed, serrate lacinia mobilis on each mandible, an oblique setal row on the inner plate of maxilla 2, an elongate ischium on gnathopod 2; the absence of robust setae on the apices of uropods 1 and 2 and a deeply cleft telson. The family contains two genera, Valettiopsis Holmes, 1908 and Valettietta Lincoln & Thurston, 1983.

New species of Tridentella Richardson, 1905 (Isopoda: Cymothoida: Tridentellidae), tropical marine isopod crustaceans from the Banda Sea, Indonesia

Tridentella memikat sp. nov., Tridentella tanimbar sp. nov. and Tridentella brandtae sp. nov. are described and figured. T. memikat sp. nov. is the largest species in the family and can be identified by the broadly rounded pleotelson posterior margin, complete lack of dorsal ornamentation and antennule peduncle articles 2 and 3 each with the posterodistal angle produced. T. tanimbar sp. nov. is a sister species to T. recava Bowman, 1986, both species characterised by a flattened body shape, lack of dorsal ornamentation and deep excision to the pleotelson apex; T. tanimbar sp. nov. is identified by free lateral margins to pleonite 5, antennal flagellum extending to pereonite 5 or 6, pleon wider than pereon, the propodus of pereopods 1–3 lacking long slender robust setae, uropod exopod shorter (0.8) than endopod and the uropods not extending beyond the pleotelson. Tridentella brandtae sp. nov. is characterised by the posterior margin of the pleotelson being subtruncate and weakly emarginate; posterior margins of pereonites 6 and 7, pleonites 3–5 and the dorsal surface of the pleotelson weakly nodulose; inferior margins of the propodus of pereopods 2 and 3 with a double row of robust setae; the shape and setation of the uropods; adult males are further characterised by the presence of a large bluntly rounded robust seta at the inferodistal angle of the carpus. These species constitute the first record of the family from the Indian Ocean.

A new species of Cheiriphotis (Crustacea : Amphipoda: Corophiidae: Protomedeiinae) from the coast of Southeastern Brazil, with a key to species in the genus

A new species of the Cheiriphotis, C. neotropicalis n. sp. is herein described. The specimens were collected from the coast of southeastern Brazil at the latitude 24°07’S and in 17 meters deep. Cheiriphotis neotropicalis sp. nov. is characterized by male gnathopod 2 palm transverse with three rounded lobes separated by excavations, a strong spine at defining corner of the palm to hind margin; uropod 3 uniramous, ramus with 2 robust setae on inner margin and 1 distal robust seta, 5 long setae on distal margin; telson broader than long, lateral margin naked. A key to the species in the genus Cheiriphotis is provided.

A NEW SPECIES OF AEGIDAE (ISOPODA, CYMOTHOIDA) FROM THE SOUTH CHINA SEA

Aega nanhaiensis sp. nov. is described and figured from the South China Sea. Brief comments are given on the relationship of the new species to allegedly related species of the genus. Aega nanhaiensis is characterized by the expansion of articles I and 2 of the antennular peduncle, a moderate eye-size, a large distal, robust seta on the propodus of pereopod 3, and the shape and setation of the uropods.

Feeding by Philoponella vicina (Araneae, Uloboridae) and how uloborid spiders lost their venom glands

Feeding by uloborid spiders is unusual in several respects: cheliceral venom glands are absent; prey wrapping is extensive (up to several hundred metres of silk line) and severely compresses the prey; the spider’s mouthparts usually never touch the prey; and the entire surface of the prey is covered with digestive fluid. This paper presents observations on Philoponella vicina O. Pickard-Cambridge, 1899, which provide possible causal links between these traits. The spider begins ingesting soon after it wets the prey, gaining access to the prey’s interior through a broken cuticle that was broken during wrapping and by digestion of the prey’s membranes. The more abundant of the two types of wrapping lines is also digested, but the remaining shroud of wrapping silk is dense and filters digested prey particles. Robust setae on the palpal tarsus and the spread position of the anterior legs during feeding probably protect the spider from contact with the digestive fluid. Spiders extracted about 65% of the wet contents of the prey, but feeding was slow and involved substantial water evaporation. We propose that selection in uloborid ancestors to recover wrapping silk led to increased wetting of the prey’s surface and that compressive wrapping facilitated this wetting. These traits could have led to loss of the now superfluous cheliceral poison glands.

Aega sheni, a new species of Aegidae (Crustacea: Isopoda: Cymothoida) from southern China and Australia

Aega sheni sp. nov. from Chinese and Australian waters, is described and figured. This species is characterized by the plate-like expansion of antennule peduncle articles 1 and 2, very large eyes (nearly making contact), numerous robust setae on the inferior margins of the ischium of pereopods 2 and 3, large distal lobe on the propodus of pereopods 1–3, shape and setation of the uropods, and the rounded pleotelson posterior margin. Aega sheni has been recorded at depths of 300–435 metres.

Ringanui, a new genus of stygobitic amphipod from New Zealand (Amphipoda: Gammaridea: Paraleptamphopidae)

A new genus is established for two new species of paraleptamphopid amphipods. Both species are stygobites inhabiting alluvial aquifers up to at least 18 m beneath the Canterbury Plains in New Zealand. First collected by Charles Chilton in 1882, these two species became confused with Paraleptamphopus subterraneus. The new genus, Ringanui, is a significant step in resolving this confusion. Ringanui differs from Paraleptamphopus on several characters and is most easily recognised by diverse gnathopods, the first of which is enlarged relative to gnathopod 2. The two species are described and illustrated in detail. They differ in size and gnathopod characteristics, but other differences are small. Ringanui koonuiroa is the smaller species and is most easily recognised by the single, very long robust seta defining the palm of gnathopod 1. The second species, R. toonuiiti, is the larger, but its palmar defining spine is relatively short. Both species occur together at the same locations and apparently in the same habitat.