Antennal Articles Research Articles

Not all male bees posses thirteen antennal segments: New megachilid species from the Afro-Arabian and Afrotropical regions (Apoidea: Anthidiini: Pseudoanthidium) with deviant numbers of segments

Male bees (Apoidea) typically possess antennae with 13 articles, with only a few exceptions reported, none of which are from the Megachilidae family. In this study, we describe two new species of the megachilid tribe Anthidiini that display an unusual characteristic – their males have only 12 antennal segments. We attributed these species, Pseudoanthidium omanicum sp. nov. from the Arabian Peninsula, and P. ethiopicum sp. nov. from Ethiopia, to the subgenus Pseudoanthidium (Mesanthidiellum), previously known only from Sub-Saharan Africa. Notably, the male of a third species in this subgenus, P. (Mesanthidiellum) sakaniense (Cockerell, 1936) was also found to have only 12 antennal segments. Further investigation revealed that males with antennae with 12 articles are also present in the closely related subgenus Pseudoanthidium (Branthidium), suggesting that this phenomenon may be more widespread yet often overlooked. A broader review indicates that deviations from the typical 13 antennal articles are known in 10 genera of bees and account for less than 0.5% of all bee species. We conclude that this trait has evolved independently across different bee lineages. However, the specific function of a reduced number of antennal articles remains elusive. http://www.zoobank.org/urn:lsid:zoobank.org:pub:56B808FB-E4F2-46A9-9B54-850AF83263D0

Cryptops (Trigonocryptops) didi sp. n. (Chilopoda: Scolopendromorpha: Cryptopidae): expanding the cryptopid biodiversity in a Brazilian hotspot of subterranean fauna

ABSTRACT A new troglobitic Cryptops species is described in Lage Branca Cave, Upper Ribeira karst, São Paulo state, Brazil. Cryptops (Trigonocryptops) didi sp. n. is closely related to Cryptops (T.) iporangensis Ázara and Ferreira, 2013 and Cryptops (T.) iheringi Brölemann, 1902. However, it differs from them in several aspects, including the number of saw teeth on the tibia and tarsus 1 of the ultimate legs, the sutures on the first antennal article, the sutures on the first trunk tergite, and the presence of trigonal sutures on the anterior sternites. Cryptops (Trigonocryptops) didi sp. n. is the second troglobitic species of Cryptops found in the caves of the Upper Ribeira karst area. This discovery enhances the diversity of troglobites in one of the richest cave systems in South America, the Areias Cave System. It also underscores the importance of ongoing faunistic inventories in one of the most extensively sampled areas for subterranean fauna in Brazil. We also transferred Cryptops (T.) iporangensis to the subgenus Cryptops Leach, 1814. http://www.zoobank.org/urn:lsid:zoobank.org:pub:7BAB8A6B-047B-4752-BD5C-34AF0BAE4195

Descriptions of new and rare crabs associated with coral rubble and sponges from Kanyakumari, southeastern Arabian Sea, southern India (Decapoda: Brachyura: Epialtidae and Pilumnidae)

Three new brachyuran crab species are described from coral rubble and sponges collected in the southern Indian state of Tamil Nadu. The epialtid, Acanthophrys keeae n. sp., was obtained from coral rubble and is the first species from the genus reported from the Indian Ocean. It is most similar to A. costatus Griffin & Tranter 1986, from eastern Australia, but can be distinguished by the proportionately longer postorbital spine, more strongly granulated gastric region, relatively less inflated and narrower branchial region, sinuous outer margin of the basal antennal article which has the median part concave, almost smooth merus of the cheliped, more elongate male anterior thoracic sternum, more triangular male pleon, and the distal two-thirds of the male first gonopod being almost straight. The pilumnid, Latopilumnus ajmali n. sp., was found in the sponge, Callyspongia (Cladochalina) diffusa (Ridley, 1884), and is characterised by its carapace and pereiopods being covered by a relatively dense coat of short setae with only scattered simple long setae, and the dorsal carapace surface being almost smooth with the regions poorly demarcated. Vellumnus intonsus n. sp. (Pilumnidae) was present in coral rubble, is morphologically most similar to V. penicillatus (Gordon, 1930) (Hong Kong) and V. pygmaeus Takeda, 1977 (Japan) but can be separated by the lateral lobule of the front being separated from the frontal lobes by a deep cleft, the more prominently convex supraorbital margin, triangular external orbital tooth, presence of larger granules on the cheliped carpus and chela, and the distal part of the male first gonopod is proportionately stouter and distinctly hooked.

New and rare deep-sea majoid crabs (Crustacea: Brachyura) from Papua New Guinea.

Additional spider crab (superfamily Majoidea) material from four major French-led expeditions to the Papua New Guinea region were examined in this study. One new genus and four new species from the families Inachidae and Oregoniidae are described. Dorhynchus profundus n. sp. is close to D. rostratus (Sakai, 1932) but can easily be separated by the shape of the ambulatory dactylus and the proportionately lower protogastric spines. Achaeus pholcus n. sp. is unusual in that it occurs in deeper waters (beyond 500 m), and can be separated from A. lacertosus Stimpson, 1857, A. villosus Rathbun, 1916, and A. brevidactylus Sakai, 1938, by its distinctive carapace shape, structure of the frontal margin, regions of the carapace, antennular fossa, ambulatory dactylus, male pleon, and proportions of the chela. Parapleisticantha aie n. sp. is closest to P. japonica Yokoya, 1933, but differs in its proportionately longer carapace, more elongated basal antennal article, longer third maxilliped ischium and the relatively less curved male first gonopod with the distal part differently structured. A new genus (Orbicantha n. gen.) with one new species (Orbicantha sacrebleu n. gen., n. sp.) is also described; it is allied to Pleistacantha Miers, 1879, Parapleisticantha Yokoya 1933, and Pleisticanthoides Yokoya, 1933, but is distinctive in its subcircular carapace, shorter regions, short pseudorostral spines, possession of spines on the gastric, cardiac and branchial regions, some of which have rounded tips, a short ocular peduncle, a very short third antennal article, a quadrate epistome, and the more reduced P4 and P5. New records from the family Epialtidae are also reported: Griffinia gilloloensis (Rathbun, 1916), Hyastenus borradailei (Rathbun, 1907), and Oxypleurodon luzonicum (Rathbun, 1916). The taxonomy of Grypachaeus tenuicollis Takeda, 1978 (Oregoniidae) and Griffinia lappacea (Rathbun, 1918) (Epialtidae) is also discussed.

Chirostyloid and galatheoid squat lobsters (Decapoda: Anomura) from Andaman and Nicobar Islands, India, with three new species

ABSTRACT The squat lobster fauna of the Andaman and Nicobar waters, India is known to be represented by more than 40 species from 19 genera and six families. Seven species, including three new to science, collected from six dedicated surveys of the Fishery Oceanographic Research Vessel Sagar Sampada during 2011–2019 are described. Gastroptychus valdiviae Balss, 1913 is redescribed based on the syntype and the newly collected material. Grimothea krishaha sp. nov. and an unidentified species provisionally assigned to Grimothea Leach, 1820 are reported. These two species of Grimothea differ from known congeners in the spination on the carapace, pleon, antennule, antenna and third maxilliped. Examination of the syntype and newly collected specimen revealed that Munida vigiliarum Alcock, 1901 should be transferred to Leptonida Macpherson and Baba in Machordom et al., 2022. Leptonida vigiliarum comb. nov. is here redescribed. Trapezionida aequispina sp. nov. differs from related species in the spination on the carapace, and in the shape and relative lengths of the second to fourth pereopod dactyli. Trapezionida bharuchai sp. nov. differs from related species in the carapace morphology, the presence of a mesial spine on the antennal peduncle second article, and the armature on pereopods. Leiogalathea sp. does not resemble known congeners in morphological aspects, but because of the poor condition of the unique specimen presently available for study, formal description is deferred in the hope that additional material will be collected. With this report, the number of species reported from the region increases to 47. http://www.zoobank.org/urn:lsid:zoobank.org:pub:A82CE9B3-BF67-4282-97DF-20D37CF02464

Four new species of Monographis Attems, 1907 (Diplopoda, Polyxenida, Polyxenidae) from Vietnam

Four new species of penicillate millipedes from the genus Monographis Attems, 1907, collected from various regions in Vietnam, are described. They show distinctive morphological characteristics on the labrum, telotarsus, and sensilla on antennal article VI. Monographis cattienensis sp. n., M. tamdaoensis sp. n., and M. thatsonensis sp. n. belong to the group with sensilla on article VI arranged in a crescent, whereas M. konkakinhensis sp. n. is in a group with sensilla arranged in a triangle. Molecular analysis of Monographis konkakinensis sp. n., M. tamdaoensis sp. n. and M. thatsonensis sp. n. shows that these species differ genetically from other Monographis congeners. Additionally, two previously described subspecies, Monographis kraepelini malayanus Nguyen Duy-Jacquemin & Condé, 1966; and M. k. sabahnus Condé & Nguyen Duy-Jacquemin, 1984; are elevated to species, namely Monographis malayana Nguyen Duy-Jacquemin & Condé, 1966 and M. sabahna Condé & Nguyen Duy-Jacquemin, 1984.

Taxonomic Accounts and Phylogenetic Positions of the Far East Asian Centipedes Scolopocryptops elegans and S. curtus (Chilopoda: Scolopendromorpha).

The epigean centipede genus Scolopocryptops Newport, 1844 consists of two monophyletic lineages, the "Asian/North American" and "Neotropical/Afrotropical" groups. Most of the "Asian/North American" species bear the complete sulcus/sulci along the lateral margin of the cephalic plate and sternites lacking sulci, whereas Japanese Scolopocryptops elegans (Takakuwa, 1937) bears short lateral sulci on the cephalic plate and Taiwanese Scolopocryptops curtus (Takakuwa, 1939) lacks the cephalic marginal sulci, and both species bear a longitudinal sternal sulcus. The taxonomic accounts of S. elegans and S. curtus were revisited in this study based on newly collected specimens. We found that these two species share a characteristic of the second maxilla, that they lack the transparent margin on the dorsal brush, which distinguishes them from other "Asian/North American" species. Scolopocryptops elegans and S. curtus can be distinguished from each other by the characters of their antennal articles, cephalic plate, forcipular coxosternite, tergite 23, and coxopleuron. Phylogenetic analyses using nuclear 28S ribosomal RNA and mitochondrial cytochrome c oxidase subunit I sequences confirmed that S. elegans and S. curtus are closely related and form a single clade sister to a clade comprising all the other "Asian/North American" Scolopocryptops species.

A new brackish tanaidacean, Sinelobus kisui sp. nov. (Crustacea, Peracarida, Tanaidacea), from Japan, with a key to Sinelobus species and barcode information from two loci

We describe the new brackish tanaidid species Sinelobus kisuisp. nov. from Hagi, Yamaguchi, Japan. Sinelobus kisui is similar to S. barretti and S. vanhaareni in having antennal article 2 with one outer distal seta, the dorsodistal crotchet on pereopods 2 and 3 carpi shorter than half propodus length, and pereopodal carpi 2–6 with five distal crotchets, but differs from them in having (1) the inner of two ventro-subdistal circumplumose setae on the maxillipedal endite longer than the outer; (2) the maxillipedal endite with one mid-inner spiniform seta; (3) the pereopod-1 propodus with one middle setulate seta; and (4) the pleopod-1 protopod lacking inner plumose setae. Our study confirmed that character states of the chelipeds in strongly dimorphic males are useful in Sinelobus taxonomy. We determined partial sequences for the cytochrome c oxidase subunit I (COI; cox1) and 18S rRNA (18S) genes in S. kisui for future DNA barcoding and phylogenetic analyses. Morphological and/or molecular data reveal that S. kisui also occurs in Kagawa and Osaka, Japan. A key to species in Sinelobus is provided.

Otostigmus (Otostigmus) xizangensis n. sp., from China and a case of sexual dimorphism in the subgenus Otostigmus (Otostigmus) Porat, 1876 (Chilopoda, Scolopendromorpha, Scolopendridae).

Otostigmus (Otostigmus) xizangensis n. sp., a new species of subgenus Otostigmus Porat, 1876 from Xizang, China, is described and illustrated. The new species is diagnosed as follows: antennae 1719 articles (mainly 19), basal antennal articles cylindrical; forcipular tooth-plate with 4 teeth; tergites (5) 620 with complete paramedian sutures; well-developed lateral margination on tergites (6) 921; ultimate leg prefemora with four rows of spines, leg 20 with one tarsal spur. The coxopleural process of O. (O.) xizangensis n. sp. exhibits remarkable sexual dimorphism, being long and curved in females, short and straight in males.

Description of a New Hamatipeda Species, with an 18S Molecular Phylogeny (Crustacea: Tanaidacea: Typhlotanaidae).

We describe a new typhlotanaid species, Hamatipeda kohtsukai sp. nov., collected from between 167 and 488 m depth in the Sagami Sea, Japan. This is the first record of Hamatipeda from the northern hemisphere. Hamatipeda kohtsukai resembles Hamatipeda trapezoida from the Subantarctic region in having pereonites 1-3 widest anteriorly (not rectangular), but differs from it in the length ratio of antennal articles 4/5; the number of setae on the dactyli of pereopods 1-3, ischia of pereopods 4-6, and carpi of pereopods 4-6; the shape of the unguis of pereopods 4-6; and the shape of the uropodal endopod. We determined partial sequences for the cytochrome c oxidase subunit I (COI; cox1) and 18S rRNA (18S) genes in H. kohtsukai. A phylogenetic reconstruction based on the 18S sequences recovered a highly supported Typhlotanaidae clade containing H. kohtsukai and Typhlotanais mixtus, with Paranarthrura sp. (Agathotanaidae) as the sister taxon. A key to species of Hamatipeda is presented.

A new species of Expanathura (Crustacea: Isopoda: Anthuroidea) from Iriomote Island, Japan, with a note on male polymorphism.

We describe Expanathura monile sp. nov. from Iriomote Island, Okinawa, Japan, northwestern Pacific. This species resembles E. collaris, E. macronesia, and E. haddae in having very broad uropodal rami, a broad telson, and a moderately shortened pleopod 1 endopod, but differs from these three species in the female having (1) the head with a dorsal V-shaped band of brown pigmentation, (2) the antennular flagellum with 34 articles, (3) antennal peduncular article 2 with an outer triangular projection, (4) the uropodal endopod longer than wide, (5) the uropodal exopod with an acute triangular projection, (6) an oval telson, and (7) the posterolateral setae on the telson similar in length. We present a revised key to known species in the genus Expanathura and briefly discuss the male polymorphism observed in E. monile.

An enigmatic new species of Belostoma Latreille from central-western Brazil (Heteroptera: Belostomatidae: Belostomatini).

The new species Belostoma inusitatum is described and illustrated based on specimens from the west side of the Araguaia-Tocantins basin, in Mato Grosso state in central-western Brazil. This new species is assigned to the B. triangulum species group and compared with its congeners. A key and distribution map for the species of this group are included. The three-articulated antenna without lateral projections of B. inusitatum n. sp. is documented for the first time in Belostoma. Also, the uncommon shape of the prosternal keel, the distinct reduction of the hemelytral membrane, and the diverticulum of the phallosoma sharply incised at the posterior margin are reported for this new species. A discussion about the reduction in the number of antennal articles and the size of the hemelytral membrane in Belostoma and Abedus is presented.

Cinusa nippon n. sp. (Isopoda: Cymothoidae) Parasitic in the Buccal Cavity of Coastal Puffers (Tetraodontiformes: Tetraodontidae) from Japan, with the First Specimen-Based Record of the Isopod Genus from the Pacific Region.

Cinusa nippon n. sp. is described as the second species of the genus from ovigerous females and adult males found in the buccal cavity of three species of coastal puffers [vermiculated puffer, Takifugu snyderi (Abe, 1989) (type host); panther puffer, Takifugu pardalis (Temminck and Schlegel, 1850); and fine patterned puffer, Takifugu flavipterus Matsuura, 2017], in the southern Sea of Japan off western Honshu, Japan. The female of the new species is distinguished from that of its single congener, Cinusa tetrodontis Schioedte and Meinert, 1884, by the shape of pereonite 1 (straight lateral margins with slightly produced anterolateral angles in the new species vs. rounded anterolateral sides and angles in C. tetrodontis). The number of recurved robust setae on the female's maxilliped article 3 is also different between the two species: C. nippon n. sp. has two robust setae, while C. tetrodontis has three robust setae. Moreover, the male of the new species is differentiated from that of C. tetrodontis in the number of antennal articles and recurved robust setae on the maxilla and maxilliped. Cinusa nippon n. sp. represents the first specimen-based record of the genus from the Pacific region. An amended diagnosis of the genus is provided.

A new species of Unixenus Jones, 1944 (Diplopoda, Polyxenidae) found in far north Queensland, Australia

Unixenus Jones, 1944 (Polyxenidae) is the dominant genus of penicillate millipedes found throughout mainland Australia. Herein, a new species, Unixenus mossmanus sp. nov., is described from coastal forest near Mossman. The new species is similar to U. karajinensis, sharing the same sensilla pattern on antennal article VI and the same arrangement of leg setae. Unixenus mossmanus sp. nov. differs by having only 3 ornamental trichomes c per side (v. 5-9), 2 pairs coxal glands in the male (v. 6 pairs), and a slender claw (v. robust). These characteristics differ from those of U. karajinensis, which has 5–9 ornamental trichomes c; 6 pairs coxal glands in male; and a robust claw structure. 18S sequence of Unixenus mossmanus sp. nov. is included.

The identity of Hyastenus pleione (Herbst, 1803) and description of a new species from China (Decapoda, Brachyura, Majoidea, Epialtidae)

Abstract The poorly known epialtid crab, Hyastenus pleione (Herbst, 1803), from the Indian Ocean is re-described on the basis of the type material. Large sized specimens of a similar looking species from China are here assigned to a new species. The new species differs from H. pleione in having fewer large granules on the carapace, a blunt distal angle of the basal antennal article with the outer margin slightly constricted medially, possessing only one branchial granule along the lateral margin of the carapace, and has a relatively more elongate male first gonopod with the subdistal part weakly dilated.

A new species of Zeuxo (Crustacea: Peracarida: Tanaidacea) from Japan, with remarks on carapace pigmentation as a potentially useful taxonomic character

ABSTRACT We describe Zeuxo ezoensis sp. nov. from Hokkaido, Japan. This species closely resembles Z. phytalensis, Z. shitipingensis and Z. turkensis in having the pleopodal endopod with one inner plumose seta, maxillipedal palp article 4 with one outer simple seta, the left mandible with a wide, denticulate lacinia mobilis and one bifurcate accessory seta, and the right mandible with a peg-like lacinia mobilis and two accessory setae. It differs from them in having (1) antennal article 6 longer than wide, (2) the distal region of the maxillipedal endite with four spiniform setae and two circumplumose setae, (3) maxillipedal palp article 2 with one outer simple seta, (4) the chelipedal carpus with three or four dorsodistal simple setae, (5) the chelipedal dactylus with one inner simple seta, (6) the pereopod-1 basis with one or two ventrodistal simple setae, (7) the pereopod-1 carpus with one ventrodistal simple seta, and (8) the uropod with four or five articles (basal article plus three or four ramus articles). Partial nucleotide sequences for the cytochrome c oxidase subunit I (COI) gene (655 nt) from Z. ezoensis specimens from four localities in Hokkaido showed Kimura 2-parameter (K2P) divergences of 0–0.5% and 0.6–1.5% within and between populations, respectively. Based on the COI data, we examined the phylogenetic position of Z. ezoensis within Zeuxo. Six specimens used for morphological observations and 10 specimens used for COI sequencing showed a similar dorsal pigmentation pattern on carapace. We briefly discuss the validity of using this pattern as a diagnostic character in Zeuxo taxonomy. http://zoobank.org/urn:lsid:zoobank.org:pub:6CB565DB-DAFF-41EF-A06D-EAAE2F619C31

New records of the drywood termite, Incisitermes platycephalus (Light, 1933) (Isoptera, Kalotermitidae), from Central America and senior synonym of I. nigritus (Snyder, 1946)

New World species of the genus Incisitermes Krishna, 1961 range from California to Peru.  The soldier of this genus is notable for the incised anterior margin of the pronotum and the elongated third antennal article.  I report the broad occurrence of Incisitermes platycephalus (Light, 1933) from extreme southern Mexico to the Pacific coast of Nicaragua. Incisitermes nigritus (Snyder, 1946) from Guatemala is a junior synonym of I. platycephalus.  Among Incisitermes, I.  platycephalus is characterized by its small size, dark imago, and dorsoventrally compressed soldier head capsule.

Paradoxapseudes shimojiensis sp. nov. (Crustacea: Tanaidacea: Apseudidae) from a submarine limestone cave in Japan, with notes on its chelipedal morphology and sexual system

ABSTRACTWe describe Paradoxapseudes shimojiensis sp. nov. from a submarine limestone cave at Shimoji-jima Island, Ryukyu Islands, southwestern Japan. This species resembles five species (P. basibidens, P. bassoprofundo, P. bermudeus, P. edgari, and P. heroae, among 17 congeners) that bear a long pleotelson, but differs from them in having (i) a naked antennal article 1, (ii) the maxillipedal basis with one inner distal plumose seta, (iii) the chelipedal basis with one dorsodistal and one ventro-subproximal simple setae, (iv) the pereopod-1 basis with four dorsal simple setae longer than the width of the pereopod-1 basis, but without ventrodistal spiniform setae, (v) the pereopod-1 merus with three mid-inner ventral simple setae, and (vi) the pleopodal protopod with two inner plumose setae. We determined partial nucleotide sequences for the cytochrome c oxidase subunit I (COI) and 18S rRNA (18S) genes in P. shimojiensis for future use in DNA barcoding and phylogeny. Paradoxapseudes shimojiensis has serial ridges on the inner surfaces of the left and right chelipedal bases that quite resemble the stridulatory organs in harvestmen (Opiliones); by analogy, we speculate that these ridges may be stridulatory sound-producing organs. Two specimens had both a fully-developed marsupium and genital cone, suggesting that P. shimojiensis is simultaneously hermaphroditic.http://zoobank.org/urn:lsid:zoobank.org:pub:391C3C0F-8845-4496-A27D-936384F9E59D

Drywood Pest Termite Cryptotermes brevis (Blattaria: Isoptera: Kalotermitidae): a Detailed Morphological Study of Pseudergates.

The Kalotermitidae Cryptotermes brevis (Walker) presents colonies that lack a true worker caste. They have totipotent worker-like individuals named pseudergates. Few studies have characterized the morphology of immature instars, including pseudergates. In order to identify these instars and characterize the pseudergates, we conducted a comparison between morphometric and morphological variations among immature individuals of C. brevis colonies. Juvenile hormone analog (JHA) was used in the first instar nymphs to induce regressive molts and compare morphological differences between nymphs and pseudergates. Results showed the existence of three larval instars and four nymphal instars. These immatures were morphologically characterized. Individuals classified as third instar larvae presented white body, 10 to 12 antennal articles, absent or small non-pigmented compound eyes, and absence of wing buds. Pseudergates presented pigmented abdomen and sclerotized cuticle, 10 to 12 antennal articles, and absent or small compound eyes, and few specimens had large pigmented compound eyes and absence of wing buds. First instar nymphs had pigmented abdomen and sclerotized cuticle, 10 to 12 antennal articles, both large non-pigmented and pigmented compound eyes, the presence of wing buds. Bioassays using JHA on first instar nymphs resulted in a large percentage of nymph-soldier intercastes. We concluded that abdomen pigmentation and sclerotized cuticle are good characters to differentiate pseudergates from larvae and the absence of wing buds is a good character to differentiate pseudergates from nymphs. Our findings not only contribute to the basic biological and morphological information of this species but also help to identify correctly pseudergates in further studies that involve applied bioassays.

A new species of Tanaopsis (Crustacea: Tanaidacea) from Japan, with remarks on the functions of serial ridges and grooves on the appendages

We describe Tanaopsis japonica sp. nov. from intertidal and nearshore habitats around Hokkaido Island, northern Japan. This species closely resembles T. chotkarakde Bird & Bamber, 2000 and T. rawhitia Bird, 2011 in having the uropod with the endopod biarticulate and the exopod uniarticulate, but differs from them in the following characters: pereonite 4 as long as pereonite 5; mandibles lacking the molar; the number of simple setae on the antenna, propodal palm, and dactylus of pereopods 1–3; the number of spiniform setae on the cutting surface of the chelipedal dactylus; and the number of setae on the pleopods. We also determined a nearly complete nucleotide sequence for the 18S rRNA gene in T. japonica. In both sexes, Tanaopsis japonica sp. nov. bears serial ridges and grooves on the chela, antennule, and antenna. Parallel, fringed hatch marks on the chelipedal dactylus may function in stridulation. A series of denticulate ridges on the dorsal surface of antennal article 2 faces the ventral side of article 1 of the antennule, where there is a ventral series of slight grooves. Although the ranges of motion of the antennule and antenna were unclear, the ridges and grooves on the antenna and antennule may also function in producing sound. Two outer series of ridges on the chela, together with an outer furrow on the chela, may function in digging, by allowing bottom-sediments to be efficiently pushed aside.