Caudal Setae Research Articles

Five new species of the genus Tripylella (Nematoda: Enoplida: Tripylidae).

Five new species of the genus Tripylella are described, two from México, one from Fátima, Portugal, one from Quito, Ecuador, and one from California, USA. Tripylella mexicana sp. n. is characterized by its short body (average 0.74 mm), short pharynx (average 161 μm), short tail (average 117 μm), presence of an excretory pore and small setae distributed sparsely along the body, the presence of body pores, the posterior position of the subventral teeth in relation to the small dorsal tooth with all teeth in contiguous stomal chambers, the finely-striated cuticle with many anastomoses, the non-protruding vulval lips, and the presence of sclerotized pieces in the vulval region. Tripylella muscusi sp. n. is characterized by its body length (average 0.94 mm), pharynx length (average 201 μm), tail length (average 140 μm), the anterior position of the subventral teeth in relation to the small dorsal tooth in a single stomal chamber, the presence of an excretory pore, the presence of body pores and sparse somatic setae, the finely-striated cuticle with sparse anastomoses, protruding vulval lips and sclerotized oval-shaped pieces present in the vulval region. Tripylella quitoensis sp. n. is characterized by the short body length (average 0.72 mm), the short outer labial setae, the short pharynx (average 175 μm), the location of the anterior subventral teeth and posterior dorsal tooth in the same stomal chamber, the short tail (average 98 μm), the apparent absence of an excretory pore, presence of body pores, presence of somatic setae, a finely-striated cuticle, non-protruding vulval lips, and very small oval sclerotized pieces in the vulva. Tripylella fatimaensis sp. n. is characterized by the short body, (average 0.74 mm) long, by the length of the pharynx (average 180 μm), the length of the tail (average 110 μm) and in the length of its reduced diameter portion, 45-58 μm, the presence of an excretory pore, body pores and three pairs of caudal setae (one pair each latero-ventral, latero-dorsal and ventral). Tripylella dentata sp. n. is characterized, and differs from all the species of the genus, by the presence of two adjacent stomal chambers, with two large teeth, one dorsal and one ventral, in the posterior stomal chamber and two subventral teeth in the anterior smaller chamber, short body (average 0.85 mm), pharynx length (average 209 μm), tail length (average 115 μm), the apparent absence of an excretory pore, the presence of two cervical setae in a lateral position, and by the presence of conspicuous pores along the body.

The Australian Monstrilloida (Crustacea: Copepoda) II. Cymbasoma Thompson, 1888.

Monstrilloid copepods collected during the past two decades from zooplankton surveys in reef and coastal areas of Australia were analyzed. A first contribution included the taxonomic analysis of three genera of the Monstrilloida, Monstrillopsis Sars, 1921, Maemonstrilla Grygier & Ohtsuka, 2008, and the newly described Australomonstrillopsis Suárez-Morales & McKinnon, 2014. In this document a taxonomic analysis of the species belonging to the genus Cymbasoma Thompson, 1888 is provided. A total of 28 species were found, most of them being undescribed. Seventeen species were described based on females only and eight on male specimens while three species were described from both sexes. Males of Australian species of Cymbasoma are distinguished by details of the genital complex, body size and proportions, ornamentation and processes of the cephalic region, number of caudal setae, and the characteristic structure or ornamentation of the genital lappets. Two main groups of males were distinguished on the basis of the number of caudal setae (3 or 4). As for the females, 20 of the 25 new species of Cymbasoma have fifth legs with an unarmed inner lobe and three setae on the outer lobe; one of these species (C. jinigudira sp. nov.) belongs to the C. longispinosum species-group (sensu Üstün et al. 2014). Another group, consisting of five species, has only two setae on the outer (exopodal) lobe. There were no Australian species of Cymbasoma with a single lobe. A species group, named after C. agoense, is proposed to include species sharing a globose body and a female fifth leg with a large endopodal lobe and an outer (exopodal) lobe with two setae. The females of the new species of Cymbasoma from Australia can be distinguished from their known congeners by unique combinations of characters including the type of body ornamentation, body size and shape, antennule armature and proportions, the presence of distinctive features of the legs 1-4, the presence/absence of processes on the genital compound somite, and the presence/absence of a constriction of the anal somite. We report the occurrence of two previously described species, C. agoense Sekiguchi, 1982 from Japan and C. bali Desai & Krishnaswamy, 1962 from India in Australian waters. Considering the addition of the 25 new species here described, the number of nominal species of the genus is now 66. A key to the Australian species of Cymbasoma (males and females) and a map showing their occurrence in Australia are also provided.

A new species of the genus Nannopus (Copepoda, Harpacticoida, Nannopodidae) from the mudflat of Ganghwa Island, Korea

Abstract During a study of the harpacticoid copepods from the intertidal mudflat of Ganghwa Island, in the Yellow Sea of Korea, a new species of the genus Nannopus was discovered. Nannopus ganghwaensis shared the character of seven elements in P4 exp-3 with N. flexibilis Lilljeborg, 1902, N. didelphis Fiers & Kotwicki, 2013, and N. hirsutus Fiers & Kotwicki, 2013. However, the new species was clearly distinguished from the three congeners by the combination of the following character states: (1) absence of the integumental window on the dorsal surface of cephalothorax, (2) the lateral margins of urosomites is not densely hirsute, (3) the distal small seta of P4 endopod is naked, (4) the innermost seta of P5 exopod fused to the segment, (5) the inner most distal seta of P2 enp-2 is 1.7 times longer than the outer spine of its segment, and (6) caudal seta IV slightly inflated at its insertion site, and pinnate. Additionally, the male of new species differed from N. didelphis by the following characters: (1)...

Two New Species of Echiuricopus n. gen. (Copepoda, Poecilostomatoida) Associated with Echiurans from the Yellow Sea

Two new species of poecilostomatoid copepods associated with echiurans are described from an intertidal mud flat in the Yellow Sea. A new genus Echiuricopus is created to accommodate two new species, E. aprilis and E. tenuipes. Major differences between the two new species are displayed in body length, length of caudal ramus seta I, length/width ratio of leg 5 exopod, and armature of the first antennular segment. Echiuricopus n. gen. is closely related to the genus Goidelia Embleton, 1901, but is distinguished from the latter chiefly by having seven caudal setae, a clawlike process on the first antennular segment, one claw-like process on the maxillary syncoxa, the absence of an inner coxal seta on legs 1-4, different armatures on legs 1-4, and an elongate leg 5 exopod.

A new species of the genus Elaphoidella Chappuis (Copepoda, Harpacticoida) from a cave in the south of Thailand

Specimens of a new species,Elaphoidella sanoamuangaen. sp., were collected during an investigation of cave-dwelling copepods in a tourist cave in the Phuket mountain range, South Thailand, and the new species is described and depicted herein.Elaphoidella sanoamuangaen. sp. fits intoElaphoidellagroup VII sensu Lang (1948). The new species is most similar toE. schubartiChappuis, 1936. The differential characters for females of the two species are: (a) the free margin of the anal operculum, (b) the number of ventral spinules on the anal somite, (c) the shape of the caudal rami, (d) the shape of the inner terminal caudal seta, (e) the segmentation of Endp P1, (f) the armature formula of Endp-2 P2-P4, and (g) the size of the setae on P5.

Naupliar and Metanaupliar Development of Thysanoessa raschii (Malacostraca, Euphausiacea) from Godthåbsfjord, Greenland, with a Reinstatement of the Ancestral Status of the Free-Living Nauplius in Malacostracan Evolution.

The presence of a characteristic crustacean larval type, the nauplius, in many crustacean taxa has often been considered one of the few uniting characters of the Crustacea. Within Malacostraca, the largest crustacean group, nauplii are only present in two taxa, Euphauciacea (krill) and Decapoda Dendrobranchiata. The presence of nauplii in these two taxa has traditionally been considered a retained primitive characteristic, but free-living nauplii have also been suggested to have reappeared a couple of times from direct developing ancestors during malacostracan evolution. Based on a re-study of Thysanoessa raschii (Euphausiacea) using preserved material collected in Greenland, we readdress this important controversy in crustacean evolution, and, in the process, redescribe the naupliar and metanaupliar development of T. raschii. In contrast to most previous studies of euphausiid development, we recognize three (not two) naupliar (= ortho-naupliar) stages (N1-N3) followed by a metanauplius (MN). While there are many morphological changes between nauplius 1 and 2 (e.g., appearance of long caudal setae), the changes between nauplius 2 and 3 are few but distinct. They involve the size of some caudal spines (largest in N3) and the setation of the antennal endopod (an extra seta in N3). A wider comparison between free-living nauplii of both Malacostraca and non-Malacostraca revealed similarities between nauplii in many taxa both at the general level (e.g., the gradual development and number of appendages) and at the more detailed level (e.g., unclear segmentation of naupliar appendages, caudal setation, presence of frontal filaments). We recognize these similarities as homologies and therefore suggest that free-living nauplii were part of the ancestral malacostracan type of development. The derived morphology (e.g., lack of feeding structures, no fully formed gut, high content of yolk) of both euphausiid and dendrobranchiate nauplii is evidently related to their non-feeding (lecithotrophic) status.

Metacyclops woni n. sp., a New Cyclopoid Species (Copepoda: Cyclopoida: Cyclopidae) from Cambodia

A new cyclopoid species belonging to the genus Metacyclops Kiefer, 1927 is described, based upon the specimens from a temporary pool in a forest of Mt. Phnom Domnak Dambouk, situated in the southwestern part of Cambodia. Metacyclops woni sp. nov. is characterized by its quite short caudal rami, about 2.5 times longer than wide, with a spinule row on anterior quarter of lateral margin. This new species belongs to the species group with the spine formula 3,4,4,3 of swimming legs 1-4. Among the members of the species group with the combination of characters of 11-segmented antennule and a single apical spine on the second endopodal segment of leg 4, it most resembles M. deserticus Mercado-Salas and Suarez-Morales, 2013 from Mexico in carrying an outermost caudal seta slightly longer than the innermost caudal seta and an apical spine on the second endopodal segment of leg 4 slightly shorter than the segment. However, it differs clearly from the present new species by much longer caudal rami with lateral caudal seta at nearly halfway of lateral margin of the ramus and smooth posterior margin of intercoxal sclerites of legs 1-4. This is the first record of the genus Metacyclops from Cambodia and the fourth one from Southeast Asia.

A new marine cyclopoid copepod of the genus Neocyclops (Cyclopidae, Halicyclopinae) from Korea.

A new cyclopoid species of the genus Neocyclops Gurney, 1927 is described. Type specimens were collected from a beach on south-western coast of the Korean Peninsula by rinsing intertidal coarse sandy sediments. Neocyclops hoonsooi sp. n. is most characteristic in showing the conspicuous chitinized transverse ridges originating from the medial margins of the coxae of all swimming legs. The new species is most similar to Neocyclops vicinus, described from the Brazilian coast, and Neocyclops petkovskii, from Australia. All three species share a large body size (more than 750 µm long), the presence of an exopodal seta on the antenna, two setae on the mandibular palp, the same seta/spine armature on the third endopodal segment of leg 3 (3 setae + 3 spines), and the fairly long inner distal spine on the third endopodal segment of the female leg 4. However, Neocyclops hoonsooi sp. n. differs from both species by the much shorter caudal rami (less than 1.7 times as long as wide) and the shorter dorsal caudal seta VII. Furthermore, Neocyclops hoonsooi is clearly distinguished from Neocyclops vicinus by the 10-segmented antennule (vs 12 segments in Neocyclops vicinus), and from Neocyclops petkovskii by the elongate inner distal spine on leg 5 exopod and the 3-segmented leg 5 in male (vs 4-segmented in Neocyclops petkovskii). A tabular comparison of characters separating Neocyclops hoonsooi from its closest allies and a key to Neocyclops species from the Indo-Pacific Ocean are provided. This is the first record of the genus Neocyclops from the northern Pacific.

Description of Trischistoma abharensis n. sp. (Nematoda: Trischistomatidae) and first record of Tripylella intermedia (Bütschli, 1873) Brzeski & Winiszewska-Ślipinska, 1993 (Nematoda: Tripylidae) from Iran.

Two populations of the genera Trischistoma and Tripylella were recovered from the rhizosphere of grapevines and mosses growing on alder trees in Zanjan and Guilan provinces, respectively, Iran. The nematodes were identified as Trischistoma abharensis n. sp. and Tripylella intermedia, respectively. Trischistoma abharensis n. sp. is characterized by having females with body length 1069-1322 μm, presence of sparse somatic setae on the sublateral body, absence of ventromedian cervical setae, a distinct dorsal tooth directed anteriorly, absence of post-vulval uterine sac, and tail with one pair of subdorsal caudal setae. Males were not found. Tripylella intermedia is characterised by having females with body length 905-990 μm, annulated cuticle, stoma with two chambers: with dorsal tooth lying in posterior buccal chamber, and one large subventral and one small subventral tooth, respectively lying in posterior and anterior buccal chambers, cardiac glands large, composed of six fused cells, and tail 121-155 μm long, ventrally bent, anterior half broad, then suddenly narrowing, with posterior half tapered narrowly and cylindrically. The phylogenetic relationships of both species were analysed using sequences of the partial small subunit (SSU) and D2/D3 expansion segments of large subunit (partial LSU) of ribosomal RNA genes and are discussed.

A new subterranean Maraenobiotus (Crustacea: Copepoda) from Slovenia challenges the concept of polymorphic and widely distributed harpacticoids

Maraenobiotus slovenicus sp. nov. is described from subterranean waters of a very cold, temporary karstic spring in the vicinity of Velika Pasica cave, central Slovenia. A detailed examination of numerous specimens reveals a low level of morphological variability in this population. Morphological characters traditionally used in the genus Maraenobiotus Mrázek, 1893 would identify our population as a subspecies of the polymorphic and widely distributed M. vejdovskyi Mrázek, 1893. This species was reported from the Palearctic, with at least six accepted subspecies, some of which have been reported in sympatry or parapatry, sometimes even without any apparent niche partitioning. One of these subspecies, M. vejdovskyi truncatus Gurney, 1932, originally described from the UK and later on also reported from Italy and Japan, shares with our population the extremely reduced female principal caudal setae. However, a closer examination of the caudal armature and other characters reveals significant differences between these disjunct populations. We propose a hypothesis of distinct species within the M. vejdovskyi-complex, and critically review all recognized and some unrecognized morphotypes and subspecies. As a result, three new species names are proposed for previously reported populations from Italy and Japan: Maraenobiotus galassiae sp. nov.; M. isidai sp. nov.; and M. pescei sp. nov. Four subspecies of M. vejdovskyi are now elevated to the full specific rank: M. anglicus Gurney, 1932; M. arctica Löffler; M. tenuispina Roy; and M. truncatus Gurney, 1932. This hypothesis remains to be tested using molecular (and other) tools, but can serve as a viable alternative to the concept of polymorphic and widely distributed freshwater harpacticoids.http://zoobank.org/urn:lsid:zoobank.org:pub:92302CF9-21BA-4454-A3DD-337BB7152DCE

A new species and a new record of Trischistoma Cobb, 1913 (Nematoda: Enoplida: Trischistomatidae) from Shanxi Province, China.

This paper describes a new species and gives a new record and a re-description of a known species of Trischistoma Cobb, 1913. Trischistoma taiguensis sp. nov. is characterized by having one pair of caudal setae on the tail; female body length of 562-699 µm, a = 35-42, b = 4.1-4.7, c = 11-14, c' = 3.9-4.6 and V = 79-82%. For the first time, Trischistoma pellucidum Cobb, 1913 is recorded from Shanxi Province, China. The phylogenetic relationships among species in the genus Trischistoma were analyzed using data from the SSU (small subunit) and D2/D3 expansion segments of the LSU (large subunit) rDNA sequences. These analyses confirmed that T. taiguensis sp. nov. and T. pellucidum differ from other known members of the genus for which sequences are available in GenBank.

Two new species of ectinosomatid copepods (Harpacticoida: Ectinosomatidae) from the Caribbean coast of Colombia

Biological samples from the lagoonal system Laguna Navío Quebrado, Caribbean Colombian coast, yielded 2 undescribed species of harpacticoid copepods of the family Ectinosomatidae. The first species, Halectinosoma arangureni sp. nov., is most closely related to H. langi Wells, 1967, H. curticorne (Boeck, 1873) and H. abyssicola (Bodin, 1968), but diverges from these congeners in: 1) the length-width ratio of the maxillipedal basis; 2) the outer caudal seta(II)/caudal ramus length ratio; 3) details of the mandible palp and blade; 4) the length of the inner exopodal seta of P5; 5) the accessory seta on the male P5 exopod, and 6) a T-shaped incision on the male third urosomite. The second species, Pseudobradya gascae sp. nov. closely resembles P. robusta Sars, 1910 and P. barroisi (Richard, 1893), but diverges from these species by: 1) the number of antennular segments in the female; 2) the absence of a seta on the antennary EXP2; 3) proportions of the maxilliped; 4) the relative length of P1EXP; 5) caudal seta III/caudal ramus length ratio, and 6) the unusually long middle seta of P5EXP. Both genera are recorded for the first time in Colombia.

Record of Kelleria reducta (Copepoda: Poecilostomatoida: Kelleriidae) from the Caribbean coast of Colombia

From the analysis of plankton samples from a coastal lagoon system of northern Colombia a female specimen of the poecilostomatoid copepod Kelleria reducta Gómez, 2006 was recorded. This species was originally described from the Mexican Pacific and it is the only species of the genus known from the Americas. The specimen from Colombia bears the diagnostic features of K. reducta as originally described, but shows some subtle differences in the basis of the maxilliped, the caudal rami length/width ratio, the ornamentation of the caudal setae IV and V, and the body length. The morphological range of this species is complemented and additional comparisons are made with respect to 6 species recently described from Korea and Indonesia. Among them, K. reducta most closely resembles K. indonesiana Mulyadi, 2009 but they can be separated by differences in the last endopodal segment of antenna, the P4ENP, the P5, and the mandibular blade. This is the first record of the genus in Colombia and in the Caribbean basin; it represents a significant range extension of the species from the eastern Tropical Pacific to the western Caribbean.

Two new species of the genus Wellsopsyllus (Copepoda; Harpacticoida;Paramesochridae) from the Yellow Sea.

A study of benthic harpacticoids from the intertidal zone of Gosapo Beach, on the west (Yellow Sea) coast of Korea, resulted in the discovery of two species of Wellsopsyllus Kunz, 1981. The first new species, Wellsopsyllus (Wellsopsyllus) egregius sp. nov., was allocated to the nominotypical subgenus by a combination of three characters: 1) a 3-segmented P4 exopod, 2) 1-segmented P2-P3 endopods, and 3) a P1 endopod-2 with one apical seta. However, it can be clearly distinguished from its congeners by the following characters: 1) a caudal rami with two blunt setae and the seta VII located sub-distally, 2) a P2 and P3 endopod represented by a small blunt process, and 3) the semioval shape of P5. The second new species was placed in the subgenus Scottopsyllus Apostolov & Marinov, 1988 according to the 3-segmented exopod and 2-segmented endopod of P4. Wellsopsyllus (S.) koreanus sp. nov. exhibits a unique combination of characters: 1) a dimpled distal margin of the female P5 endopodal lobe armed with two subequal setae, 2) a caudal seta V consisting of a stout spine-like base with a long cylindrical seta-like portion arising subdistally, and 3) a distinct bundle of five long inner setules on the P1 basis. We present a summary of the characters of all species in the genus Wellsopsyllus and propose an updated key for their identification.

To add five species of Cyclopidae (Cyclopoida - Copepoda) to the fauna of freshwater zooplankton of Vietnam

In Vietnam, according to Dang Ngoc Thanh et al. 1980, Ho Thanh Hai et al. 2007, 11 species belonging to seven genus Eucyclops, Paracyclops, Ectocyclops, Tropocyclops, Mesocyclops, Thermocyclops, Microcyclops and Halicyclops are recorded in fresh waters of Vietnam. Based on analysis of many samples collected from various waters in Vietnam during 2002-2008, five species belonging to Cyclopidae including Macrocyclops albidus, Paracyclops affinis, Eucyclops euacanthus, Tropocyclops candidiusi, and Tropocyclops bopingi that are firstly found in Vietnam. All of these species are described in detail in the paper. Typical characters on taxonomy are used for identification of species such as: structure of antennule, shape of receptaculum seminis (R.S.), armature of connecting plate, coxopodite and basipodite of P4, the third segment of endopodite of P4 (Enp3 P4), leg 5, the proportion of the terminal spines of Enp3 P4, the spines formula of exopodite of P1-P4, and of the caudal ramie, relative length of caudal setae. Macrocyclops albidus and Paracyclops affinis are cosmopolite species. Eucyclops euacanthus was recorded in Asean, China and India. The Tropocyclops candidiusi was described first time from Taiwan (China) by Harada (1931), Tropocyclops bopingi was firstly described from Guangdong (China) by Dumont (2006), that widely distributed in south China Up to now, 16 species belonging to 7 genera of Cyclopidae-Cyclopoida are recorded in fresh waters of Vietnam. The amount of species of Cyclopidae of Vietnam can be surely increased, when genera Microcyclops, Thermocyclops and Mesocyclops should be revised in species composition.

Two new nematodes, Pseudelzalia longiseta gen. nov., sp. nov. and Paramonohystera sinica sp. nov. (Monhysterida: Xyalidae), from sediment in the East China Sea

Pseudelzalia longiseta gen. nov, sp. nov. and Paramonohystera sinica sp. nov. from subtidal sediment in the East China Sea are described. Pseudelzalia is characterized by 6 labial papillae and 10 cephalic setae, cylindrical buccal cavity, elongate (>2 anal body diameter) spicules, and conico-cylindrical tail devoid of terminal setae. It differs from Elzalia by the absence of terminal setae. Pseudelzalia longiseta sp. nov. is 647–853 μm long, has 7–8 μm long cervical setae, 11–14 μm long caudal setae, 25–41 μm long spicules about 2.1–2.7 anal diameter, and pointed tail-tip. Paramonohystera sinica possesses 12 cephalic setae, a character found in four congeners: Paramonohystera buetschlii (Bresslau and Schuurmans Stekhoven in Schuurmans Stekhoven, 1935, Paramonohystera pilosa Boucher, 1971, Paramonohystera concinna Lorenzen, 1977 and Paramonohystera halerba Fadeeva and Belogurov, 1987. It differs from P. buetschlii by shorter body (933–1023 μm versus 2000–2200 μm); from P. pilosa by the much shorter spicules (79–88 μm versus 167 μm) and narrower head (13–16 µm versus 32 µm); from P.concinna by smooth cephalic setae (versus segmented); and from P. halerba by the absence of two rows of setae on the ventral side of the tail (versus present). Based on the evaluation of nominal species, we recognize 14 valid species and provide an emended diagnosis and a tabular key for Paramonohystera.http://www.zoobank.org/urn:lsid:zoobank.org:pub:474B8F17-AED7-4078-8176-DFC499B78526

A new iranian species of <em>Uroleucon</em> Mordvilko, 1914 (Hemiptera, Aphididae) from specimens in the Natural History Museum collection

Uroleucon (Uromelan) helichrysi sp. n. (Hemiptera, Aphididae, Aphidinae: Macrosiphini) is established from Iranian apterous and alate viviparous females caught on Helichrysum sp. (Asteraceae) and preserved in the collection of the Natural History Museum (BMNH) in London. The number of setae on the first tarsal segments (5), the number of caudal setae (20 to 28), the presence of abdominal marginal tubercles on abdominal segments 2 to 4, and the size of the cells of the siphuncular reticulation (relatively small) allow the new species to be distinguished from other Palaeartic species of the subgenus Uromelan. Blackman and Eastop’s key to apterae on Helichrysum is modified to include the new species. urn:lsid:zoobank.org:pub:E2B89D59-05FD-4A9E-AD78-B3C302219A10

The Australian Monstrilloida (Crustacea: Copepoda) I. Monstrillopsis Sars, Maemonstrilla Grygier & Ohtsuka, and Australomonstrillopsis gen. nov.

Monstrilloid copepods were collected during zooplankton surveys in reef and coastal areas of Australia. Representatives of all four genera of the Monstrilloida (Monstrilla Dana, Monstrillopsis Sars, Cymbasoma Thompson, and Maemonstrilla Grygier & Ohtsuka) were recorded. In this contribution a taxonomic analysis of specimens belonging to the latter two genera is provided, and a new genus described. The genus Monstrillopsis was represented exclusively by male specimens, on the basis of which three new species are described: Mon. hastata sp. nov., Mon. boonwurrungorum sp. nov., and Mon. nanus sp. nov. These are distinguished from each other and previously described species of this genus by details of the genital complex (or genital apparatus), body size, ornamentation of the cephalic surface, number of caudal setae, and characteristic modifications of the fifth antennular segment. All have distinctive characters not associated with sexual modifications, which will ease the task of matching females collected in future studies. Australomonstrillopsis gen. nov. is proposed to accommodate a male specimen with a unique combination of characters including massively developed caudal rami, cephalic perioral protuberances, and absence of an inner seta on the first exopodal segment of legs 1-4, among other characters. The new genus is monotypic and contains A. crassicaudata sp. nov. Three of the four new species of Maemonstrilla (Mae. ohtsukai sp. nov., Mae. hoi sp. nov., and Mae. protuberans sp. nov.) belong to the Mae. hyottoko species group, and the remaining one, Mae. crenulata sp. nov., belongs to the Mae. turgida group. Each of the new species of Maemonstrilla from Australia can be distinguished from its known congeners by a unique combination of characters including the type of body reticulation, body size, antennule and body proportions, distinctive characters of the swimming legs, details of the antennular armature, and the presence/absence of a posteroventral process on the genital compound somite. With the addition of the four new species of Monstrillopsis and the four of Maemonstrilla described herein, the number of species in these genera has increased to 13 and 11 species, respectively. In no case did congeneric species co-occur, hinting that there may be a rich species diversity yet to be discovered within the Australian Monstrilloida.

Three species of Ditrichocorycaeus (Copepoda, Cyclopoida, Corycaeidae) from Korean waters, with new identification parameters

Three species of Ditrichocorycaeus [D. dahli (Tanaka, 1957), D. lubbocki (Giesbrecht, 1981), and D. subtilis (Dahl, 1912)] are first redescribed from southern area of Jeju Island, Korea. Morphological details such as mouthparts, ornamentation of genital double-somite, spine lengths of legs, and proportional lengths of caudal setae, are provided as new identification keys separating each species within Ditrichocorycaeus and/or each genus within Corycaeidae. In particular, the number and location of each segment on the body and antenna are re-examined and precisely defined. Also, few valid morphological characters of this genus distinguishing it from other genera are newly proposed as follows: 1) prosomes of both sexes are five-segmented; 2) basis of maxilliped with relatively longer proximal seta than in other genera.

Graeteriella(Graeteriella)longifurcata, new species, a stygobitic cyclopoid species (Copepoda: Cyclopoida: Cyclopidae) from Central Vietnam

Abstract A new cyclopoid species belonging to the genus Graeteriella is described from a limestone cave in central Vietnam. This is the first record of the genus from the Oriental region. It is assigned as the fifth member of the subgenus Graeteriella Rylov, 1948 based on its unique 1-segmented leg 5 armed with two spines/setae, lacking protopodal seta, and 2-segmented rami of legs 2–4 in female. The new species is distinguished from its congeneric species of the subgenus from Europe by having longer caudal rami with spiniform outer caudal seta, by the absence of coxal seta on leg 4, and by the seta/spine armature of leg 5, that is, an inner stout spine and a shorter outer pinnate seta on the free exopodal segment of leg 5.