Exopod Of Pleopod Research Articles

A new species of Caecidotea (Crustacea: Isopoda: Asellidae) from a well in the western slope of Mexico, with occurrence records of C. alvarezi.

Caecidotea isabelae sp. nov., a new freshwater asellid isopod species from Jalisco, Mexico is described. During fieldwork in 2021, we discovered eight new populations of freshwater isopods belonging to the genus Caecidotea. One population corresponded to a new species, Caecidotea isabelae sp. nov., while the other seven populations were identified as Caecidotea alvarezi. These populations are reported from freshwater bodies on the western Trans-Mexican Volcanic Belt, expanding the distributional range of C. alvarezi through the state of Jalisco. The new species can be distinguished of their congeners mainly by the protopod of pleopod I triangular with 3 retinacula, exopod of pleopod III with 6 presutural setae, pleopod IV with 3 spines in the proximal external margin. The present study increases the number of known epigean asellid species in Mexico to 12, and the number of currently described Caecidotea species in North America to 102 with three subspecies.

Description of two new janirid isopods (Isopoda, Asellota, Janiridae) from Korean waters.

Two janirid isopods, Caecijaera ciliata sp. nov. and Janiralata truncata sp. nov., are reported from Korean waters in this study. Caecijaera ciliata sp. nov. differs from its congeners by the following features: pereonites 47 with large simple setae on the midline of the posterior tergite margins; the pleotelson is angled proximolaterally; the antennula is six-articled; the basis of pereopod is serrated superiorly; and the appendix masculina is not coiled. Janiralata truncata sp. nov. can be distinguished from its related species by the following characteristics: the lateral margin of the cephalothorax has an acute projection anterolaterally; all coxal plates of the pereonites are visible dorsally; male pleopod has a pair of small rounded projections distally near the fusion line of the two first pleopods; the exopod of pleopod has two plumose setae on the distomedial margin.

Nebaliella ochotica sp. nov.—new deep-sea species of leptostracans (crustacea: phyllocarida: leptostraca) from the North-west Pacific

Eleven specimens of leptostracans were collected with the help of the camera-epibenthic sledge (C-EBS) in August 2015 at depth 3287–4469 m in the Kurile depression of the Sea of Okhotsk and in the Pacific Ocean to the east of the Boussole Strait (Kurile Islands) during the Russian-German expedition Sokho-Bio. All these specimens relate to new species of genera Nebaliella Thiele, 1904 from family Nebaliidae: N. ochotica. Nebaliella ochotica sp. nov. varies from the other species of Nebaliella by the unique values of the ratio of the rostral flange to exposed keel (2 : 1 in N. ochotica, 3 : 1 in N. antarctica, and 1 : 1 in other species). In this species, article 2 of mandible palp has 1 long seta by distodorsal corner, without stout spicular process and small setae; exopod of pleopod 1 has 5 stout long spicular setae on lateral border, with 1–2 stout long spicular setae on terminal border and with 1–3 distal spicular setae and 10–17 simple setae on medial border. Moreover, N. ochotica differentiates from N. brevicarinata, N. extrema and N. kurila by the absence of carina on anterolateral lower corner of carapace, arom N. brevicarinata and N. extrema—by the absence of ventroproximal tuberculate process on rostrum, and from N. antarctica and N. kurila—by compound articles 1 and 2 on peduncle of antenna.

Two new species of deep-sea leptostracans (Crustacea: Phyllocarida: Leptostraca) from the North-West Pacific

Small collections of leptostracans (4 specimens and 1 defective specimen) was collected with the help of the epibenthic sledge (EBS) in August 2012 in the deep-sea basin at depth 5245–5421 m in the region to east of the Kuril-Kamchatka Trench during the Russian-German KuramBio expedition. All these specimens relate to two new species of genera Sarsinebalia and Nebaliella from family Nebaliidae. Sarsinebalia pseudotyphlops sp. nov. differ from S. kunyensis, S. cristoboi and S. urgorrii by compound eyes gud. Eyes of S. pseudotyphlops have not discernible ommatidia and pigment. S. pseudotyphlops differ from S. typhlops and S. biscayensis by next characteristic: supra-orbital plate of S. pseudotyphlops reach only basal third of eye dorsally; antennular flagellum is 1.6 length of antennular scale; S. pseudotyphlops has 2-segmented endopod of maxilla 2; lateral border of furcal rami is by this species smooth, without set; exopod of pleopod 1 has by S. pseudotyphlops with 7 small and 2 long spines on dorsolateral border and 1 stout spine and 4 very long setae on apex; protopod of pleopod 4 has by S. pseudotyphlops on distal border between exopod and endopod nearly rectangular process. Moreover, S. pseudotyphlops differ from two other species of compound and arming of pleopods 5 and 6. Nebaliella kurila sp. nov. separate from the other species of Nebaliella the unique characters of compound articles 1 and 2 on peduncle of antenna, exopod of pleopod 1, and minimal value for this genus ratio length of pleopod 6 to length of pleonite 6. Moreover, N. kurila has carina on anterolateral lower corner of carapace; ratio of the rostral flange to exposed keel 1:1; 6-segmented palp of maxilla 1 and endopod of toracopod 8; and has not proximalventral tuberculate process on rostrum and stout spinulose process on article 2 of mandibular palp.

A new species of freshwater isopod (Sphaeromatidea: Sphaeromatidae) from an inland karstic stream on Espíritu Santo Island, Vanuatu, southwestern Pacific

Exosphaeroides quirosi is described from a karstic stream and its associated cave sink located 390 m above sea level and 23.5 km inland from the east coast of Espíritu Santo (Vanuatu, SW Pacific ocean). This is the first purely freshwater sphaeromatid isopod reported from an oceanic island, and is a new example of colonization of an oceanic island freshwater habitat by a typically marine taxon. E. quirosi differs from any other representative of the family in the peculiar condition displayed by the exopod of pleopod 4, which has a falcate outline, is distinctly longer than the corresponding endopod, and has the medial margin of the proximal segment produced into a foliaceous endite. Seemingly, the sexual dimorphism expressed in the presence/absence of a setulose fringe on the pereopods has not been recorded in any other sphaeromatid. Even though the peculiar pleopod 4 and the fusion pattern of pleonites—with complete incorporation of pleonite 1 to rest of pleonites—could suggest a new genus to accommodate the new species, it is included here in the broad Exosphaeroma s. l. cluster, from which most freshwater sphaeromatids seem to derive. This is done with the caveat that it is incertae sedis in Exosphaeroides until such time as a comprehensive revision of Exosphaeroma and related genera has been undertaken. E. quirosi appears to be a Exosphaeroma-derived species with an unusual pleopod 4 and fusion of pleonite 1 to the remainder of the pleon; these features being here regarded as species-level apomorphies within a morphologically diverse genus.

Sursumura affinis sp. n.—a New Deep-Sea Species of the Family Munnopsidae (Isopoda: Asellota) from the Region of Australia and New Zealand

We describe here Sursumura affinis sp.n., a new deepwater species of the family Munnopsididae (Isopoda: Asellota) from the South Australian and South Fiji hollows. It is characterized as follows: the dorsum of the body is not granulated, bearing short setae; the pleonite lacks a dorsal spine; the pleotelson bears 5 dorsal spines; the preanal projection of the pleotelson is well-developed; the exopod of pleopod 4 is relatively slender and short. In morphology, the new species is most similar to S. abyssalis (Wolff, 1962) from the Tasmanian Sea. This is the second species of the genus described from the Australian–New Zealand region.

A new genus and species of leptostracan (Crustacea: Malacostraca: Phyllocarida) from Guana Island, British Virgin Islands, and a review of leptostracan genera

Saronebalia guanensis, a new genus and species of leptostracan, is described from material discovered in shallow subtidal waters of Guana Island, British Virgin Islands. The specimens were collected from light traps placed on sediment and by hand from the green alga Halimeda. Saronebalia differs from other leptostracans most notably in the morphology of the antennule and the eighth thoracic limb: the articles of the antennular flagellum are fused and bear dense clusters of setae, and the eighth thoracic limb is elongate. While its eyes, like those of Nebalia, are non-tuberculate, it shares the rostral spine, dentate process of antennular article 4, and serrate pleopodal protopods of Levinebalia and Paranebalia. Specimens of the new genus lack the setal row of the exopod of pleopod 1, a complex feature characteristic of Dahlella, Levinebalia, Nebalia and Paranebalia. A cladistic analysis of the 10 leptostracan genera, using 30 morphological characters from these features and others, also supports the status of Saronebalia as a new genus. Saronebalia represents the third leptostracan genus to be recorded from the Caribbean Sea.

Three new species of Benthana Budde-Lund (Isopoda, ‘Philosciidae’) from Brazil

Three new species of Benthana Budde-Lund, 1908 are described from material collected near São Fancisco de Paula, a town in the north-east of the southernmost Brazilian State, Rio Grande do Sul (RS). The new species are: Benthana serrana sp. nov., Benthana trinodulata sp. nov. and Benthana araucariana sp. nov. (from Araucaria Forest). The presence of more than one nodulus lateralis on coxal plate VII, a characteristic not previously known in the genus, is reported. New occurrences of B. picta (Brand, 1833) and B. taeniata (Araujo and Buckup, 1994) are also recorded. A method is given for defining the shape of the exopod of pleopod 1 of the male based on morphometry.

Macedonethes stankoi n. sp., a rhithral oniscidean isopod (Isopoda: Oniscidea: Trichoniscidae) from Macedonia

Abstract Macedonethes stankoi n. sp. is described, a truly aquatic species with special morphological adaptations to life in running water. Diagnosis of Macedonethes stankoi n. sp. (Fig. 1): Species with the characters diagnostic for Macedonethes Buturović, 1955 (see also Tabacaru 1993). Blind. Body large (up to 15.7 mm long), rather convex. Defined mostly by characters interpreted as adaptations to life in rhithral habitats: cephalon hypognathous, antennular article 3 and aesthetascs reduced to varying degree (from slightly developed with two aesthetascs to almost totally reduced); pereopods 1–4 subchelate, i.e. with elongate carpus opposed to propodus and dactylus (enabling the animal to attach tightly to the substrate); sternum of pereonite 5 with unique clasping structures (presumably facilitating copulation); exopod of male pleopod 1 remarkably dilated mediodistally; endopod of male pleopod 2 with arched apical article; exopods of pleopods 2–5 with long plumose setae on posterior margins; epimera of pleonites 3–5 well developed. Types and locality: Holotype male (Macedonian Museum of Natural History, Skopje; Inv. No. 2783); Macedonia, Jakupica Mt., slopes of Solunska glava peak, from a spring in the cave at the source of the Babuna River, 1500 m asl (UTM-EM31), 18.08.2000, leg. G. Poliić. Paratypes: 4 males and 2 females as holotype (Inv. No. 2784); 2 males and 1 female as holotype, except in author's collection; 1 male and 1 female as holotype, except in Museo Zoologico “La Specola”, University of Florence, Italy. Spelaeonethes castellonensis Cruz & Dalens, 1989 clearly differs from the characteristics of Spelaeonethes species, particularly in structures of the male merus 7 and the endopods of male pleopods 2. Published descriptions and illustrations demonstrate obvious close relations with the type species of Macedonethes, M. skopjensis Buturovic, 1955, especially regarding all characters considered diagnostic for that genus. Therefore, the new combination Macedonethes castellonensis (Cruz & Dalens) is proposed. A detailed description (including color plates), further discussion of adaptations, and data on other aquatic oniscids are presented in an Electronic Supplement.

On the Occurrence of Paradella Dianae (Menzies, 1962) a Genus and Species of Sphaeromatidae (Isopoda, Flabellifera) in the Arabian Sea

The species under consideration, has been obtained from the Bulleji coast, Karachi, among intertidal algae and mud. It is worth noting that all the species placed in the genus Paradella have been recorded from the Americas, the Marshall Islands and from the eastand westcoasts of Australia. In the Indian Ocean, P. dianae has been recorded only from Western Australia. The genus and species are now recorded for the first time from the Arabian Sea, Indian Ocean. The measurements given are the total lengths of the body along the midline from the anterior margin of the head to the posterior apex of the telson. Material examined. ? Bulleji near Karachi, Pakistan. Among the intertidal algae Ulvafasciata, Padina tetrastromatica, and Caulerpa racemosa on a mud bottom; collected in February 1984. 2 adult males, 5 mm; 4 subadult males, 3.1-4.99 mm; 5 ovigerous females, 3.3-4.2 mm; 18 non ovigerous females, 2.5-4.5 mm. Descriptive remarks. ? The present specimens correspond closely to the description and illustrations given by Harrison & Holdich (1982) except in some minor details. The adult male (fig. 1A) differs from the Australian specimens while it agrees with the Brazilian specimens (Pires, 1982: 53, figs. 21, 22) in having distinct transverse ridges on posterior margins of pereonites 5 to 7 and 2 pairs of slightly larger granules lateral to the submedian pairs of tubercles on the pleotelson. Antennae 1 and 2 have 11 and 16 segments in the flagella of the adult male instead of 12 and 13, respectively (Harrison & Holdich, 1982: 103). The Ara bian Sea specimens also have a granulated pleon (fig. 1A) while illustrations by Harrison & Holdich (1982, figs. 6a, q) show no granules. Pereopod 1 (fig. 1C) is robust, pereopods 1 to 7 with a simple accessory unguis. The endopod of pleopod 1 (fig. ID) is not so acutely produced as that of the Australian specimen figured by Harrison & Holdich (1982: 104, fig. 6j). The exopod of pleopod 3 (fig. IF) is with an articulation. The pleotelson of the ovigerous female (fig. 2A) is rather more granular than in the Australian ovigerous female (Harrison & Holdich, 1982, fig. 6q), and the submedian pair of tubercles has a tendency towards fusion but is not com pletely fused.