Male Setae Research Articles

Leptolaimus petrelense n. sp. (Plectida: Leptolaimidae), a new nematode species from the Petrel lagoon, central Chile

Summary During a survey on the biodiversity of nematodes in the Petrel lagoon (central Chile), a population of Leptolaimus was found in sediment samples. Morphological, morphometric and molecular data indicated that the recovered nematode is a new species. This nematode belongs to the group in which the males only have four pre-cloacal tubular supplements present, and females have no supplements. The new species can be separated from the other species of the group by the length of both males and females (843-1060 μm), the tail length (118-208 μm), the shape of the gubernaculum, and the arrangement of the caudal setae in males (a pair of ventral precloacal setae at level of spicules, a pair of dorsal post-cloacal setae, two subventral and two subdorsal caudal pairs. The differences from closely related species L. gerlachi, L. praeclarus, L. octavus, L. hydrothermalis, L. vipriensis, and L. hadalis are discussed. The recovered population is described herein as Leptolaimus petrelense n. sp.

Two psammobiont species of Anomalohalacarus (Acari, Halacaridae) from South Korea.

The genus Anomalohalacarus Newell, 1949, which is known to occur exclusively inhabiting sand, has not been previously reported from Korea. During a recent survey of the meiofauna from several intertidal sandy beaches in South Korea, we found both sexes of two psammobiont halacarids, Anomalohalacarusangustus sp. nov. and A.biformis Abé, 1996. Both species are similar to each other in sharing an undivided posterior dorsal plate, three and two setae on the anterior and posterior epimeral plates, respectively, three bipectinate setae on tibia IV, and four ventral setae on tarsus I. However, A.angustus sp. nov. is distinguished from A.biformis by the absence of areolae posteriorly on the anterior dorsal plate, a much more slender posterior dorsal plate, a pair of subgenital setae on the genital foramen in females, and seven branched perigenital setae on the genitoanal plate in males. The feature of branched perigenital setae in males is reported for the first time in the genus Anomalohalacarus. The Korean specimens of A.biformis agree well with the original description from Japan, except for the number of ventral bipectinate setae on tibia II. This study presents (re)descriptions of both species with detailed illustrations and provides a dichotomous key to Anomalohalacarus species, including the new species, based on morphological characters. The genus Anomalohalacarus is reported for the first time in South Korea.

First record of a tantulocaridan, Microdajus sp. (Crustacea: Tantulocarida), from the northwestern Atlantic

A putative new species of tantulocaridan is reported parasitizing a species of typhlotanaid (Tanaideacea) from the Gulf of Mexico at depths up to 2767 m. The tantulocaridan belongs to Microdajus Greve, 1965, species of which are all known from tanaid hosts in the superfamily Paratanoidea. Tantulocaridan samples included newly settled tantulus larvae, early stages of trunk development and developing males; parasites were found attached to anterior appendages (antennules and pereopods) or bodies of hosts. This material likely represents a new species but the condition and number of available specimens precludes a formal description. The putative new species is most similar to Microdajus aporosus Grygier and Sieg, 1988 and Microdajus tchesunovi Kolbasov and Savchenko, 2010 in having an endopodal seta on each of the sixth thoracopods (lacking in other species). Microdajus tchesunovi is the only described species of Microdajus with males bearing unsegmented sixth thoracopod protopods; this character is also found on the present specimens. Males of the newly reported tantulocaridan can be distinguished from those of M. tchesunovi based on protopod 1-5 morphology and setation of the pits on the cephalothorax (fewer setae in males of the western Atlantic specimens compared to M. tchesunovi). This is the first species of Microdajus reported from the western Atlantic and the first tantulocaridan known from the Gulf of Mexico or northwestern Atlantic.

Three new species of Laelapidae mites (Mesostigmata) parasitic of species of Akodon (Rodentia: Cricetidae: Sigmodontinae) on the basis of female, male and deutonymph specimens

Three new species of Androlaelaps (Mesostigmata: Laelapidae) are described on the basis of the female and male specimens, and deutonymph for two of them. Each of the new species parasitizes a different species of Akodon (Rodentia: Cricetidae: Sigmodontinae). Diagnostic characteristics support that the three new species are included in the Androlaelaps rotundus species group, and may be differentiated between them because of the length of proximal seta in coxa I; distances j5-j5, j6-j6 and z5-z5 setae in males and females; and length of st3, and st1 setae in females. Out of the seven species included in A. rotundus species-group, only the males of three of them are known, while immature stages are unknown. The new information herein provided contributes to a better knowledge of the laelapid mites and is essential to further investigate the epidemiological role of these mites as vectors of pathogens.

Paragnomoxyala papillifera sp. nov. (Nematoda: Monhysterida) from the Bohai Sea, China

A new free-living marine nematode species of the family Xyalidae from Laizhou Bay of the Bohai Sea, China is described and illustrated herein. Paragnomoxyala papillifera sp. nov. is characterized by large funnel-shaped buccal cavity, circular amphidial fovea located posterior to buccal cavity, straight spicules with slightly curved distal end, gubernaculum absent, four papilliform precloacal supplements, tail conico-cylindrical with two ventral embossments in males and having longitudinal rows of cervical setae and subventral caudal setae in males. The new species is easily identified from other two recorded species in the genus by having papilliform precloacal supplements and ventral embossments along conical portion of tail of males. A pictorial key for three species of Paragnomoxyala and comparative table of three species with important characteristics are provided.

Cirolana bambang, a distinctive new species of Cirolana Leach, 1818 (Crustacea: Isopoda: Cirolanidae) from Bitung, Indonesia

Cirolana bambang sp. nov. from Bitung, North Sulawesi, Indonesia is described. The species can be recognised by generally smooth body with small, acute, submedian nodules on pleonites 4-5 and the anterior dorsal surface of the pleotelson together with a flat, pentagonal frontal lamina, linguiform and sexually dimorphic pleotelson with the dorsal surface covered by short setae in males, deeply bifid uropod apices, and a conspicuously large robust seta on the superodistal angle of pereopod 1 ischium. Cirolana bambang sp. nov. appears to belong to a group of Indo-West Pacific Cirolana with prominent penial process, a large robust seta on the superodistal angle of pereopod 1 ischium and the presence of setae on dorsal surface of pleotelson and or uropod in males. The most similar species are Cirolana comata Keable, 2001; Cirolana dissimilis Keable, 2001; Cirolana aldabrensis Schotte Kensley, 2005; and Cirolana somalia Schotte Kensley, 2005. Cirolana kiliani Müller, 1993 and C. somalia are found not to belong to the Cirolana'parva-group'.

Underwater attachment using hairs: the functioning of spatula and sucker setae from male diving beetles.

Males of Dytiscinae beetles use specialized adhesive setae to adhere to female elytra during underwater courtship. This coevolution of male setae and female elytra has attracted much attention since Darwin. However, there has been little examination of their biomechanical functioning despite increasing knowledge on biofibrillar adhesion. Here, we report and compare, for the first time, the mechanisms of underwater attachment using two hair types, the primitive spatula and derived 'passive' sucker, found in male diving beetles. Results from interspecific scaling of protarsal palettes and adhesion by single seta suggest better performance in the later-evolved circular (sucker) setae. Spatula setae with a modified shallow sucker and channels use the combined mechanisms of suction and viscous resistance for adhesion. Velocity-dependent adhesion provides sufficient control for resisting the female's erratic movements while also detaching easily through slow peeling. Direction-dependent shear resistance helps reorient setae surfaces into a preferred direction for effective adhesion. Seta deformation using different mechanisms for circular and spatula setae reduces the force that is transmitted to the contact interface. A softer spring in spatula setae explains their adhesion at lower preloads and assists in complete substrate contact. Attachment mechanisms revealed in adhesive setae with modified spatula and passive suckers provide insights for bioinspired designs of underwater attachment devices.

Two new species of Spinicaudata (Crustacea: Branchiopoda) in south India with a key to Leptestheriella and Eocyzicus

Five species of Leptestheriella (Daday 1923) have been described from India, but variability in many characters suggestsonly two are valid: L. nobilis (Sars 1900) and L. sarsi Daday 1923. We add Leptestheriella simhadrii sp. nov. which isdistinct in its carapace and growth line ornamentation and in females of having the endopodital palp on the fifth endite ofthe third thoracopod slightly longer than the sixth endite. A key is provided to distinguish the three species. Eight de-scribed and one unconfirmed species of Eocyzicus (Daday 1915) have been reported from India. We add Eocyzicus pal-palis sp. nov. from south India and present a key to local species. Eocyzicus palpalis sp. nov. is distinct by reason of itsornamentation of the carapace, the presence of a palp on the fourth endite of the third thoracopod and the fifth endite of the sixth and seventh thoracopods which bears a palp and plumose setae in males.

Psammophilous halacarid mites (Trombidiformes, Halacaridae) from the North Coast of São Paulo State, Brazil

Five halacarid species are reported from the Brazilian coast for the first time. Scaptognathides delicatulus, formerly known only from its type locality in Kuwait; Scaptognathus gibbosus, known from Galapagos and Somalia; and Scaptognathus insularis known from northeastern Australia, have their distributions extended. Along with these new records, Halacaroides antoniazziae sp. nov. and Acarochelopodia caissara sp. nov. are described. Halacaroides antoniazziae sp. nov. differs from its congeners by the presence of three subgenital setae in males and none in females, 41–44 perigenital setae and two posterior external genital acetabula in males. Acarochelopodia caissara sp. nov. has a rounded anterior epimeral plate margin, the posterior epimeral plates are partially divided into two halves but anteriorly joined by a narrow band, the dorsal setae on tarsus I are grouped 1:2, and the anterior and posterior dorsal plates have a length: width ratio of 1.61–1.77 and 1.60–1.70, respectively.

Notes on Kaszabjbaloghia with the description of a new species from Ecuador (Acari: Mesostigmata: Uropodidae)

Kaszabjbaloghia Hirschmann, 1973, distributed in South-America, is characterized by the following combination of characters: reduced marginal shield, posteromarginal setae placed on membranous cuticle on the dorsal idiosoma, linguliform genital shield in females, oval or egg-like genital shield bearing one pair needle-like setae in males, and the characteristic shape of peritremes. In this contribution, I provide short redescriptions of the known species of Kaszabjbaloghia and describe a new species, K. ecuadorica sp. nov., from Ecuador. The new species is similar to K. kaszabi Hirschmann, 1973, but differs from the latter in the ornamentation of genital shield of the female and the number of sternal cavities. Additionally, we transfer K. hirschmanni Hiramatsu, 1978 to Hutufeideria Hirschmann & Hirmatsu, 1977 (as Hutufeideria hirschmanni (Hiramatsu, 1978) comb. nov.) on the basis of the following: setation of dorsal shield, ornamentation of caudal part of the dorsal shield, shape of hypostomal setae, shape of internal malae and setation of the palp. An identification key to the species of Kaszabjbaloghia is also provided. Original illustrations and scanning micrographs are provided for all species.

Studies on contact sex pheromones of the caridean shrimp Palaemonetes pugio: II. The role of glucosamine in mate recognition

The role of surface glycoproteins in mate recognition of the shrimp Palaemonetes pugio was studied using mating bioassays and fluorescence microscopy. Our data indicate that a glycoprotein associated with female shrimp functions in mate recognition in P. pugio. This glycoprotein is likely to be a glucosamine or an N-acetylglucosamine-containing glycoprotein complemented by a lectinlike receptor on males. Significantly fewer copulations occurred in seawater augmented with glucosamine as compared to seawater augmented with glucose. Thus, it is likely that glucosamine competitively inhibits mate recognition by binding male receptors and significantly reducing recognition of parturial females. The antennal lagellum of decapod crustaceans has long been considered to be chemotactile with bimodal, touch/taste receptors. The fluorescent dye, Lucifer Yellow, is incorporated into antennal setae from the surrounding seawater. Furthermore, the fluorescent dye, DiI, stained neural tissues at the base of the antennal setae. Taken together, these results are consistent with a bimodal, sensory function. When fluo-treated male antennal setae were exposed to the carapace of postmolt, parturial females, an immediate and significant increase in fluorescence intensity was observed, suggesting that Ca2+ likely acts as a second messenger for the receptor system. Fluo-labeled antennal setae of both males and females showed larger increases in intracellular Ca2+ levels when exposed to glucosamine as compared to glucose. The effects produced by glucosamine were sexually dimorphic, with male setae displaying a significantly greater mean overall change in fluorescence intensity than female setae. The dimorphic response observed suggests that glucosamine or a related compound serves as a female signal (i.e., contact sex pheromone) in mate recognition.

Morphological and molecular comparison of host‐derived populations of parasitic Psoroptes mites

Infestation by parasitic Psoroptes mites (Acari: Psoroptidae) is an important cause of economic loss and welfare problems in livestock in many areas of the world. At least five species within this genus have been recognized, based on the host infested, the infestation site and differences in length of the opisthosomal setae of adult male mites. Here the integrity of these species is considered by subjecting populations of mites from a range of host species and geographical locations to simultaneous morphological and molecular genetic analyses. Morphological analysis showed that there were significant differences in shape and size between mite populations from different hosts, and that length of the outer opisthosomal setae in males and the homologous seta in females were the most important distinguishing character in adults. However, considerable variation in outer opisthosomal seta length was evident within and between populations of mites, and differences were not clearly related to host-species or geographical origin and did not support the accepted species differences. Molecular characterization using sequence data from the mitochondrial second internal transcribed spacer (ITS-2) region and microsatellite markers found little or no consistent host-related variation between the mite population samples. The results suggest that there is no case for considering the Psoroptes mites from the different hosts examined as separate species and that the morphological variation observed therefore may represent phenotypic adaptation to the local microenvironment on particular species of host.

Glochinema bathyperuvensis sp. n. (Nematoda, Epsilonematidae): A new species from Peruvian bathyal sediments, SE Pacific Ocean

Glochinema bathyperuvensis sp. n., the first record of Epsilonematidae from bathyal muddy sediments of the oxygen minimum zone (OMZ) off Callao, Peru (eastern Pacific Ocean) is described. The new species belongs to the subfamily Glochinematinae and is characterized by the possession of more than 8 pairs of subdorsal thorns asymmetrically arranged and a single dorsal one in the pharyngeal region, as well as by the presence of ten to thirteen blade-like cuticular protrusions forming a latero-dorsal palisade around the posterior head region and anterior cervical region. In addition, G. bathyperuvensis is characterized by its large size, more than 240 cuticular annules, provided with an extremely dense „hairy“ body ornamentation and, four rows of ambulatory setae: two inner subventral ones with 8 to 9 setae in males, and 5 to 6 setae in females, and two outer subventral rows composed each of 9-12 ambulatory setae followed by a large number of modified somatic setae. The dense hairy body spines, the large number of modified somatic setae, its dominant occurrence exclusive in oxygen-depleted, organic-rich soupy surface sediments indicate an adaptation to the stressed OMZ habitat conditions.

A new canestriniid mite, Bircericola bertrami n. g., n. sp. (Acari: Astigmata: Canestriniidae), parasitic on tenebrioniid beetles (Coleoptera: Tenebrionidae) from Tunisia.

The new genus Bircericola (Acari: Astigmata: Canestriniidae) and new species Bircericola bertrami from undetermined tenebrioniid beetles from Tunisia are described. Diagnostic features include: dorsal integument covered by longitudinal lines; suture separating propodosoma from hysterosoma present; male adanal suckers well developed; two pairs of paranal setae in males and six pairs in females; tarsi I-II very short (< 30 microm); and solenidia delta I and delta II subequal in length to setae cG I and cG II, respectively.

Experimental Analysis of Adhesion Of Chrysolina Polita (Chrysomelidae: Coleoptera) On A Variety of Surfaces

ABSTRACT Pulling forces of Chrysolina polita (L.) on glass, perspex and cloth have been recorded and are plotted against body weight. The additional weight of eggs in many of the females is probably the main reason that, in females, pulling forces do. not increase significantly with body weight, whereas those of males do. Pulling forces on glass and perspex are significantly correlated but, in general, neither are significantly correlated with those on cloth. This is because traction on glass and perspex is achieved by the adhesive setae, and on cloth by the tarsal claws. Counts of the adhesive setae in 14 individuals indicate that numbers of climbing setae in females and males and females (combined), male setae in males, and the total number of adhesive setae in males, all show a significant increase with body weight. Pulling force increases with the total number of adhesive setae in females, and males and females (combined). Multiple regression analysis confirms the view that pulling force is a function of the number of adhesive setae. Hooks, suction, electrostatic forces and seizure are largely discredited, and molecular adhesion between the setae and the substratum, and possibly the cohesive forces and surface tension of a thin fluid layer, are confirmed as the most likely modes of adhesion on smooth surfaces in C. polita and most beetles. It is proposed that the main forces of detachment acting on a leaf beetle are probably drag and the whiplash effect of the leaves and branches. Estimates for the wind speeds required to remove beetles from glass and cloth by drag forces alone are calculated.