Trophic strategies and functional morphology of feeding appendages, with emphasis on setae, of Upogebia omissa and Pomatogebia operculata (Decapoda: Thalassinidea: Upogebiidae)

Although species of Upogebiidae historically have been considered filter feeders, recent studies show that many species of this group also deposit feed. In this study, the degrees of trophic specialization of two species of this family, Upogebia omissa and Pomatogebia operculata , were analysed. Feeding mechanisms, stomach contents and morphology of the feeding appendages, with emphasis on setae, were examined. U. omissa , found in sandy substrate, is a generalistic feeder while P. operculata inhabits burrows inside corals, being more specialized in filter feeding. Only 21% of the 57 setal types described were common to both species. Setal types were clustered in three main categories: plumed, serrate and plumodenticulate. No simple setae were found. P. operculata has lower setal diversity, with higher ratio of plumodenticulate to serrate setal types than U. omissa. The 1st and 2nd pereiopods have an important role in collecting food. The mouthparts have two main functions: to brush and retain particles so that food can be transported from the pereiopods to the mouth. Generally in these appendages, the dactyli and basal endites are responsible for brushing particles and the meri and coxal endites for particle retention. The diversity of setal types and complexity of their distribution on the appendages may be related to the necessity to select and triturate particles prior to ingestion, reflecting the differences in trophic strategies utilized by U. omissa and P. operculata. Setal characters appear to be indicators of the relative importance of a specific feeding mode for species of this group.     

Système Sétifère des Maxillipèdes des Gonodactyloidea (Crustacea, Stomatopoda)

Analysis of the setal system was conducted on the maxillipeds of Gonodactyloidea, which includes the smashers, a functional group of stomatopods. Generally, the homogeneity of the setal system is demonstrated in stomatopods. However, examination of maxillipeds of Gonodactyloidea reveals that some setal types are systematic characters at levels of families or species. The smashers group has a very homogeneous setal system in three families: Gonodactylidae, Odontodactylidae and Protosquillidae. The setal analysis of maxillipeds confirms the functional role of these appendages. Like other morphological characters, the setal system of stomatopods has co-evolved with behavioral patterns in both groups: spearers and smashers.     

Is the Setal Patch on the Chelae of Hemigrapsus takanoi and Hemigrapsus sinensis (Crustacea,Brachyura, Varunidae) Advantageous in Fighting and Mating?

Many animals have unique morphological characters that function in social behavior. Sexual selection can affect the expression of such traits in males and females, leading to sexual dimorphism. We investigated the social function of setal patches on the chelae of two species of varunid crabs, one in which males, but not females, have setal patches (Hemigrapsus takanoi), and one in which both sexes have setal patches (Hemigrapsus sinensis). We experimentally removed setal patches and compared fighting and mating behavior of individuals with and without setal patches. In H. sinensis, males with setal patches removed were inferior fighters compared to intact males. In male H. takanoi and female H. sinensis, setal removal did not influence the outcome of fights. In mating, males lacking setal patches had a similar ability to copulate with females as intact males in both species. However, male H. takanoi with their setae removed tended to take more time to initiate copulation than did intact males. When females were given the opportunity to choose intact males or males without setal patches, females of H. takanoi did not discriminate between the two. Female H. sinensis, however, copulated with intact males more frequently compared to males lacking setal patches. Male H. sinensis showed no preferences for the presence of setal patches or the body size of females. Thus, our results indicate that setal patches have a social function in male H. takanoi and male H. sinensis, but not in female H. sinensis, suggesting that the setal patches of male crabs are a sexually selected trait in both species. However, the social function of male setal patches was more prominent in the species in which both sexes possess setal patches than in the species in which only males bear setal patches.     

Achaeta neotropica Cernosvitov and A. iridescens sp.n. (Oligochaeta, Enchytraeidae) from Serra do Mar, Sāo Paulo, Brazil

New material of Achaeta species was collected from a small portion of the tropical rain forest region of Brazil's east coast. For A. neotropica Cernosvitov, wider ranges of variation of several morphological characters are described and four varieties are recognized. Achaeta iridescens sp.n. differs from other species of the genus by the presence of intestinal pouches in segment VII. Both species are peculiar to Achaeta in that they have compact glandular masses surrounding the male pores and a more posterior origin of the dorsal vessel; they share with a few European and most non-European species the tendency to show a complete regression of some morphological characters, namely the setal follicles, oesophageal appendages and dorsal connection of the third pair of septal glands.     

Development of setal patterns in embryonic and adult aphids of the Hormaphidinae （Hemiptera： Aphididae）

The elementary traits and diversity of embryonic setal patterns of 31 species of 22 genera, in three tribes of Hormaphidinae are studied. The embryonic setal patterns to every species are provided. Based on the parsimony principle and the developmental principle, these patterns are analyzed in each tribe following the terminology of Richards （1965）. It is suggested that the setal patterns of abdominal tergites are the most important characters in embryonic and adult setal patterns. In conclusion, neoteny is a phylogenetic trend in the Hormaphidinae. Nipponaphidini and Hormaphidini have more typical neoteny in each genus and more diversity in different types of adult viviparous females than Cerataphidini, by showing more frequent and various protopatterns or mesopatterns.     

A morphometrical study of oribatid mites (Acari: Oribatida) of the genus Carabodes C.L. Koch, 1835 (Carabodidae) using a confocal laser scanning microscope: an alternative approach to quantitative analysis of various features

In the past, micro-arthropod taxonomists have mainly relied on qualitative characters to identify species, and relatively little attention has been paid to quantitative analysis. However, several taxonomic groups have high morphological variability, which creates problems in identification. Quantitative analysis of morphometrical data of specific characters could aid in understanding differences in the morphology of oribatid species. In this respect, confocal laser scanning microscopy and quantitative analysis were used to describe morphological traits of four oribatid mite species belonging to the genus Carabodes Koch, 1835—C. femoralis (Nicolet, 1855), C. labyrinthicus (Michael, 1879), C. ornatus Storkan, 1925 and C. subarcticus Trägårdh, 1902. All specimens were collected in Latvia. Thirteen morphological traits were measured for 838 adult individuals. The same traits were also measured with transmitted light microscopy, and results were compared. The impact of a number of environmental factors on traits was also assessed. High interspecific variability in size of most morphological features was observed. In many cases, sizes of the measured features correlated between different species. The ranges in length of notogastral setae p3 and h3 of C. femoralis did not overlap with those of C. labyrinthicus or C. ornatus. Significant correlations between body length and size of setal structures, as well as between setal structures, were detected. Size of morphological features was directly affected by the cover of lichens, a main food resource for Carabodes, and indirectly by the effect of soil moisture on lichen communities.     

中国Papirioides亚属一新种(弹尾目:齿(虫兆)科)(英文)

本文描述了锯(虫兆)属Papirioides亚属一新种,它具有夏威夷种P. serrata的许多特征,而与越南北部的P. aequituberculata最为相近。但该新种通过面部毛序具多种类型,大腹前部背面较多大毛和弹器齿节腹面的稳定毛序类型等主要特征与后者区分。包括本新种在内,目前已知国内有mirabilis(Denis)(福建),jacobsoni Folsom(台湾),yunnanus Itot(云南)等4种Papirioides亚属的弹尾目昆虫。     

A NEW SPECIES OF THE SUBGENUS PAPIRIOIDES FROM CHINA (COLLEMBOLA: DICYRTOMIDAE)

Abstract  A new species of the subgenus Ptenothrix (Papirioides) is described from Anhui Province, China. It shares many characters with the Hawaiian species serrata Snider and is most similar to the Asian species aequituberculata Stach from North Vietnam except its variable facial setal patterns, larger setae on anterior dorsum of great abdomen and constant setal pattern of ventral dens.     

Identification of immature tubificids (Oligochaeta) of Lake Constance and its influence on the evaluation of species distribution

In the course of an extensive taxonomical treatment of Oligochaetes collected from Lake Constance the immature specimens of all species were identified, mainly by setal characters. The method is presented, several hints are given and some characters of additional taxonomic value are described in a comparative way.The large extent to which evaluation of species distribution may be misleading if based only on the mature specimens is demonstrated.     

The structure and growth of the statocyst in the Australian crayfish Cherax destructor

The morphology of the statocyst of the Australian crayfish Cherax destructor was examined using scanning electron microscopy. It resembles in general structure, size, and position the statocysts of crayfish described previously, and the size and distribution of the fields of setae on the floor of the capsule are similar but not the same. Over the size range examined, the relationship between the carapace length, the length of the basal antennular segment, the diameter of the statocyst capsule, and the total number of setae are all linear. The number and position of setae on the floor of the statocyst capsule were mapped for animals in two size classes (small, ca. 20 mm; large, ca. 50 mm) to test for changes in their arrangement during growth. The change in the ratio of setal number to statocyst size between the two size classes was about three times greater for the anterior setal field than for the other fields. We propose that differential development of the setal fields may be related to changes in the force-monitoring requirements of the animals as they increase in size, but this remains to be experimentally tested.     

Neotropical Copestylum (Diptera,Syrphidae) breeding in Agavaceae and Cactaceae including seven new species

We studied 42 species of saprophagous, Neotropical Copestylum (Diptera, Syrphidae) reared from decaying Cactaceae and Agavaceae. Thirty‐three species were reared during fieldwork in Bolivia, Costa Rica, Ecuador, Mexico, Peru, and Trinidad from 1998–2007. Nine species came from museum and private collections. Seven were new species. We describe these new species and the third stage larva and/or puparium and breeding sites of 40 species. Not described are two apparent species related to Copestylum apicale (Loew, 1866) reared from Cactaceae. Resolution of their status was beyond the scope of this paper but reference is made to their distinctive larval morphology. Based on early stage characters all reared species can be placed in ten species groups, all but three of which have been recognized previously on the basis of adult characters. A high level of congruence was found between adult and larval characters in terms of these species groups. Eight of the groups appear to be related closely and may represent a monophyletic lineage within Copestylum that has diversified in xeric habitats. Early stage morphology varied within and amongst groups but two trends in functional morphology are recognizable. One trend is towards feeding in watery decay and the other towards feeding in firmer decay. The latter trend is characterized by species that scoop food and use grinding mills in their head skeletons to break it up. They also have armoured thoraces with varying arrangements of sclerotized spicules or stiffened setae for gripping and protection during tunnelling, a short anal segment, and a short posterior breathing tube for protecting the openings. The former trend is characterized by species with opposite and contrasting features. They filter food and have well‐developed pre‐oral setal filters but they lack grinding mills or only have poorly developed grinding mills. They have reduced thoracic armature, elongate anal segments, and posterior breathing tubes which facilitates simultaneous feeding and respiration. Comparison with 23 Copestylum species reared from bromeliads (Bromeliaceae) suggests a common pattern of diversification in that species groups with the largest body sizes are more specialized.     

The question of fluctuating asymmetry in the blacklegged tick Ixodes scapularis (Acari: Ixodidae)

An analysis of fluctuating asymmetry was conducted on populations of the blacklegged tick Ixodes scapularis. The eight groups used in this study consisted of larvae and nymphs and males and females from the states of Minnesota, Massachusetts, Maryland, Missouri, North Carolina and Georgia and the F1 progenies of reciprocal crosses between ticks from Massachusetts and Georgia. Measurements included 16 larval, 19 nymphal, ten female and 12 male bilateral characters. Only five differences between the right and left bilateral characters had normal distributions with means of zero and differences in variances between the groups. These five characters included three setal lengths of the larvae, the spiracular plate length of females and the coxa I internal spur widths of males. Bivariate plots of character size ((R+L)/2) and asymmetry (R-L) showed no correlation. In the spiracular plate lengths of females and one of the setal lengths, ticks from Massachusetts had significantly less within-group variance than all the other groups. The only character in which fluctuating asymmetry was observed was the coxa I internal spur width of males, in which ticks from Minnesota, Missouri and North Carolina had significantly greater variance than the remaining groups; fluctuating asymmetry in this character may be explained by sexual selection. The cross progeny did not demonstrate any fluctuating asymmetry, as would be expected if the northern and southern forms of I. scapularis were true species. The virtual lack of fluctuating asymmetry in the characters used in this study further supports the conclusions of other studies which concluded that I. scapularis is a species with clinal variation and a broad geographic distribution.     

Flagellar setae of the second antennae in decapod shrimps: sexual dimorphism and possible role in detection of contact sex pheromones

Summary

The antenna 2 (antennal) flagella of decapod shrimps are chemotactile, and their setae are proposed as sensilla involved in recognition of females by males via a contact sex pheromone on the surface of the female. Male recognition of females receptive to mating occurs in many caridean species upon contact of male antennal flagella with the surface of a newly molted parturial female. The hypothesis of sexual dimorphism in the number and kind of setae on the antennal flagella of four caridean and one penaeid shrimp species was tested with setal counts and observations on setal morphology. Unique male antennal setae (“male-specific sensilla”) were not identified in any of the species investigated. However, the abundance of antennal setae was significantly greater in males than in breeding females in the palaemonid carideans Palemonetes pugio and Macrobrachium ohione. In the hippolytid caridean Thor manningi and alpheid caridean Alpheus normanni, no sexual dimorphism in setal abundance was demonstrated. In the penaeoid Rimapenaeus similis, males had a higher abundance of antennal setae than the larger breeding females but so did juvenile females, similar in size to males. The sexual dimorphism in antennal sensilla in the palaemonid species and its absence in A. normanni might be related to their different mating systems, but no such association is suggested for T. manningi and R. similis. Setal morphology suggestive of chemoreceptive function (a terminal pore) was observed in all species.     

Redescription of Grania monochaeta (Michaelsen), a Marine Enchytraeid (Oligochaeta) from South Georgia (SW Atlantic)

Enchytraeus monochaetus Michaelsen is redescribed as Grania monochaeta. It is distinguished from other Grania species by two main characters: its morphology of spermathecae, and its setal distribution, the latter being unique within the genus owing to the presence of dorsal setae in preclitellar segments.     

中国安徽省刺齿虫兆属一新种(弹属目:长角虫兆科)

本文记述刺齿虫兆属１新种：祁门刺齿虫兆Ｈｏｍ ｉｄｉａ ｑｉｍ ｅｎｅｎｓｉｓ, ｓｐ． ｎｏｖ． （图１～１２）。该种在颏部具有叶状毛与Ｈ． ｌａｔｉｆｏｌｉａ Ｌｉ＆ Ｃｈｅｎ １９９９和Ｈ． ｐｏｌｙｓｅｔａ Ｃｈｅｎ １９９８相似,主要区别在于体色斑纹和头部背面、下唇基部、颏部及第４腹节等部位毛序。正模♀,副模２♀♀,安徽祁门牯牛降国家自然保护区,１９９４－ Ⅷ－ ２５,存于南京大学生物科学与技术系。     

Morphology and chaetotaxy of the first instar larvae of six species of the Satyrus (s.l.) series (Lepidoptera: Nymphalidae)

Abstract. The morphology and chaetotaxy of the first instar larvae of six species belonging to the genera Hipparchia, Kanetisa and Chazara are described. Specific characters are stated, drawn mainly from size, setal length and morphology, and the shape of the suranal plate. Several characters, other than chaetotaxy, that are of potential use in nymphalid systematics are discussed. The larval chaetotaxy is briefly compared with that of both heliconiine and danaine first instar larvae.     

Variation in larval chaetotaxy in Orthosia gothica (Lepidoptera: Noctuidae): effects of mother,sex and side,and implications for systematics

Insect larval characteristics, including chaetotaxy, are used widely in systematics, including for classification and phylogenetic reconstruction. Despite their common use, basic aspects of larval morphology, including intraspecific variation, effects of relatedness between individuals, sex and asymmetry, are little investigated. In the larvae of the noctuid moth Orthosia gothica, properties of shape and size were separated to examine their effects separately. Siblings were found not to cover the entire variation of a population, and therefore specimens originating from a single female do not represent independent samples. This methodological bias may potentially lead to wrong conclusions regarding species characteristics. We observed slight differences between the left and right sides of the specimens studied, implying that one side should be examined consistently in studying larval chaetotaxy. We found no differences between sexes, but this may apply only to the species examined here; in general, sex should be determined and accounted for. We discovered considerable variation in seta numbers, which further emphasizes the importance of sufficient material, particularly in cladistic analyses in which setal counts are often used as characters.     

Morphology and distribution of antennular setae of scyllarid lobsters (Scyllarides aequinoctialis, S. latus, and S. nodifer) with comments on their possible function

Abstract. Lateral flagella of the antennules of scyllarid lobsters were examined for setal morphology and distribution via scanning electron microscopy. Setal distribution patterns were mapped directly for 3 regions of the antennule ( base, tuft , and tip ) and analyzed for differences: (1) between left and right antennules, (2) between males and females within a species, and (3) among species by comparing counts of setae per annulus in the ventral tuft region only. Six types of antennular setae were identified based on their external morphology: aesthetases, simple, modified simple, asymmetric, hemi-plumose, and toothbrush setae. These different types were organized in a clear pattern over the ventral and dorsal surfaces of the lateral flagella of the antennule. Aesthetase, asymmetric, modified simple, and hemi-plumose setae were found only on annuli in the tuft region between the distal and proximal ends of the flagellum. Simple setae were found on all annuli of all regions of the antennule, and toothbrush setae were mainly concentrated on all annuli of the base region and on proximal annuli of the tuft region . All species of scyllarids examined had the same general pattern of setal distribution and no differences were found between left and right, or male and female antennules. Similar setae located on the lateral antennules of species from the families Nephrophidae and Palinuridae (clawed and spiny lobsters) have been previously described as chemo- and/or mechanoreceptive for use in distance chemoreception (i.e., detection and orientation to olfactory stimuli). Based on work on clawed and spiny lobsters, we predict that the aesthetases on slipper lobsters have a chemoreceptive function and that simple and toothbrush setae may have a bimodal chemo- and mechanoreceptive function.