A new species of Notodiaptomus Kiefer, 1936 (Copepoda,Diaptomidae) from the Amazon and Orinoco River Basins

A new species of Notodiaptomus, Notodiaptomus simillimus sp. nov., based on the female originally but erroneously assigned to Rhacodiaptomus calatus, and the corresponding newly discovered male, is described and illustrated in detail. The designation of the female as a new species of Notodiaptomus, and the recognition of the corresponding new male, is based on detailed morphological and biometrical studies, analysis of the known distribution and material from laboratory cultures. Morphological analysis demonstrated that the female shares the form of the external genital area and setal armature of the exopod 2 of leg 5 with other species of Notodiaptomus but they differ from those exhibited by species of Rhacodiaptomus. The distributions of the female and male assigned to Notodiaptomus simillimus sp. nov. overlap and include the Atabapo and Guaviare Rivers and Lago Calado. On the other hand, the distributions of the males and females originally assigned to R. calatus are disjunct and where they overlap, that is, in Lago Calado, each is accompanied by its respective mate. Laboratory cultures showed that, as expected, copulation did not occur between males and females described originally as R. calatus. This experiment demonstrated the existence of reproductive isolating mechanisms between these females and males, and confirmed the existence of two distinct genetic pools, i.e. two different species, the original males being of the valid R. calatus and the female a new Notodiaptomus. This female and the corresponding newly discovered male are N. simillimus. The new species is closely related to N. coniferoides.     

Requirement ofwingless signaling andengrailed action in the development and differentiation of reproductive system inDrosophila

The segment polarity geneswingless (wg) andengrailed (en) have been shown to play important roles in pattern formation at different stages ofDrosophila development in the thoracic imaginai discs. We have studied the patterns of expression of these genes in genital discs from wild type larvae, pupae and pharate adults and also from hetero-allelic mutant combinations of these genes. Our results suggest that these genes play vital roles in the normal development and differentiation of genital discs and gonads. In the absence of normalwg oren functions, the flies showed a complete lack of internal accessory reproductive organs and specific defects in the external genitalia. In addition, the testes in such males were small, rounded and with an abnormal cellular organization, although the ovaries in females appeared normal. Temperature shift experiments using the conditional mutant allele ofwg, (wg ^IL-114 ) indicated a requirement ofwg signaling from second instar onwards for normal development and differentiation of the accessory reproductive organs. Using a heat-shock allele (Hs-wg) we also show that the spatially regulated expression ofwg as a pre-requisite for normal development and differentiation. Based on the expression patterns ofen andhedgehog (hh) we suggest that even in the genital disc development and differentiation the action ofen is mediated throughhh.     

Partial hyperploidy of the X-chromosome inDrosophila hydei leading to duplication of male gonadal and genital structures

Summary Introduction of two doses of the X-chromosomalw ^mCo duplication next to a normal X-chromosome in males ofD. hydei leads to duplication of testis tissue and structures derived from the male genital disc. The effect of this partial hyperploidy of the X-chromosome seems restricted to the male. We tentatively conclude that this part of the X-chromosome contains some factor(s) which may specifically affect the reproductive system and analia of males.     

The function of the caudal keel inPercina (Percidae)

Synopsis Unique to darters of the subgenusOdontopholis ofPercina andPercina (Imostoma)antesella is the development of a caudal keel in breeding males. The keel is a semicircular extension of the ventral surface of the caudal peduncle and anterior lower caudal fin. The reproductive behavior of species ofPercina implies an adaptive function related to the burial and fertilization of eggs. The caudal keel appears to serve as a plow-share which, in conjunction with an elongated anal fin, facilitates the transfer of sperm from the male's genital opening to eggs buried in the substrate by the female.     

Gradual acquisition of the developmental capacity to differentiate adult structures by the genital disc of Drosophila melanogaster

Summary Diplo-X flies homozygous for the transform-er-2 ^ts (tra-2 ^ts) mutation develop into females at 16° C, while they develop into males at 29° C (Belote and Baker 1982). By means of this conditional mutation, we have carried out a detailed analysis of the development of the genital disc. Temperature shifts between 16 and 29° C, in both directions, and temperature pulses at 29° C, have been applied during the larval growth of tra-2 ^ts homozygous diplo-X flies, and the external derivatives of the genital disc have been analysed. Genital discs shifted from 16 to 29° C rapidly lose their capacity to differentiate female genital structures, while they become able to differentiate male genital structures whose inventory is more complete the earlier in larval development the temperature shift is carried out; moreover, duplicated male genital structures were observed. In the shift from 29 to 16° C, the genital disc loses its capacity to differentiate male genital structures, while it becomes able to differentiate female genital structures. The inventory of male structures is smaller, and the inventory of the female structures is more complete, the earlier in larval development the temperature is shifted. No duplicated female or male genital structures were observed in the downshift experiment. With respect to the analia, the shift from 16 to 29° C resulted in the quick formation of pure male anal plates, while in the opposite shift the formation of pure female anal plates occurred gradually. Moreover, the time course for the dorsal and ventral anal plates to show normal female phenotype was different: when the dorsal anal plates were completely normal, it was still possible to find incomplete ventral anal plates. In the pulse experiment at 29° C, the genital disc is able to differentiate both female and male genital structures, although the inventory of the latter ones was not complete. In addition, the capacity of the genital disc to differentiate male genital structures depended on the duration of the temperature pulse. The anal plates were always female, although they showed a reduction in their size, the ventral female anal plate being more affected than the dorsal one. No male anal plates were observed. The results have revealed that the genital disc follows a sequence in its capacity to differentiate female or male adult structures. We suggest that this sequence reflects the sequence of determination events occurring in the genital disc during its larval growth. In addition, results shown here provide evidence for the existence in the female genital primordium of a set of cells capable of giving rise either to female genital structures (ventral vaginal plates) or to male genital structures (hypandrium and penis apparatus). We also present evidence supporting the previous idea of two primordia for the anal plates.     

Cell lineage restrictions in the genital disc ofDrosophila revealed byMinute gynandromorphs

Summary The genital imaginal disc ofDrosophila differentiates the terminalia, i.e. the genitalia and analia, of both sexes. It represents a composite anlage, containing a female genital primordium, a male genital primordium and an anal primordium. In normal males and females, only one of the two genital primordia differentiates; the other is developmentally repressed. Therefore, cell-lineage relationships between the male and female genital primordia can only be studied in sexual mosaics which differentiate female and male cells. We producedMinute (M)non-Minute(M⁺) gynandromorphs and selected those with sexually mosaic terminalia for a cell-lineage analysis. In these mosaics, either the male (XO) or female (XX) cells wereM ⁺ and thus had a growth advantage. The differential growth rates served as a tool to detect clonal restrictions. In control gynandromorphs (M ⁺M ⁺), the amount of female genitalia differentiated was largely independent of the amount of male genitalia present. In contrast, male and female anal structures, as a rule, added up to one full set. The same was true for the experimentalMM ⁺ gynandromorphs, but the contribution ofXX andXO cells to mosaic terminalia changed drastically due toM ⁺ cells competing successfully against the more slowly growingM cells. Specific subsamples ofMM ⁺ gynandromorphs showed thatM cells in a non-mosaic primordium are shielded from cell competition taking place in the neighbouring mosaic primordium. We conclude that the three primordia of the genital disc represent developmental compartments. In the genital primordia, even developmentally repressedM ⁺ cells compete successfully against developmentally activeM cells.     

Spermatophore transfer in Euchaeta species in a 2000 m water column

The numbers and placement of spermatophores transferred by males to females in the genus Euchaeta are examined in the northeastern Atlantic Ocean. Multiple placement of spermatophores is present in the five diel, vertically migrating species, E. acuta, E. pseudotonsa, E. gracilis, E. norvegica and E. hanseni. Direct placement covering the genital opening is usually, but not always the primary placement site. Males produce two sizes of spermatophores corresponding to the small directly placed and the large indirectly placed ones attached to the females. Females of the other species, E. barbata, E. barbata f. farrani, E. scotti, E. bisinuata, E. sarsi, E. abbreviata, E. longissima and E. bradyi, all meso- or bathypelagic non-vertically migrating species, have a single spermatophore attached to the genital opening. Spermatophore size is related to male and female prosome lengths and to the depth at which the species lives. Size variation of spermatophores within species decreases with increasing depth. Spermatophore transfer in deep-sea species, a single spermatophore directly placed, appears to be more efficient than in the epipelagic and mesopelagic vertical migrators where multiple placement involves a proportion of spermatophores with no direct connection to the genital opening.     

Exaggerated male genitalia intensify interspecific reproductive interference by damaging heterospecific female genitalia

Male–male competition over fertilization can select for harmful male genital structures that reduce the fitness of their mates, if the structures increase the male's fertilization success. During secondary contact between two allopatrically formed, closely related species, harmful male genitalia may also reduce the fitness of heterospecific females given interspecific copulation. We performed a laboratory experiment to determine whether the extent of genital spine exaggeration in Callosobruchus chinensis males affects the fitness of C. maculatus females by injuring their reproductive organs. We found that males with more exaggerated genital spines were more likely to injure the females via interspecific copulation and that the genital injury translated into fecundity loss. Thus, as predicted, reproductive interference by C. chinensis males on C. maculatus females is mediated by exaggeration of the genital spine, which is the evolutionary consequence of intraspecific male–male competition. Harmful male traits, such as genital spines, might generally affect the extent of interaction between closely related species.     

Genetic structure of Halotydeus destructor and Penthaleus major populations in Victoria (Acari: Penthaleidae)

The redlegged earth mite (Halotydeus destructor) and the blue oat mite (Penthaleus major) are major pests of pastures and crops in southern Australia. Reproductive modes, migration rates and levels of differentiation between populations were investigated using allozyme electrophoresis. Collections were made throughout Victoria and a sample was also obtained from Western Australia. Three enzyme loci were polymorphic in H. destructor (Mdh-1, Mdh-2 and Idh). Genotype frequencies of these loci did not differ between phenotypic males and females, providing no evidence for haplodiploidy. Allele frequencies were in Hardy-Weinberg equilibrium, indicating that H. destructor is diploid and sexual. This was confirmed via crosses between males and females. Allele frequencies differed between Victorian sites, although F statistics indicated little differentiation over all loci. A sample from Western Australia did not differ in allele frequencies from the Victorian sites. Four polymorphic loci were found in P. major (Mdh-1, Mdh-2, Idh and Gpi). Only a few multilocus genotypes occurred in a sample, indicating that P. major is parthenogenic. No male P. major were found in this study. A number of colour morphs were also identified and a genetic association between genital plate colour and clonal type was found in one population of P. major. Two different body colour morphs were associated with different clonal types.     

Context and Development of Sexual Behavior of Wild Bonobos (Pan paniscus) at Wamba, Zaire

I studied sexual behavior of immature bonobos (Pan paniscus) in a wild group living at Wamba, Zaire, with special reference to its development. Even immature individuals under 1 year old performed sexual behavior. Sexual behavior occurred in almost all age–sex combinations, except between immature and mature females. Based on analyses of behavioral pattern and context, I classified sexual behavior involving immature individuals into three categories. (1) Genital contact between immature individuals was observed during play, and was performed by males more frequently than by females. This sexual behavior shared many traits with that of other great apes. (2) Copulation-like genital contact was observed between immature males and mature females. Its frequency increased with the immature male's age; it developed into copulation in adulthood. (3) Genital contact used to regulate interindividual relationships. This behavior, which is unique to bonobos, was absent among infants. It developed between late juvenile and early adolescent periods in association with changes in social circumstances.     

On Gaussia Wolfenden (Copepoda,Calanoida, Metridinidae)

Aspects of the female genital segment with and without attached couplers and enclosed spermatophores are studied of Gaussia specimens collected in the SW Atlantic and SE Pacific. A new species found in the SW Atlantic, Gaussia asymmetrica, is proposed.     

Courtship behavior of the mosquitoSabethes cyaneus (Diptera: Culicidae)

Unlike any other mosquito reported, Sabethes cyaneus(Fabricius) displays an elaborate courtship before and during copulation. A male approaches a female suspended from a horizontal stick, suspends himself in front of her as he grasps her folded wings, and proceeds with a series of discrete stereotyped behaviors that involve proboscis vibration and movement of iridescent blue paddles on his midlegs. The sequence of these behaviors is as follows: freeleg waving, swinging, copulation attempt, superficial coupling, waving, genital shift, waggling, and release. Insemination occurs after genital shift. The only overt reciprocation by the female is abdomen lowering during the male's swinging. Courtship is often unsuccessful, and males are usually rejected during freeleg waving. The relation between male performance and mating success remains obscure.     

Courtship behavior and discrimination between potential mates by maleDelia antiqua (Diptera: Anthomyiidae)

The repertoire of courtship behaviors of male onion maggots,Delia antiqua (Meigen), in a laboratory bioassay chamber, was analyzed by direct observation and by video recordings, in conjunction with a multichannel event recorder. Seven courtship behaviors were categorized: inspection from the substrate, aerial inspection, contact from the substrate, contact from the air, genital alignment, copulation, and male-male interaction. The frequency distribution of copulation bouts was best described by a Poisson distribution; peak mating activity occurred about 1 h into the bioassay. The duration in copulo, however, was extremely variable. On average, males spent 30 sin copulo (n=183); <30% of bouts were >50 s. The ability of males to discriminate between sexes, sexually immature and mature females, and between females ofD. antiqua and the cabbage maggot,Delia radicum (L.), was most pronounced in the elements of genital alignment and attempted copulation. The courtship and mating behavior inD. antiqua is consistent with a sequence that relies initially primarily on indiscriminate visual recognition of a potential mate, followed by species-and sex-specific semiochemical recognition upon contact.     

Differential gene-expression patterns in genital fibroblasts of normal males and 46,XY females with androgen insensitivity syndrome: evidence for early programming involving the androgen receptor

Background  

Androgen insensitivity syndrome (AIS) comprises a range of phenotypes from male infertility to complete feminization. Most individuals with AIS carry germline mutations of the androgen receptor (AR) that interfere with or ablate its function. As genital fibroblasts retain expression of the AR in vitro, we used genital skin fibroblasts from normal males and 46,XY females with complete AIS due to known AR mutations to gain insights into the role of the AR in human genital differentiation.     

Precopulation Sexual Selection in Nysius huttoni White (Heteroptera: Lygaeidae) in Relation to Morphometric Traits

Nysius huttoni White is a polygamous bug, endemic to New Zealand, and an important pest of wheat and brassicas. This bug has a female-biased sexual size dimorphism but relative to body length, males have longer antennae, suggesting that the allometric scales of antennal–body relationships may be highly selective in sexual selection. Body weight and most morphometric traits measured have no effect on mating success of either sex. Males significantly preferred mating with females having thicker abdomens, more mature eggs, and longer ovipositors. This result suggests that males may select their mates on the basis of immediate reproductive benefit: fertilizing more eggs and ensuring better survival of these eggs. Males with large genital structures have mating advantages over those with small ones, suggesting that precopulation sexual selection in this species act on male genital traits rather than body weight and nonsexual traits. Finally, females significantly preferred males with greater slopes for the antennal-body relationship for mating. The allometry in the male antennal length may be an indicator of male reproductive fitness.     

A new stomach worm,Obeliscoides pentalagi n. sp. (Nematoda; Trichostrongyloidea) of Ryukyu rabbits,Pentalagus furnessi (Stone, 1900)

Summary A new trichostrongylid nematode, Obeliscoides pentalagi n. sp., from the stomach of the Ryukyu Rabbit, Pentalagus furnessi, collected on Amami-ohshima Island, south Japan is described. O. pentalagi n. sp. resembles O. leporis Schulz, 1931 and O. travassosi Liu & Wu, 1941, but differs in the relative size and morphology of the dorsal ray and genital cone of the males. The number and distribution of longitudinal cuticular ridges of O. pentalagi n. sp. is similar to those of O. cuniculi multistriatus Measures & Anderson, 1983, but it differs in the morphology of the spicules, dorsal ray and genital cone in males, and in the morphology of the prevulval lobe of the females. The discovery of O. pentalagi further supports the hypothesis of a Eurasian origin of the genus Obeliscoides (Graybill, 1923) Graybill, 1924 (Durette-Desset, 1983; Durette-Desset & Chabaud, 1977; Measures & Anderson, 1983a, b, c, 1984). The number and distribution of longitudinal cuticular ridges and variation of the prevulval lobe in females of O. leporis Schulz, 1931 are also examined and compared with those of other species.     

The Genus Obelus Hartmann, 1842 (Gastropoda, Pulmonata, Helicoidea) and its Phylogenetic Relationships

The genus Obelus, so far known from shells only, is re-described on the basis of the anatomy of its genital system. Its range is here restricted to north-western Africa and the Canary Islands. Four species are traditionally listed for the Canary Islands: Obelus despreauxii, O. moderatus, O. mirandae and O. cyclodon. The presence of the last species on the Canary Islands is doubtful, whereas the fossil/subfossil presence of O. pumilio is documented. The species Helix morata also belongs to the genus, as well as a new species, O. discogranulatus sp. nov. The genital systems of all confirmed extant Canarian species are shown. Obelus has a peculiar vaginal stimulator appendix (“appendicula”) which is homologous to the penial appendix of the Orthurethra and to the stimulatory organ of other Stylommatophora, with the exception that the A₃ portion is missing. The genus is diagnosed by characters of the vaginal stimulator appendix, such as a curved, finger-like A₂ portion of the appendicula ending proximally in a blind, well-developed muscular sac, and by the slender tubular A₄ portion arising laterally from the muscular sac duct. We conclude that Obelus belongs to the Cochlicella group because it shares an appendicula with the other genera of the group. However, it differs in anatomical details of this structure. The Cochlicella group should be recognized as a separate family Cochlicellidae Schileyko, 1972, with close relationships to the Helicellidae and the Hygromiidae. A new diagnosis for Cochlicellidae is proposed and its phylogenetic relationships are discussed.This is: Notes on the Malacofauna of the Canary Islands, No. 46.     

The first record of two demersal calanoid copepods,Pseudodiaptomus poplesia and P. nihonkaiensis in Korea,with remarks on morphology of the genital area

The demersal calanoid copepods Pseudodiaptomus nihonkaiensis Hirakawa, 1983 and P. poplesia (Shen, 1955) are redescribed from Korean waters. Using scanning electron microscopy, we examine the morphology of the female genital systems of four species of Pseudodiaptomus (P. inopinus, P. marinus, P. nihonkaiensis and P. poplesia), revealing interspecific differences. The zoogeography of these four species is discussed.     

Genital morphology of female goblin spiders (Arachnida: Araneae: Oonopidae) with functional implications

Spider genital morphology usually provides the best characters for taxonomy. Furthermore, functional genital morphology helps to understand the evolution of complex genitalia and their role in the context of sexual selection. The genital systems of most haplogyne spider families are poorly investigated with respect to their morphology. The present study investigates the female genitalia of the oonopids Oonops pulcher, Oonopinus kilikus, and Pseudotriaeris sp. by means of light microscopy and SEM. The male palps are briefly described. Females of O. pulcher store spermatozoa in an anterior and a posterior receptaculum (PRe). The genitalia resemble the primitive dysderoid genitalia supporting the hypothesis that the subfamily Oonopinae contains more basal oonopids. In O. kilikus, the anterior receptaculum is reduced to a sclerite. Spermatozoa are stored in a PRe. The receptacula of Pseudotriaeris sp. are reduced to sclerites. Spermatozoa in the uterus internus indicate that fertilization happens there or in the ovary. The anterior sclerite might serve females to lock the uterus during copulation as suggested for other gamasomorphines. The male palp of O. kilikus is simple, whereas the palps of O. pulcher and Pseudotriaeris sp. appear more complex. Complicated structures on the palp of Pseudotriaeris sp. indicate that males exert copulatory courtship.     

A reappraisal of the genus Phyllodiaptomus Kiefer, 1936, with the description of P. wellekensae n.sp. from India,and a redescription of P. tunguidus Shen & Tai, 1964 from China (Copepoda,Calanoida)

Phyllodiaptomus wellekensae n. sp. is described from south India. In the female, the genital somite is dilated at the left proximal margin and armed with an extraordinarily large, somewhat curved, laterally-directed spine; the right genital spine is much smaller than the left one. The terminal claw of leg 5 has a secretory pore at its tip and a characteristic conveyor canal on its anterior surface. In the right male P5, the coxal plate is short and unique in shape. The basis is 1.3 times as long as wide, with a long, sinuous, hyaline lamella on its medial margin. The first exopodite segment is short and optuse at its outer distal corner. The second segment is rectangular and has a short, hyaline, spinous projection between the lateral spine and the terminal claw. The left P5 has a large, serrate, hyaline fan between its apical thumb and medial apical seta. P. tunguidus is redescribed based on material newly collected from three localities in China.