Copulatory Structures Research Articles

The phylogenetic relationships of Chalcosiinae (Lepidoptera, Zygaenoidea, Zygaenidae)

The chalcosiine zygaenid moths constitute one of the most striking groups within the lower-ditrysian Lepidoptera, with highly diverse mimetic patterns, chemical defence systems, scent organs, copulatory mechanisms, hostplant utilization and diapause biology, plus a very disjunctive biogeographical pattern. In this paper we focus on the genus-level phylogenetics of this subfamily. A cladistic study was performed using 414 morphological and biochemical characters obtained from 411 species belonging to 186 species-groups of 73 genera plus 21 outgroups. Phylogenetic analysis using maximum parsimony leads to the following conclusions: (1) neither the current concept of Zygaenidae nor that of Chalcosiinae is monophyletic; (2) the previously proposed sister-group relationship of Zygaeninae + Chalcosiinae is rejected in favour of the relationship (Zygaeninae + ((Callizygaeninae +Cleoda) + (Heteropan+ Chalcosiinae))); (3) except for the monobasic Aglaopini, none of the tribes sensuAlberti (1954) is monophyletic; (4) chalcosiine synapomorphies include structures of the chemical defence system, scent organs of adults and of the apodemal system of the male genitalia. A paired metathoracic androconial organ and a series of abdominal tergal corematal organs have been discovered, both being new to Lepidoptera. Due to highly homoplastic patterns in copulatory structures and wings that demonstrate significant sexual dimorphism, polymorphism and mimicry, 17 of the 69 ‘true’ chalcosiine genera (c. 25%) are shown to be either paraphyletic or polyphyletic. The present classification is therefore very misleading. Reductions of various parts of the male genitalia in some groups are accompanied by morphological and functional replacement involving the 8th abdominal segment. A prominent but convergent lock and key mechanism is revealed.

A secondary copulatory structure in a female insect: a clasp for a nuptial meal?

Secondary copulatory structures are well-known in male dragonflies and spiders. Here I report a secondary copulatory organ in female ground weta, Hemiandrus pallitarsis (Ensifera, Orthoptera - crickets and allies). The organ, located on the underside of the abdomen, appears to secure the male's genitalia during the transfer of a spermatophylax nuptial meal to this location, an area quite separate from the female's primary copulatory structures, where the sperm ampulla is attached.

Postembryonic expression of Caenorhabditis elegans mab-21 and its requirement in sensory ray differentiation.

The male tail sensory rays in Caenorhabditis elegans are complex copulatory structures, the normal patterning of which requires a number of regulatory genes. Among them, mab-21 specifies the identity of sensory ray 6. By using green fluorescent protein reporters, we identify multiple cis-acting elements that control the developmental expression of mab-21. Traced with a functional mab-21:gfp gene driven by authentic regulatory sequences, mab-21 expression could be detected in hypodermal, neuronal, muscle, and ray cells. We showed here that the expression of mab-21 in the hypodermis and neuronal cells was dispensable for its function in ray 6. In contrast, its expression in the ray 6 structural cell and neurons as conferred by its 3' enhancer was crucial for determining the correct ray 6 identity.

Argulus chicomendesi sp. n. (Crustacea: Argulidae) parasita de peixes da Amazônia brasileira

Uma nova espécie de Branchiura é descrita para o Brasil. Os espécimens foram coletados parasitando peixes da Amazônia brasileira. A nova espécie é caracterizada pela: coloração e desenhos da superfície dorsal da carapaça, tórax e abdômen; presença de espinhos em toda a margem externa da superfície ventral do abdômen (pléon); ornamentações das antenas, antênulas, maxilas, pernas, superfície ventral do corpo; forma e pigmentação das estruturas copulatórias acessórias do macho.

The LIN-29 Transcription Factor Is Required for Proper Morphogenesis of theCaenorhabditis elegansMale Tail

TheCaenorhabditis elegansgenelin-29encodes a zinc-finger transcription factor that is required for hypodermal cell terminal differentiation and proper vulva morphogenesis. Here we demonstrate thatlin-29is also required in males for productive mating. We show thatlin-29males can perform the early mating behaviors including response to hermaphrodite contact and vulva location, but they do not perform the subsequent steps of vulva attachment via spicule insertion and sperm transfer. Consistent with this observation, we found thatlin-29mutant spicules are on average 43% shorter than wild-type spicules while other male mating structures appear unaltered. Inlin-29mutants, spicule development goes awry after the generation of spicule cells, when spicule morphogenesis occurs in wild-type males. We show that LIN-29 accumulates in many cells of the wild-type male tail, including those that form the spicules. We demonstrate, through analysis of genetic mosaics, that the formation of wild-type-length spicules requireslin-29(+)in the AB.p lineage, the lineage that gives rise to the spicules and other male copulatory structures. Our mosaic analysis also reveals a role forlin-29(+)in the P1 lineage, which mainly produces sex muscles, cells of the somatic gonad, and body wall muscles.

A BMP homolog acts as a dose-dependent regulator of body size and male tail patterning inCaenorhabditis elegans

We cloned the dbl-1 gene, a C. elegans homolog of Drosophila decapentaplegic and vertebrate BMP genes. Loss-of-function mutations in dbl-1 cause markedly reduced body size and defective male copulatory structures. Conversely, dbl-1 overexpression causes markedly increased body size and partly complementary male tail phenotypes, indicating that DBL-1 acts as a dose-dependent regulator of these processes. Evidence from genetic interactions indicates that these effects are mediated by a Smad signaling pathway, for which DBL-1 is a previously unidentified ligand. Our study of the dbl-1 expression pattern suggests a role for neuronal cells in global size regulation as well as male tail patterning.

Research note Reproductive interference in concurrent infections of two Protopolystoma species (Monogenea: Polystomatidae)

The prevention of interspecific reproductive interference is one possible explanation for spatial niche divergence between congeneric monogeneans. However, there is little direct evidence that reproductive interactions with other species are potentially deleterious to the majority of parasitic platyhelminths. Xenopus fraseri-like clawed toads from lowland rainforest in eastern Democratic Republic of Congo are infected by two species of polystomatid monogenean, Protopolystoma fissilis and Protopolystoma ramulosus. Both occur as adults in the host urinary bladder, and exhibit identical copulatory structures and similar body sizes. The small area of the habitat in relation to parasite body size makes close proximity inevitable in concurrent infections. Eggs were collected from five naturally infected hosts: two of these harboured concurrent infections, and three were infected with P. fissilis only. Eggs from concurrent infections showed reduced viability (57.6% embryonation, n = 413) compared with those from P. fissilis-only infections (85.2%, n = 439). This effect may be due to some form of reproductive interference, possibly failure to develop following interspecific cross-fertilisation.

Surface morphology of the fish parasite <i>Chonopeltis victori</i> Avenant- Oldewage, 1991 and aspects of the histomorphology

The ultrastructure and aspects of the histomorphology of Chonopeltis victori, parasitic on Labeo rosae, L. congoro, L. ruddi, L. cylindricus and Barbus marequensis, are described from scanning electron micrographs and transverse sections. Chonopeltis victori is characterised by sharply pointed tips of the abdomen which are directed outward. Sexual dimorphism is particularly evident from the structure of the natatory lobes on the fourth swimming legs and the accessory copulatory structures on the second, third and fourth swimming legs of males. The most striking feature on leg four of the male is the peg. The elevated peg appears tubular, but the sides are not fused. On the inner collar elliptical projections, each with a central, circular pore, are present. On the elongated outer collar small indentions occur peripherally. The dorsal surface of the peg is subterminally covered by elongated scales. The ventral surface of the thorax and swimming legs are covered with different shapes of posteriorly directed scales. Interspersed amongst these scales, as well as on the dorsal surface, eight types of setae are present in large numbers. The possible function of the peg and other structures are described.

Sensory regulation of male mating behavior in Caenorhabditis elegans.

C. elegans male mating behavior comprises a series of steps: response to contact with the hermaphrodite, backing along her body, turning around her head or tail, location of the vulva, insertion of the two copulatory spicules into the vulva, and sperm transfer. By ablation of male-specific copulatory structures and their associated neurons, we have identified sensory structures and neurons that participate in each of these steps: the sensory rays mediate response to contact and turning; the hook, the postcloacal sensilla, and the spicules mediate vulva location; the spicules also mediate spicule insertion and regulate sperm transfer. Generally, successful completion of each step places the male in a position to receive a cue for the next step in the pathway. However, the high degree of sensory regulation allows the male to execute some steps independently.

The genus Argulus (Crustacea: Branchiura) in Africa: identification keys

Two keys to the African species of Argulus have been constructed, the first of which is applicable to either sex and the second is based on the male accessory copulatory structures.

Suckers and Other Bursal Structures of Pomphorhynchus bulbocolli and Acanthocephalus dirus (Acanthocephala)

Accessory copulatory structures in the bursa of Pomphorhynchus bulbocolli include 2 suckers on the inner surface and bursal rays. A stylet was present in the penis of this species. Two suckers were present in the bursa of Acanthocephalus dirus, but bursal rays and a stylet in the penis were not observed. This is the first report of suckers present in the bursas of acanthocephalans. Copulatory cement caps and holes surrounded by a ring approximating the inner bursal diameter and not covered by a cap were present on the sides of some P. bulbocolli, indicating the possibility of hypodermic insemination in this species.

Argulus papuensis n. sp., a new fish louse (Crustacea: Branchiura) from Papua New Guinea

A new species of Argulus (Crustacea: Branchiura) is described from a sleeper, Bunaka herwerdeni (Weber), in Papua New Guinea. It is characterised by the shape of the respiratory areas, the number and shape of supporting sclerites in the suckers of the first maxilla, as well as the accessory copulatory structures on the third and fourth legs of the male.

Parelaphostrongylus andersoni (Nematoda: Protostrongylidae) in caribou (Rangifer tarandus) of northern and central Canada

Woodland (Rangifer tarandus caribou) and barren ground (R. t. groenlandicum) caribou are reported for the first time as hosts of Parelaphostrongylus andersoni, greatly extending the known geographic range of this muscle nematode. Up to 56% of caribou in the Beverly herd, central Northwest Territories, passed dorsal-spined first-stage larvae in their feces. Animals less than 3 years old were more frequently infected and passed greater numbers of larvae than older animals. Larval output in winter and spring did not differ. Adults of the four elaphostrongyline nematodes known to occur in caribou are distinguished by their location in the host, the size of the worms, and the size and morphology of the male copulatory structures. There is an urgent need for tested and improved methods of differentiating larvae of P. andersoni and other elaphostrongyline nematodes from those of P. tenuis that cause neurologic disease in various North American cervids. Demonstration of the occurrence of P. andersoni in Rangifer sp. in North America raises the possibility that it originated in Eurasian cervids and may still occur in the Old World.

A means of determining sex in larval Tarsonemidae (Acari: Heterostigmata) based on external structure

Larval males generally differ from larval females of Tarsonemidae in having three, rather than two, pairs of small pseudanal setae flanking the uropore. This sex-linked difference in larvae correlates with a similar difference in adults: females retain only one pair of them, as setae, whereas males retain two pairs, modified into accessory copulatory structures. The possible usefulness of determining sex in larval tarsonemids is discussed. In some taxa, however, these setae are vestigial or so minute as to not be useful in sex determination.

Surface topography of the branchiuranArgulus appendiculosus Wilson, 1907 as revealed by scanning electron microscopy

The body surface of adultArgulus appendiculosus is characterized by a carapace which dorsally is devoid of surface ornamentation except for the presence of a series of grooves and sutures which are similarly arranged in all specimens. The ventral surface of the carapace is bounded laterally by spines and medially by unadorned respiratory areas. Sucking discs possess circumferential flanges with marginal papilae and supporting rods composed of two elements. Sexual dimorphism is particularly evident in the structure of the natatory lobes of the fourth swimming legs and in the presence of accessory copulatory structures on second, third and fourth swimming legs of males. A previously undescribed pocket on the coxa of the third swimming appendage of males may function together with the peg and socket apparatus in the clasping of males and females during copulation. Ventral surfaces of the thorax and maxillae are covered with posteriorly directed scales which have distal ends bearing comb-like teeth. Presumed sensory structures on the body surface are of at least two types: (1) recurved spinous projections which often arise from cuticular blebs, and (2) small circular pits containing papillae which do not project beyond the rim of the pit. ManyA. appendiculosus had attached peritrichous ciliates on the lateral and ventral body surfaces.

The taxonomic status of the Bermuda beach cricket (Orthopteroida: Gryllidae)

Abstract. Gryllus bermudensis Caudell from the Bermudas is compared with its closest relative G.firmus Scudder from the southeastern seaboard of the U.S.A. The two are very similar: a few minor morphological differences, mainly in the male copulatory structures, have been detected; bermudensis differs from most, but not all, mainland populations of firmus in that it lacks a diapause; the calling songs and stridulatory apparatus are virtually indistinguishable. They interbreed freely, and apparently indefinitely in captivity, but there is an initial fall‐off in fertility when ♀bermudensis are mated with ♂firmus from North Carolina, although not in the reciprocal cross. The reduction is not sustained at so low a level in the hybrids. G.bermudensis is therefore regarded as a subspecies of G.firmus. The most closely related species is probably G.ovisopis T. J. Walker.

A Redescription and Neotype Designation for Parelaphostrongylus odocoilei (Nematoda: Metastrongyloidea)

Parelaphostrongylus odocoilei is redescribed from worms collected from the type host (Odocoileus hemionus columbianus) in California, as well as material from experimentally infected mule deer (O. h. heminus) in Alberta. A single male specimen from the California material is designated as the neotype of P. odocoilei, the type species of Parelaphostrongylus. The male copulatory structures of the 3 species of Parelaphostrongylus (P. tenuis, P. anderscni, and P. odocoilei) are reviewed and a key for the identification of males is provided.

On the occurrence of the subtribe mekongianina (Orthoptera : Acridoidea : Pyrgomorphidae) in India

Abstract Mekongiella wardi is reported for the first time from India. Concealed copulatory structures of M. wardi are figured.

The ultrastructure of the cuticle of the nematode Syphacia obvelata (Rudolphi, 1802). III. Cuticle associated with the male reproductive structures

Mamelons of male Syphacia obvelata are ventrally situated copulatory structures bounded by cuticle, and internally composed of muscles. Extracuticular spines are found at the apex of each annulus making up the mamelon. The cloaca is formed by an invagination of body wall cuticle, as is the spicule sheath (a portion of the cloacal wall surrounding the free end of the spicule). The spicule, accessory piece, and papillae are innervated and probably function as mechanoreceptors facilitating the positioning of the cloacal region over the vulva during copulation. Dense material forming the gubernaculum, spicule, and accessory piece is distinct from the body wall cuticle. The cortex and basal zones are apposed around the cloacal opening and probably strengthen this area. On the other hand, cuticle lining the cloaca is composed of cortex and an expanded inner zone of matrix material. This matrix material would allow considerable modification in the shape of the cloacal wall during copulation. The apposition of cortex and basal zones over the tip of anal papillae would ensure effective transmission of pressures to the nerve process.

Stereoscan electron microscope observations on Jaera nordmanni nordica Lemercier (Crustacea: Isopoda)

The mouthparts, male secondary sex characters and male copulatory structures of Jaera nordmanni nordica Lemercier (Crustacea: Isopoda) have been viewed with the Stereoscan Electron Microscope, and compared with the corresponding structures for the closely related Jaera albifrons Leach group of species. The mouthparts are identical thus suggesting a similar diet and feeding mechanism, and that competition for food occurs between J. n. nordica and Jaera ischiosetosa Forsman, the most euryhaline member of the/, albifrons group, in localities where they overlap. The role of the secondary sex characters in maintaining genetic isolation in the three forms of J. nordmanni is discussed with reference to the information available on the J. albifrons group. The male praeoperculum and appendix masculinum of J. n. nordica are described and a possible route for the transfer of spermatophores from the male to the female is postulated.