Spermatozoal ultrastructure of spiny oysters (Spondylidae, Bivalvia) including a comparison with other bivalves

Sperm ultrastructure in three representative species of the marine bivalve family Spondylidae (spiny or thorny oysters) is examined and compared with available data on other bivalves, especially other families of the subclass Pteriomorphia. Spondylid spermatozoa are of the externally fertilizing aquasperm. type (ect-aquasperm). The acrosomal vesicle is conical with a deep basal invagination extending almost the full length of the vesicle. Vesicle contents are divisible into an inner, highly electron-dense anterior layer and a less dense posterior layer. The anterior layer is folded back on itself posteriorly and exhibits radiating plates (best developed peripherally). The vesicle rests on, and is partially embedded in, an extensive granular deposit of subacrosomal. material at the nuclear apex. This deposit extends partly into acrosomal vesicle invagination and also fills a broad depression in the anterior of the nucleus. No pre-formed axial rod (perforatorium) is present. The nucleus is round-pyriform and its contents coarsely fibrogranular. At the base of the nucleus, four broad depressions partially accommodate the midpiece mitochondria. The midpiece consists the four spherical mitochondria and the proximal and distal centrioles. The centrioles are arranged at approximately 90degrees to each other, and each consists of nine, angularly-oriented, microtubular triplets embedded in a granular matrix. A short, periodically banded rootlet connects the proximal centriole to the nuclear fossa, whereas the distal centriole, which forms the basal body to the flagellar axoneme, is anchored to the plasma membrane by nine terminally forked satellite fibres. Extensive deposits of putative glycogen rosettes surround the centrioles and mitochondria. The flagellum consists of a 9+2 axoneme sheathed by the plasma membrane. Spondylid spermatozoa strongly resemble those of the Pectinidae, further confirming the traditional view (based on comparative anatomy and shell morphology) of a close relationship between the Spondylidae and the Pectinidae. Differences in acrosomal shape and dimensions were noted between the three species examined, indicating potential taxonomic utility for comparative sperm ultrastructure within the Spondylidae.

The walkeriana species-group of Euhesma Michener (Hymenoptera: Colletidae: Euryglossinae)

The walkeriana species-group of iridescent Euhesma bees is described with the following nine species considered new: E. allunga, E. banksia, E. bronzus, E. dongara, E. lobata, E. spinola, E. sybilae, E. viridescens and E. xana. Two new synonymies are proposed: E. mica (Cockerell) with E. neglectula (Cockerell), and E. halictoides (Rayment) with E. latissima (Cockerell). A key enables the separation of species, and distributions are mapped.

Phylogenetic revision of Agapophytus Guerin (Diptera : Therevidae : Agapophytinae)

Morphologically diverse and species-rich, the endemic Australasian genus Agapophytus is revised. Eleven previously described species are redescribed and twenty-nine species are described for the first time: A. adonis, sp. nov., A. annamariae, sp. nov., A. antheliogynaion, sp. nov., A. asprolepidotos, sp. nov., A. atrilaticlavius, sp. nov., A. biluteus, sp. nov., A. borealis, sp. nov., A. caliginosus, sp. nov., A. cerrusus, sp. nov., A. chaetohypopion, sp. nov., A. chrysosisyrus, sp. nov., A. decorus, sp. nov., A. dieides, sp. nov., A. discolor, sp. nov., A. eli, sp. nov., A. fenestratum, sp. nov., A. galbicaudus, sp. nov., A. labifenestellus, sp. nov., A. laparoceles, sp. nov., A. lissohoplon, sp. nov., A. lyneborgi, sp. nov., A. notozophos, sp. nov., A. novaeguineae, sp. nov., A. pallidicrus, sp. nov., A. palmulus, sp. nov., A. paramonovi, sp. nov., A. septentrionalis, sp. nov., A. yeatesi, sp. nov. and A. zebra, sp. nov. All 40 species of Agapophytus were compared in a cladistic analysis with three species of Acupalpa Krober using 134 states across 58 adult morphological characters. The analysis resulted in 36 most parsimonious trees with a length of 240 steps. The phylogenetic relationships of the species of Agapophytus are discussed with three main clades recognised: A. dioctriaeformis clade, A. australasiae clade and A. queenslandi clade.

Revision of Australian Clistoabdominalis (Diptera : Pipunculidae)

The 29 Australian species of Clistoabdominalis Skevington are revised and a phylogenetic analysis is presented. The following 23 new species are proposed: Clistoabdominalis ancylus, C. angelikae, C. capillifascis, C. carnatistylus, C. collessi, C. colophus, C. condylostylus, C. danielsi, C. dasymelus, C. digitatus, C. exallus, C. gaban, C. gremialis, C. lambkinae, C. lingulatus, C. mathiesoni, C. nutatus, C. octiparvus, C. scalenus, C. scintillatus, C. tasmanicus, C. tharra, and C. yeatesi. Pipunculus picrodes Perkins is proposed as a junior synonym of C. trochanteratus (Becker). Diagnoses and an illustrated key to species are provided. A summary of host records for all Australian species of Pipunculidae is presented to clarify confusion in the literature. Pipunculidae are documented hilltopping for the first time. This mating strategy is used by many species of Clistoabdominalis and patterns of hilltopping within the genus are examined.

Phylogenetic classification of Eudorylini (Diptera: Pipunculidae)

The phylogenetic relationships of members of Eudorylini (Diptera: Pipunculidae: Pipunculinae) were explored. Two hundred and fifty-seven species of Eudorylini from all biogeographical regions and all known genera were examined. Sixty species were included in an exemplar-based phylogeny for the tribe. Two new genera are described, Clistoabdominalis and Dasydorylas. The identity of Eudorylas Aczél, the type genus for Eudorylini, has been obscure since its inception. The genus is re-diagnosed and a proposal to stabilize the genus and tribal names is discussed. An illustrated key to the genera of Pipunculidae is presented and all Eudorylini genera are diagnosed. Numerous new generic synonyms are proposed. Moriparia nigripennis Kozánek & Kwon is preoccupied by Congomyia nigripennis Hardy when both are transferred to Claraeola, so Cla. koreana Skevington is proposed as a new name for Mo. nigripennis.

Phylogenetic revision of the flightless Australian genus Apterotheca Gebien (Coleoptera : Tenebrionidae : Coelometopinae)

Members of the flightless genus Apterotheca Gebien (Coleoptera : Tenebrionidae) are mostly restricted to the high elevation rainforests of the Wet Tropics World Heritage Area of north-eastern Australia. This region has been recognised as an 'epicentre of evolution for low vagility animals'. The genus Apterotheca is the most diverse low vagility insect taxon known in this region. Forty-four species are included here in a revision of the genus. Three of these species were previously included in Apterotheca (A. antaroides (Pascoe), A. besti (Blackburn) and A. punctipennis Carter), four were previously included in other genera (A. australis (Kulzer), comb. nov. and A. punctifrons (Gebien), comb. nov. in Apterophenus Gebien, A. costata (Buck), comb. nov. in Caxtonana Buck and A. pustulosa (Carter), comb. nov. in Austropeus Carter) and 37 are new. The monotypic genera Austropeus Carter, syn. nov. and Caxtonana Buck, syn. nov. are proposed as new synonyms of Apterotheca. A lectotype for A. punctipennis and A. besti are designated. A key to the species of Apterotheca and a phylogenetic analysis based on the morphological features of adults, as well as a discussion of character evolution, are also included. Data presented here represent the framework for future studies on the determinants of the patterns of diversity found in the Wet Tropics.

Developmental expression of a class IV POU gene in the gastropod Haliotis asinina supports a conserved role in sensory cell development in bilaterians

POU-IV genes regulate neuronal development in a number of deuterostomes (chordates) and ecdysozoans (arthropods and nematodes). Currently their function and expression in the third bilaterian clade, the Lophotrochozoa, comprising molluscs, annelids and. their affiliates, is unclear. Herein we characterise the developmental expression of HasPOU-IV in the gastropod mollusc, Haliotis asinina. The POU-IV gene is transiently expressed in I I distinct larval territories during the first 3 days of development. HasPOU-IV is first expressed in sets of ventral epidermal cells in the newly hatched trochophore larvae. As larval morphogenesis proceeds, we observe HasPOU-IV transcripts in cells that putatively form a range of sensory systems including chemo- and mechanosensory cells in the foot, cephalic tentacles, the ctenidia. the geosensory statocyst and the eyes. By comparing HasPOU-IV expression with POU-IV genes in other bilaterians we infer that this class of POU-domain genes had an ancestral role in regulating sensory cell development.

Feeding ecology of a carnivorous bladderwort (Utricularia uliginosa, Lentibulariaceae)

The terrestrial carnivorous bladderwort, Utricularia uliginosa Vahl. (Lentibulariaceae) was studied to determine the species assemblage present in traps of these plants in situ across four sites over 15 months. The immediate soil environment was also sampled to determine the fauna present, and to compare the fauna present in traps with the fauna in the environment. The soil fauna consisted of 10 taxon types, which occupied either pelagic, epibenthic or interstitial microhabitats. All were found in traps of U. uliginosa, with the main prey being interstitial taxa followed by epibenthic and occasionally pelagic taxa. Numbers of individuals of the two most abundant soil taxa (nematodes, Elaphoidella) varied independently across the four sites over the 15 months of the study, as did numbers of Elaphoidella in the traps of U. uliginosa. Numbers of nematodes in the traps of U. uliginosa showed significant differences among sites, but not differences among times. Comparison of the trap fauna with the soil fauna revealed differences in relative abundance between soil samples and trap samples for two of the three taxa examined. There was an under-representation of nematodes in the traps relative to numbers in surrounding soil. There was an over-representation of the copepod Elaphoidella in the traps of U. uliginosa relative to numbers in soil at some of the times of sampling. Acarina were equally abundant in soil and trap samples. The patterns observed for Elaphoidella and nematodes may be due to selectivity in trapping by U. uliginosa, and/or differences in digestibility of the prey. Elaphoidella individuals were found to be attracted to U. uliginosa in a behavioural experiment. This may contribute to the over-representation of Elaphoidella in the traps of U. uliginosa in the field.