我国西南地区早寒武世小壳化石Sinosachites

采自四川峨嵋和云南会泽的磷酸盐化的Sinosachites骨片显示出中央沟和侧沟结构,并区别出三种不同类型的骨片(palmate,cultrate and siculate)。这一发现证实,产于澳大利亚的Thambetolepis(Jell,1981)是Sinosachites的晚出同义名。基于上述结构,该产地一些原定为Sachites和Halkieria的标本亦应归入Sinosachites。在Sinosachites属中确认出两个种,即产于华南的Sinosachites flabelliformis He和产于澳大利亚的Sinosachites delicatus(Jell)。在前一种中,左右型对称骨片的存在证实该动物两侧对称。骨片的基部通常保存为磷质内核,表明它比骨片壁更容易磷酸盐化,在组织学上它与骨片壁不同。骨片的基部可能原为有机质或部分矿化。在Sinosachites中,无帽状和束状骨片可能表明在coeloscleritophorans中halkieriids是一个介于wiwaxids和siphogonuchitids之间的类群。     

Ontogeny,morphology and taxonomy of the soft‐bodied Cambrian ‘mollusc’ Wiwaxia

The soft‐bodied Cambrian organism Wiwaxia poses a taxonomic conundrum. Its imbricated dorsal scleritome suggests a relationship with the polychaete annelid worms, whereas its mouthparts and naked ventral surface invite comparison with the molluscan radula and foot. 476 new and existing specimens from the 505‐Myr‐old Burgess Shale cast fresh light on Wiwaxia's sclerites and scleritome. My observations illuminate the diversity within the genus and demonstrate that Wiwaxia did not undergo discrete moult stages; rather, its scleritome developed gradually, with piecewise addition and replacement of individually secreted sclerites. I recognize a digestive tract and creeping foot in Wiwaxia, solidifying its relationship with the contemporary Odontogriphus. Similarities between the scleritomes of Wiwaxia, halkieriids, Polyplacophora and Aplacophora hint that the taxa are related. A molluscan affinity is robustly established, and Wiwaxia provides a good fossil proxy for the ancestral aculiferan – and perhaps molluscan – body plan.     

Lessons from parasitic flatworms about evolution and historical biogeography of their vertebrate hosts

Cophylogenetic studies investigate the evolutionary trends within host-parasite associations. Examination of the different levels of fidelity between host and parasite phylogenies provides a powerful tool to inspect patterns and processes of parasite diversification over host evolution and geological times. Within the phylum Platyhelminthes, the monogeneans are mainly fish parasites. The Polystomatidae, however, are known from the sarcopterygian Australian lungfish and tetrapods such as amphibians, freshwater turtles, and the African hippopotamus. Cophylogenetic and biogeographic vicariance analyses, supplemented by molecular calibrations, showed that the Polystomatidae may track the evolutionary history of the first aquatic tetrapods in the Palaeozoic age. Evolutionary lines of the major polystome lineages would also be intimately related to the evolution of their hosts over hundreds of millions years. Since the Mesozoic, evolution of polystomes would have been shaped mainly by plate tectonics during the break-up of Gondwanaland and subsequent dispersal of ancestral neobatrachian host lineages. Therefore the Polystomatidae could serve as a novel model to improve cophylogenetic tools and to inspect a suite of questions about the evolution of vertebrate hosts. To cite this article: O. Verneau et al., C. R. Biologies 332 (2009).     

A new genus and species of pennatulacean octocoral from equatorial West Africa (Cnidaria,Anthozoa, Virgulariidae)

A new genus and species of sea pen or virgulariid pennatulacean from the Gulf of Guinea in the tropical eastern Atlantic is described, and a key to the genera of the Virgulariidae is included. The new genus and species described here adds to the previously described five other genera of the family. It is distinguished by unique sclerite and polyp leaf characters from the superficially-similar genus Virgularia, which lacks conspicuous sclerites in the polyp leaves and coenenchyme (other than minute oval bodies that are generally <0.01 mm in length).     

Review of haploporid (Trematoda) genera with ornate muscularisation in the region of the oral sucker, including four new species and a new genus

Species of the Haploporidae Nicoll, 1914 with elaborate muscularisation of the oral sucker belong in three trematode genera, including three new species and a new genus from the intestine of fishes in Australian waters. Spiritestis Nagaty, 1948 is resurrected and S. herveyensis n. sp. is described from the mullet Moolgarda seheli (Forsskål) collected in Hervey Bay, Queensland, Australia; the latter differs from S. arabii Nagaty, 1948 in that the position of the genital pore is pharyngeal rather than post-pharyngeal and the geographical range is off Australia rather than the Red Sea. A new genus is proposed for two new species, with a uniquely ornamented oral sucker, which infect Australian scatophagids. Members of Capitimitta n. g. are distinguished from Waretrema Srivastava, 1937, species of which have a simple oral sucker with six radially arranged anterior muscular lobes, in that their oral sucker is V-shaped with six embedded muscular finger-like structures in the anteroventral portion. The relatively small C. darwinensis n. sp., collected from Selenotoca multifasciata (Richardson) at Darwin, Northern Territory, Australia, is distinguished from C. costata n. sp., collected from Scatophagus argus (Linnaeus) in the same locality and S. multifasciata off Brisbane, Australia, and by having smaller eggs, a vitellarium commencing at a level close to the ventral sucker rather than at greater than one ovarian length posterior to the ventral sucker, and shorter tegumental body spines. Sequence data of a c.2,500 bp region of the 3′ end of 18S, the entire ITS region and the 5′ end of the 28S revealed that Spiritestis and Capitimitta are not as closely related as some morphological features would suggest and are probably not the closest relative of each other. What has been reported as Waretrema piscicolum Srivastava, 1937 probably consists of several species, some in different genera, and one, based on material collected by Dr Masaaki Machida, is proposed as Spiritestis machidai n. sp. from Crenimugil crenilabis (Forsskål) off Japan. Phylogenetic hypotheses, based on analysis of an alignment of partial 28S sequences with other haploporids, provide a framework for the evaluation of interrelationships within the Haploporidae. These analyses show that: (1) Spiritestis and Capitimitta are supported within the Haploporidae; (2) branches to Forticulcita Overstreet, 1982, Saccocoelioides Szidat, 1954, Spiritestis and Capitimitta create a clade that is sister to haploporines from the Mediterranean Sea; (3) the branch to Saccocoelioides, Spiritestis and Capitimitta create a polytomy; and (4) the two new species of Capitimitta, plus an immature specimen of an unnamed species, form a monophyletic clade.     

Tommotiids from the early Cambrian (Series 2, Stage 3) of Morocco and the evolution of the tannuolinid scleritome and setigerous shell structures in stem group brachiopods

An assemblage of tannuolinid sclerites is described from the Amouslek Formation (Souss Basin) of the Anti‐Atlas Mountains in Morocco. The assemblage contains two species, Tannuolina maroccana n. sp., which is represented by a small number of mitral and sellate sclerites, and Micrina sp., represented by a single mitral sclerite. Tannuolina maroccana differs from other species of the genus in the presence of both bilaterally symmetrical and strongly asymmetrical sellate sclerites. This observation suggests that the scleritome of Tannuolina was more complex than previously thought and that this tommotiid may have held a more basal position in the brachiopod stem group than previously assumed. The shell structure of both T. maroccana and Micrina sp. is well preserved and exhibits two fundamentally different sets of tubular structures, only one of which was likely to contain shell‐penetrating setae. Based on these observations, the structure of the tannuolinid shell is discussed and its implications for the evolution of tubular microstructures in stem and crown group brachiopods are analysed.     

Cockroaches of genus Muzoa: morphology of the male genital sclerites and description of one new species (Dictyoptera,Blattodea, Ectobiidae,Nyctiborinae)

The male genital sclerites of cockroaches of genus Muzoa Hebard 1921 are described for first time and the new species Muzoa curtalata sp. n. is described and ilustrated. A dichotomous key to identify the species of genus Muzoa is given.     

Two new species of mazocraeid monogeneans from Clupanodon punctatus (Temminck & Schlegel) (Clupeiformes: Clupeidae) found in Daya Bay, South China Sea, with the proposal of Chelimazocraes n. g.

Chelimazocraes liaoi n. g., n. sp. and Chelimazocraes ascidiformis n. sp. (Monogenea: Mazocraeidae) are described from the gills of Clupanodon punctatus (Temminck & Schlegel) in Daya Bay (South China Sea). The new genus is characterised by the following features: (i) the haptor is distinctly separated from the body proper, and the arrangement of the clamps is bilaterally symmetrical but longitudinally heteromorphic; (ii) the anterior three pairs of clamps are of the mazocraeid-type, whereas the fourth pair is of a non-mazocraeid type with three sclerites; (iii) all three pairs of clamps are similar in shape but their size gradually becomes smaller from the anterior to the posterior; (iv) the inner spines of the copulatory organ have a similar shape; and (v) the testes are numerous and arranged longitudinally posterior to the ovary. The two new species are easily distinguished from other members of the Mazocraeidae by the unique structure of the fourth pair of clamps; however, there are some noticeable differences between the two species. The major differences are as follows: (i) the body of C. liaoi n. sp. is significantly larger than that of C. ascidiformis n. sp.; (ii) the anterior three pairs of clamps consist of different sclerites in the two species; and (iii) the copulatory organ has one pair of outer spines and 15–16 pieces of inner spines in C. liaoi n. sp. (vs two pairs of outer spines and 22–26 pieces of inner spines in C. ascidiformis n. sp.).     

Molecular phylogenetic evidence supports a new family of octocorals and a new genus of Alcyoniidae (Octocorallia,Alcyonacea)

Molecular phylogenetic evidence indicates that the octocoral family Alcyoniidae is highly polyphyletic, with genera distributed across Octocorallia in more than 10 separate clades. Most alcyoniid taxa belong to the large and poorly resolved Holaxonia–Alcyoniina clade of octocorals, but members of at least four genera of Alcyoniidae fall outside of that group. As a first step towards revision of the family, we describe a new genus, Parasphaerasclera gen. n., and family, Parasphaerascleridae fam. n., of Alcyonacea to accommodate species of Eleutherobia Pütter, 1900 and Alcyonium Linnaeus, 1758 that have digitiform to digitate or lobate growth forms, completely lack sclerites in the polyps, and have radiates or spheroidal sclerites in the colony surface and interior. Parasphaerascleridae fam. n. constitutes a well-supported clade that is phylogenetically distinct from all other octocoral taxa. We also describe a new genus of Alcyoniidae, Sphaerasclera gen. n., for a species of Eleutherobia with a unique capitate growth form. Sphaerasclera gen. n. is a member of the Anthomastus–Corallium clade of octocorals, but is morphologically and genetically distinct from Anthomastus Verrill, 1878 and Paraminabea Williams & Alderslade, 1999, two similar but dimorphic genera of Alcyoniidae that are its sister taxa. In addition, we have re-assigned two species of Eleutherobia that have clavate to capitate growth forms, polyp sclerites arranged to form a collaret and points, and spindles in the colony interior to Alcyonium, a move that is supported by both morphological and molecular phylogenetic evidence.     

A new species of Ovabunda (Octocorallia,Xeniidae) from the Andaman Sea,Thailand with notes on the biogeography of this genus

A survey of xeniid octocorals was carried out in the waters off Southwestern Thailand in September, 2007. Microscopic investigation of the colonies revealed that three specimens belonged to the genus Ovabunda. Gross morphological examination is presented here accompanied by scanning electron micrographs of the sclerites. Molecular phylogenetic analysis showed identical genotypes at mtMutS, COI, and 28S rDNA for all three specimens and supports their generic assignment. Colony size and shape, sclerite size, and pinnule arrangement differ from nominal species of Ovabunda and thus a new species, O. andamanensis is introduced here. This work also presents a new eastern geographical record for the genus Ovabunda.     

Australian lungfish, <Emphasis Type="Italic">Neoceratodus forsteri</Emphasis>, threatened by a new dam

The Australian lungfish, Neoceratodus forsteri, exists as remnant natural populations in two rivers of south-east Queensland, Australia, and several translocated populations. Lungfish habitats have been impacted by agriculture and forestry, alien plants and fish and by river impoundment and regulation of flows. The species has been listed as vulnerable under Australian Commonwealth legislation. A proposal to construct Traveston Crossing Dam on the free-flowing main channel of the upper Mary River could seriously threaten the lungfish. The dam can be stopped by Commonwealth legislation if important populations of lungfish in the Mary River are likely to be significantly impacted by the new dam. This paper assembles evidence that impoundment of the Mary River and regulation of river flows are likely to decrease and fragment important lungfish populations, disrupt the breeding cycle, reduce juvenile recruitment, and isolate and decrease habitat availability/quality to such an extent that the species is likely to decline. Proposed mitigation strategies include fish transfer facilities, provision of flow releases from the dam (environmental flows) to sustain lungfish habitat and breeding downstream, and translocation of hatchery-reared juvenile lungfish into suitable natural habitats. These mitigation efforts may not be sufficient to secure the genetic diversity and long-term viability of lungfish populations in the Mary River.     

Brain – Endocast Relationship in the Australian Lungfish,Neoceratodus forsteri,Elucidated from Tomographic Data (Sarcopterygii: Dipnoi)

Although the brains of the three extant lungfish genera have been previously described, the spatial relationship between the brain and the neurocranium has never before been fully described nor quantified. Through the application of virtual microtomography (μCT) and 3D rendering software, we describe aspects of the gross anatomy of the brain and labyrinth region in the Australian lungfish, Neoceratodus forsteri and compare this to previous accounts. Unexpected characters in this specimen include short olfactory peduncles connecting the olfactory bulbs to the telencephalon, and an oblong telencephalon. Furthermore, we illustrate the endocast (the mould of the internal space of the neurocranial cavity) of Neoceratodus, also describing and quantifying the brain-endocast relationship in a lungfish for the first time. Overall, the brain of the Australian lungfish closely matches the size and shape of the endocast cavity housing it, filling more than four fifths of the total volume. The forebrain and labyrinth regions of the brain correspond very well to the endocast morphology, while the midbrain and hindbrain do not fit so closely. Our results cast light on the gross neural and endocast anatomy in lungfishes, and are likely to have particular significance for palaeoneurologists studying fossil taxa.     

Sinodima jenisi gen. et sp. nov., a new wingless click-beetle from the mountains of Hunan,China (Elateridae: Dendrometrinae: Dimini)

Sinodima gen. nov., a new genus in the click-beetle tribe Dimini Candèze, 1863 from the mountains in Hunan, China, is described and figured here to accommodate S. jenisi sp. nov. The new genus is easily recognizable from all other Dimini by the following combination of characters: short antennomeres II and III; transverse pronotum with inconspicuous anterior angles; arcuate prosternal process; mesoventrite with straight frontal margin and oblique and straight sides; absent hind wings; and absent sclerites or spines in the bursa copulatrix. Additionally, we compare Sinodima gen. nov. with the morphologically similar genera, and discuss the systematic position of this genus within Dimini.www.zoobank.org/urn:lsid:zoobank.org:pub:91F22A25-E1F1-4EC4-B3EF-5D632B83FDE5     

Monitoring age‐related trends in genomic diversity of Australian lungfish

An important challenge for conservation science is to detect declines in intraspecific diversity so that management action can be guided towards populations or species at risk. The lifespan of Australian lungfish (Neoceratodus forsteri) exceeds 80 years, and human impacts on breeding habitat over the last half century may have impeded recruitment, leaving populations dominated by old postreproductive individuals, potentially resulting in a small and declining breeding population. Here, we conduct a “single‐sample” evaluation of genetic erosion within contemporary populations of the Australian lungfish. Genetic erosion is a temporal decline in intraspecific diversity due to factors such as reduced population size and inbreeding. We examined whether young individuals showed signs of reduced genetic diversity and/or inbreeding using a novel bomb radiocarbon dating method to age lungfish nonlethally, based on ¹⁴C ratios of scales. A total of 15,201 single nucleotide polymorphic (SNP) loci were genotyped in 92 individuals ranging in age from 2 to 77 years old. Standardized individual heterozygosity and individual inbreeding coefficients varied widely within and between riverine populations, but neither was associated with age, so perceived problems with recruitment have not translated into genetic erosion that could be considered a proximate threat to lungfish populations. Conservation concern has surrounded Australian lungfish for over a century. However, our results suggest that long‐lived threatened species can maintain stable levels of intraspecific variability when sufficient reproductive opportunities exist over the course of a long lifespan.     

Cranial nerves in the Australian lungfish,Neoceratodus forsteri,and in fossil relatives (Osteichthyes: Dipnoi)

Three systems, two sensory and one protective, are present in the skin of the living Australian lungfish, Neoceratodus forsteri, and in fossil lungfish, and the arrangement and innervation of the sense organs is peculiar to lungfish. Peripheral branches of nerves that innervate the sense organs are slender and unprotected, and form before any skeletal structures appear. When the olfactory capsule develops, it traps some of the anterior branches of cranial nerve V, which emerged from the chondrocranium from the lateral sphenotic foramen. Cranial nerve I innervates the olfactory organ enclosed within the olfactory capsule and cranial nerve II innervates the eye. Cranial nerve V innervates the sense organs of the snout and upper lip, and, in conjunction with nerve IX and X, the sense organs of the posterior and lateral head. Cranial nerve VII is primarily a motor nerve, and a single branch innervates sense organs in the mandible. There are no connections between nerves V and VII, although both emerge from the brain close to each other. The third associated system consists of lymphatic vessels covered by an extracellular matrix of collagen, mineralised as tubules in fossils. Innervation of the sensory organs is separate from the lymphatic system and from the tubule system of fossil lungfish.     

First monogenean flatworm from a microhylid frog host: Kankana, a new polystome genus from Madagascar

Kankana manampoka n. gen., n. sp. (Monogenea, Polystomatidae), is described from the urinary bladder of the narrow-mouthed frog Platypelis pollicaris. This is the first record of a polystome from the Microhylidae and the third polystome genus from Madagascar, next to Metapolystoma and Madapolystoma. The extensive uterus and presence of hamuli resemble Metapolystoma but the vitellarium confined to the lateral fields in Kankana is different. Madapolystoma also has an extensive uterus but contain only up to 32 advanced developed larvae. Based on the extensive uterus filling the body proper and the vitellarium confined to two lateral fields posterior in the body this new polystome resembles Eupolystoma known from Africa and India. However, unlike Eupolystoma, the gonads are in the middle of the body, vaginae are lacking and a pair of hamuli is present. A molecular phylogenetic analysis of concatenated 18S and 28S ribosomal RNA gene sequences supplemented by genetic distances inferred from 28S and COI sequences showed that this new genus is more related to Madapolystoma, a genus only reported from Madagascar, than to Eupolystoma known from Africa and India and Metapolystoma known from Africa and Madagascar.     

Two new species of gorgonian octocorals from the Tropical Eastern Pacific Biogeographic Region (Cnidaria,Anthozoa, Gorgoniidae)

The gorgoniid Eugorgia is exclusively an eastern Pacific genus. It has a wide geographic and bathymetric range of distribution, found from California to Perú and extends down to 65 m deep. Two new species are herein described. The morphological characters were analyzed and illustrated by light and scanning electron microscopy. Eugorgia beebei sp. n. can be distinguished by its white, ascending, sparse colony growth. Eugorgia mutabilis sp. n. can be distinguished by its white colony that changes color after collection, and the conspicuous sharp-crested disc sclerites. From a morphological point of view the new species are related to the daniana-group, the rubens-group and the siedenburgae-group of Eugorgia; their affiliations, and the proposal of a new group are discussed. These new species increases the number of species in the genus to 15, and contribute to the knowledge of the eastern Pacific octocoral biodiversity.     

A view of early vertebrate evolution inferred from the phylogeny of polystome parasites (Monogenea: Polystomatidae)

The Polystomatidae is the only family within the Monogenea to parasitize sarcopterygians such as the Australian lungfish Neoceratodus poisteri and freshwater tetrapods (lissamphibians and chelonians). We present a phylogeny based on partial 18S rDNA sequences of 26 species of Polystomatidae and three taxon from the infrasubclass Oligonchoinea (= Polyopisthocotylea) obtained from the gills of teleost fishes. The basal position of the polystome from lungfish within the Polystomatidae suggests that the family arose during the evolutionary transition between actinopterygians and sarcopterygians, ca. 425 million years (Myr) ago. The monophyly of the polystomatid lineages from chelonian and lissamphibian hosts, in addition to estimates of the divergence times, indicate that polystomatids from turtles radiated ca. 191 Myr ago, following a switch from an aquatic amniote presumed to be extinct to turtles, which diversified in the Upper Triassic. Within polystomatids from lissamphibians, we observe a polytomy of four lineages, namely caudatan, neobatrachian, pelobatid and pipid polystomatid lineages, which occurred ca. 246 Myr ago according to molecular divergence-time estimates. This suggests that the first polystomatids of amphibians originated during the evolution and diversification of lissamphibian orders and suborders ca. 250 Myr ago. Finally, we report a vicariance event between two major groups of neobatrachian polystomes, which is probably linked to the separation of South America from Africa ca. 100 Myr ago.