The evolutionary and biomechanical implications of snout and proboscis morphology in Caenogastropoda (Mollusca: Gastropoda)

The caenogastropod proboscis is a complex morphological adaptation to a carnivorous diet. This comparative morphological investigation of proboscis and snout anatomy in Caenogastropoda shows that there is undescribed diversity in both snout/proboscis wall composition and introversion/retraction musculature. There is morphological evidence which suggests that a proboscis evolved separately in at least four separate caenogastropod groups, each characterized by the presence of novel retractor muscles and different modifications of plesiomorphic “aortic muscles”. The biomechanical operation of the proboscis and snout utilizes a hydrostatic skeleton, but several higher caenogastropods have evolved a complex muscular hydrostat in the snout/proboscis wall which may mitigate the need to isolate the proboscis haemocoel during proboscis eversion.     

II.—Association between sessile colonial hydroids and fishes

Résumé

1. 1. There is a symbiosis between Sertularia operculata and Squalus acanthias, and between Seralia lendigera and Hippocampus ramulosus—there being but a single case reported for each pair of organisms. It is probable that these associations are entirely accidental.

2. 2. Of Stylactis minoi and Minous inermis, no fewer than twenty-nine specimens of the fish (presumably all ever taken) wherever found—and they have been taken from five widely distant stations on both coasts of India, and from Japan—were infested with the hydroid. Furthermore, so far as known, this particular hydroid has never been found save on this particular fish (inermis). These facts would seem to indicate that this is a purposive or obligate symbiosis.

3. 3. About one hundred specimens of Hypsagonus quadricornis were taken in Puget Sound. Thirty-seven of these were preserved, and ten of them were found to be sparsely covered with Perigonimus pugetensis. Other specimens of the fish taken outside Puget Sound and in Behring Sea all lacked the hydroid. Consideration of all these facts leads to the conclusion that the association is symbiotic and more or less accidental.

4. 4. One case has been presented of Hydrichthys mirus attached to Seriola zonata in Narragansett Bay. Parasitism is alleged, but the proofs offered, that there was some apparent degeneration on the part of the hydroid and some slight evidence of wasting away of the muscles of the fish at the point of attachment, are at best inconclusive, there being no evidence from sections presented to show actual anastomosis of the tissues of the two organisms. From the evidence presented one must conclude that this is only a case of symbiosis.

5. 5. One case is known of the attachment of a Nudiclava to a fish, Monacanthus, from the Andaman Sea. Parasitism is alleged in the title of the paper, but disclaimed in the text, since, in sections cut through the basal plate and the skin to which it was attached, such was not proven. Furthermore, the finding of food in the hydranths discounts the idea of parasitism. This case also must be classed as a symbiosis.

6. 6. True parasitism has been repeatedly shown to exist between an aberrant hydroid, Polypodium hydriforme, and the ovarian eggs of the Volga sterlet, Acipenser ruthenus. This has been definitely established by the work of four investigators, extending in time from 1872 to 1922—a half century. Except in its earliest stages, Polypodium has the nutritive cell-layer of its stolon, the endoderm, on the outside bathed in the egg-yolk. Later this becomes inverted and a large amount of yolk is carried into the common cavity. The egg is used up in nourishing the parasite.

7. 7. True parasitism has been shown between Hydrichthys boycei and numerous individuals of three species of fishes—Ambassis natalensis, Mugil sp., and an undetermined fish belonging to the Glyphidodontidæ—in Durban Bay, South Africa. The parasites were attached to various parts of the fishes, especially the fins. At the points of attachment, haustoria were sent down into flesh and into blood-vessels, and by means of these the parasite fed on the tissues of its host. Furthermore, on none of the hydranths were tentacles ever found, nor was any food ever found in them. Strange to say, the parasite never covers any large area of the fish, and apparently presently drops off leaving a scar behind.

     

Biting mechanism of the amphipod Anonyx (Crustacea: Amphipoda: Lysianassoidea)

Anonyx amphipods feed extensively on dead or weakened animals, often of large size. They cut off strips of food using the wide incisor processes of their mandibles like a pair of shears. The mandibles and associated mouthparts are specialized for this shearing action. The strips of food are coiled and packed into their proventriculi.     

Reproductive aspects of Leptodactytus hylaedactylus (Anura: Leptodactylidae), a member of the Leptodactylus marmoratus species group,with a description of tadpoles and calls

In this paper we describe some aspects of the reproductive biology of Leptodactylus hylaedactylus from open areas of Central Amazonia, Brazil. We describe the calling site, reproductive season, daily pattern of calling activity, chamber structure, vocalizations and tadpole morphology. Males of Leptodactylus hylaedactylus called amidst grasses and bushes in open and urban areas, throughout the year, and a greater number of males were heard in the period from 16:00 to 20:00 h. The eggs are deposited in underground chambers, which are spherical or elliptical. Larval development occurs inside the chambers. Two types of vocalizations were detected, the advertisement and the territorial call. The advertisement call of the species studied herein differs from other calls described for L. hylaedactylus from other localities of Brazil, but is very similar to that described from Peru. Tadpole morphology is similar to that described from individuals in French Guiana.     

Canopy fogging,a method of collecting living insects for investigations of life history strategies

Results of an intensive and diverse sampling programme of ground beetles (Carabidae), carried out in North Sulawesi (Indonesia), indicate that for some arboreal species of this group insecticide fogging is the most productive method of collecting. Specimens collected using this technique have provided important information on the life history strategies of arboreal carabids. The use of an insecticide with high knock-down and low kill components allowed some individuals collected to recover sufficiently to reproduce on subsequent provision of suitable climatic conditions. These results indicate that insecticides can be used to collect samples of species of arboreal arthropods not normally collected by other techniques for taxonomic, life history and other biological studies.     

Reflection of the Neogene–Quaternary phylogeography in the recent distribution limiting climatic factors of eight Mediterranean Phlebotomus species (Diptera: Psychodidae)

The diversification of Mediterranean Phlebotomus species occurred during the Neogene and Quaternary periods. The climatic and geographical history of the Mediterranean area plausibly influenced the climatic requirements of recent sand fly species. Our aim was to investigate the European zoogeography and the climate-based ecological groups of eight Phlebotomus species considering the phylogeography of the studied taxa. Jaccard index calculation, hierarchical cluster and principal component analyses were performed. The results of Jaccard-coefficient calculations may indirectly refer to the former existence of three possible glacial refuges of sand fly populations in Europe: an Iberian, an Apennine and a Balkan Peninsula–Asia Minor refuge. Three main climatic groups of the studied sand fly species were distinguished, namely the so-called ‘Trans-Mediterranean’, ‘East Mediterranean’ and ‘West Mediterranean’ groups. Our results suggest that the ancestor of Phlebotomus similis and Phlebotomus sergenti was adapted to the hot, dry summer Mediterranean climate during the late Neogene. The third member of this climate group, Phlebotomus papatasi because of co-adaptation shows similar climatic requirements as P. similis and P. sergenti. The five Larroussius species studied should have evolved under moister climatic conditions. Species of the ‘West Mediterranean’ group were adapted to the milder and wetter oceanic climate of Atlantic coasts. The species of the ‘East Mediterranean’ group diversified under the less balanced climate of the East Mediterranean. The recent climatic requirements and the European distribution of the studied species is the consequence of the complex Quaternary–Neogene geographical and climatic history of their former habitats in the Old continent. The adaptation of the ancestors of the studied sand fly species to the changing geographical and climatic factors of Europe are discussed.     

Exploitation of Cornucopina tuba (Bryozoa: Cheilostomata) by Aetea curta (Bryozoa: Cheilostomata)

Distal portions of zooids of uniserial, encrusting Aetea colonies curve abruptly away from the encrusted substratum. This characteristic, plus highly directional growth capability, enabled A. curta infesting an erect Cornucopina tuba colony to position its feeding structures consistently above the host colony, perhaps as a rheophilic growth response of individual zooids to feeding currents set up by the host.     

Novel characters in a conservative coral genus: three new species of Astreopora (Scleractinia: Acroporidae) from West Papua

Three new species of Astreopora (Hexacorallia: Scleractinia: Acroporidae), from Cenderawasih Bay in West Papua, exhibit morphological innovations for this conservative genus, extant since the Cretaceous. Two species are fully branching, a condition never previously described for Astreopora: Astreopora cenderawasih sp. nov. has dendritic branching, also seen in the confamilial genus Montipora, whereas branches of A. acroporina sp. nov. possess an axial corallite, regarded as the key morphological innovation facilitating rapid diversification and dominance of reefs in the younger, confamilial and most diverse genus Acropora (staghorn corals). We propose that these novel characters may be parallelisms indicating deep familial homologies. The third species, Astreopora montiporina sp. nov., has expansive coenosteum, reminiscent of plating Montipora. The new species form part of the most species-rich Astreopora assemblage reported to date, comprising 14 species. The unique tectonic and eustatic history of Cenderawasih Bay may have played a role in the evolution of these new species.     

Taxonomy of the arboreal polychaete Lycastopsis catarractarum Feuerborn (Namanereidinae: Nereididae), with a discussion of the feeding biology of the species

Lycastopsis catarractarum Feuerborn, 1931 is redescribed and a neotype designated. A full synonymy is given and all known records of the species are examined. Gut contents are analysed for two populations (Papua New Guinea and Fiji) and the feeding biology and ecology are discussed.     

Use of space by the marsupials Gracilinanus microtarsus (Gardner and Creighton, 1989) and Marmosops incanus (Lund, 1840) in an Atlantic Forest of southeastern Brazil

The use of space by animals is determined by environmental conditions, biological and ecological adaptations and interactions and mostly by resource availability. We sampled two species of Neotropical mammals to investigate their use of different strata in Atlantic Forest habitat in Brazil, as well as the home range sizes and movements of both sexes of each species. We found no difference in home ranges and movements between the sexes and species, but we found differences in the use of strata, with Gracilinanus microtarsus mostly using the canopy and Marmosops incanus using the ground. Gracilinanus microtarsus males mostly use the understorey in the wet season and the canopy in the dry season. We believe that these patterns of strata use reflect intrinsic characteristics of the species; and the shifts in resources and interspecific competition, which are lower in the dry season, seem to be responsible for the shifts in space use observed for G. microtarsus males. We recommend studies with spool-and-line techniques or radio tracking to further test refined hypotheses regarding the use of space, including the role of territoriality in females.     

The occurrence and phylogenetic implications of the ovipositor clip within the Figitidae (Insecta: Hymenoptera: Cynipoidea)

The presence of the ovipositor clip is surveyed throughout Figitidae. This morphological structure is postulated to restrain the parasitoid host during oviposition. All Figitinae and Eucoilinae that attack semi‐concealed dipterous hosts were found to possess the clip. Figitids that attack fully concealed hosts all lacked the ovipositor clip. It is hypothesized here that two subfamilies, the Anacharitinae and Aspicerinae, attack fully exposed hosts yet lack the clip in order to quickly oviposit and prevent fighting with the host. Mapping of the presence/absence of the ovipositor clip on to two competing phylogenies suggests this structure evolved in parallel in Figitinae and Eucoilinae. The evolution of the ovipositor clip is probably responsible for the successful colonization of semi‐concealed dipterous larvae by Eucoilinae.     

A survey of external morphology of mites of the superfamily Eupodoidea Banks, 1894 (Acari: Acariformes)

This paper represents the initial stage of a systematic study of the mite superfamily Eupodoidea Banks, 1894. For the first time a comprehensive account of external morphology is given with many structures being illustrated by scanning electron micrographs. Where homologies have been established, standardized notations are applied and compared with the terminology previously used by other authors.     

Ultrastructure of the pereopodal dactyls in the family Phronimidae Dana, 1852 (Crustacea: Amphipoda: Hyperiidea)

Species of the Phronimidae were studied for the micromorphology of their pereopods. Novel structures were found on the dactyls and are described in detail. A hypothesis is advanced that these structures serve also for external digestion and absorption of the tissues of their gelatinous plankton hosts.     

Occurrence and gut contents of flatworms on fungal sporocarps

Terrestrial flatworms of the family Rhynchodemidae were collected from fungal sporocarps. The frequency of flatworms on sporocarps differed among fungal species. Gut content analysis showed that the flatworms preyed upon fungivorous Collembola or other arthropods on the sporocarps. Fungal materials were observed in flatworm guts but only on the body surface and in the gut of Collembola prey. Basidiospores were observed on the surfaces of the flatworms.     

Observations on the morphology and classification of weevils (Coleoptera,Curculionoidea) with a key to major groups

A brief account of the present state of weevil taxonomy is followed by a detailed study of certain structures used in their classification, namely the venter, abdominal tergites, sternite 8 of the male, apex of the hind tibia and deciduous mandibular processes. A key to some 50 families and subfamilies of Curculionoidea is followed by a list of family-group taxa. The following changes are made: Brachyceridae, Erirhinidae, Cryptolaryngidae and Raymondionymidae are promoted to family rank from Curculionidae; Antliarhininae is demoted to a subfamily of Brentidae, and Allocoryninae to a subfamily of Oxycorynidae; Coptonotini is demoted to a tribe of Curculionidae-Scolytinae; Carinae, Subfam. n. is erected for Car Blackburn (genus incertae sedis) is Belidae; Dinomorphini is demoted to a tribe of Molytinae and Brachyceropsidinae is revived from synonymy with Dinomorphinae (Curculionidae); Brachyderini, Eremnini, Otiorhynchini and Sitonini are demoted to tribes of Entiminae; Desmidophorinae is transferred from Brentidae to Brachyceridae; Ocladiini is promoted to a tribe of Desmidophorinae (from Curculionidae-Cryptorhynchinae); Campyloscelini (including Phaenomerina) is transferred from Rhynchophoridae to Curculionidae-Zygopinae; Carphodicticinae is promoted to subfamily rank and transferred from Curculionidae-Scolytinae to Platypodidae; Perieges Schönherr is transferred from Curculionidae-Thecesterninae to Cryptolaryngidae and Agriochaeta Pascoe from Cryptorhynchinae to Hyperinae (Curculionidae); Schedlarius Wood and Mecopelmus Blackman are transferred from Coptonotidae to Platypodidae.     

A new species of Ameroseius Berlese from Brazil,redescriptions of Ameroseius plumosus (Oudemans) and Ameroseius plumigera (Oudemans) (Acari: Mesostigmata: Ameroseiidae) based on the examination of type material

Ameroseius Berlese is the most numerous genus of family Ameroseiidae Evans (in Hughes 1961). Species of this genus have been reported from many regions around the world. A few species of this genus are known from Brazil. Ameroseius mineiro Narita, Bernardi and Moraes, sp. nov. is described based on the morphology of adult females and males collected from guano in caves of Minas Gerais State, Brazil. This is the second Ameroseius species described from Brazil. The holotypes of Ameroseius plumosus (Oudemans) and Ameroseius plumigera (Oudemans) were examined, given their close similarity with the species described in this paper, and they are here redescribed. A key is provided to separate these and other most similar species. http://www.zoobank.org/urn:lsid:zoobank.org:pub:17A7D831-EC49-4D65-B06B-5E13EF52C696