Novel micromorphological characters in combination with molecular studies have led to an extensive revision of the taxonomy and systematics of scleractinian corals. In the present work, we investigate the macro- and micromorphology and the phylogenetic position of the genera Australomussa and Parascolymia, two monotypic genera ascribed to the family Lobophylliidae. The molecular phylogeny of both genera was addressed using three markers, the partial mitochondrial COI gene and the nuclear histone H3 and the ribosomal ITS region. Based on molecular data, Australomussa and Parascolymia belong to the Lobophylliidae and they cluster together with the genera Lobophyllia and Symphyllia within the same clade. While A. rowleyensis and P. vitiensis are closely related based on the three gene regions examined, their macro and micromorphology suggest that these species are distinct, differing in several characters, such as continuity and thickness of the costosepta, the number of septa, septal tooth height, spacing, and shape, and the distribution and shape of granules. Thus, we revise the taxonomic status of the genus Australomussa as a junior synonym of Parascolymia.
Roberto Arrigoni, Zoe T. Richards, Chaolun Allen Chen, Andrew H. Baird and Francesca Benzoni
Edited by R.W.M. van Soest
Łukasz Depa, Mariusz Kanturski, Artur Taszakowski and Karina Wieczorek
Edited by M. Schilthuizen
Firm matching of genitals during copulation is of critical importance to effective insemination and thus, gene flow. During the evolution of insects, an effective position during copulation promoted higher fecundity through control over the act of mating or elimination of competitors. Usually during insect copulation, either twisting or flexing of the male abdomen occurs, and genitals remain symmetrically or asymmetrically disposed following changes in the mating position. However, it is always the dorsal side of the male genitalia that makes contact with the ventral side of female abdomen. Here we present the unusual case of a ‘belly-to-belly’ copulation, with symmetrically positioned male genitals and no twisting of the abdomen. During the mating of two species in the Stomaphis genus of large, tree dwelling aphids, the dwarfish male is attached to the underside of the female, with the ventral part of its genitals contacting the ventral part of female abdomen, and the aedeagus effectively inserted into the female genital organs. Interestingly, congeneric species do not exhibit this sort of mating, but differences in the genital plates of females, between species, may play an important role. These observations raise many questions concerning the possible dominant role of the female during mating and later, during mate guarding by male, which can lead to monandry in this generally polyandrous group of insects. It is possible that this sort of mating is either an adaptation to the competitive behaviour of other males or a consequence of the obligatory mutualistic relationship with ants, and the adaptation to specialised ecological niches enforced by this relationship. If ants do influence the mating habits of Stomaphis then it is possible that speciation in this group of insects, and phytophagous insects generally, is partially driven by their relationship with ants.
Carolin Haug and Joachim T. Haug
Edited by R. Vonk
We describe a possible new defensive behaviour of larval stages of mantis shrimps (Stomatopoda). Mantis shrimp larvae are rarely observed in nature, thus the study is based on postures of museum material and functional morphological aspects. Specimens described here are tightly enrolled, their pleon is bent forward, and the telson is locked into the frontal margin of the shield. This margin has two lobes into which the two posterolateral spines of the telson fit. The shield shows further adaptions to enrolment; e.g., the ventral gape of the shield perfectly matches the width of the pleon and leaves no major gaps when the pleon is bent forward. Based on these observations, we briefly discuss the possibilities to infer behavioural aspects from functional morphological aspects. Enrolment in modern day organisms is primarily known from terrestrial arthropods, e.g., pill bugs and pill millipedes, but in the Palaeozoic it was mainly performed by marine organisms such as trilobites, agnostines and their relatives. Stomatopod larvae that appear to be able to perform enrolling in a marine environment are therefore a potential functional equivalent for better understanding the functional aspects of enrolment in extinct marine arthropods.
Giuliano Greco, Marco Faimali and John Davenport
Edited by R. Vonk
During its life cycle Carcinus maenas (Decapoda, Portunidae) goes through several phases of the moulting process (ecdysis) which allow it to grow despite having a rigid, non-living outer surface. As an individual approaches ecdysis, the exoskeletal calcium is solubilized (decalcification) from the shell and transferred through the integumentary epithelium to the blood, where much of it is transported to cells, tissues and organs of temporary storage where it is later mobilized for deposition into the new exoskeleton. We hypothesised that the decalcification process caused deterioration of the features and structures (e.g. tubercles and setae) characterizing the crab carapace, but that this can be reversed by moulting. We also tested whether wear and tear caused by abiotic and biotic influences between moults might also cause surface deterioration. Any such deterioration would be detrimental to C. maenas. For example, compromise of the function of these structures could influence the settlement rate of epibionts on the crab surface as well as interfering with sensory and regulatory physiology. In this study, animals characterized as intermoult, premoult and postmoult crabs, were selected and their carapace surfaces analysed to evaluate the relationship between deterioration and moulting stage. Data showed that the outer surfaces of Carcinus maenas were subject to deterioration of their fine microtopographies throughout their life, probably influencing epibiotic settlement. Furthermore, the moulting process, already recognized as crucial for growth and removal of fouling epibionts, also proved to be necessary for the periodic restoration of surface microtopography. These findings, besides providing new insights into details of the crab life cycle, indicate a likely antifouling property for carapace microtopography in C. maenas.During its life cycle Carcinus maenas (Decapoda, Portunidae) goes through several phases of the moulting process (ecdysis) which allow it to grow despite having a rigid, non-living outer surface. As an individual approaches ecdysis, the exoskeletal calcium is solubilized (decalcification) from the shell and transferred through the integumentary epithelium to the blood, where much of it is transported to cells, tissues and organs of temporary storage where it is later mobilized for deposition into the new exoskeleton. We hypothesised that the decalcification process caused deterioration of the features and structures (e.g. tubercles and setae) characterizing the crab carapace, but that this can be reversed by moulting. We also tested whether wear and tear caused by abiotic and biotic influences between moults might also cause surface deterioration. Any such deterioration would be detrimental to C. maenas. For example, compromise of the function of these structures could influence the settlement rate of epibionts on the crab surface as well as interfering with sensory and regulatory physiology. In this study, animals characterized as intermoult, premoult and postmoult crabs, were selected and their carapace surfaces analysed to evaluate the relationship between deterioration and moulting stage. Data showed that the outer surfaces of Carcinus maenas were subject to deterioration of their fine microtopographies throughout their life, probably influencing epibiotic settlement. Furthermore, the moulting process, already recognized as crucial for growth and removal of fouling epibionts, also proved to be necessary for the periodic restoration of surface microtopography. These findings, besides providing new insights into details of the crab life cycle, indicate a likely antifouling property for carapace microtopography in C. maenas.
Pablo Hernández-Alcántara and Vivianne Solís-Weiss
Edited by H.A. ten Hove
The morphological and morphometric analyses of 88 orbiniids from the continental shelf of the Gulf of California lacking thoracic neuropodial hooks confirmed that a new species, Leitoscoloplos multipapillatus, described herein, is present along with Leitoscoloplos panamensis (Monro. 1933), already recorded there. The new species is closely related to L. panamensis, but can be clearly separated from this, and all other species of Leitoscoloplos, by the unique presence of up to 14 stomach papillae per chaetiger. A third taxon was identified, Leitoscoloplos sp., which is morphologically indistinguishable from L. panamensis, except for the presence of 1-2 stomach papillae on 1-2 segments, a feature that although important was not considered significant enough to erect a new species. Morphometric analyses between the closely related species, L. panamensis (including its type material) and L. multipapillatus sp. nov., in addition to Leitoscoloplos sp., were used to verify the new species. The generic diagnosis is emended to include species with numerous stomach papillae. Anatomical examination of these species was carried out with SEM to illustrate their characteristic features and corroborate the presence of capillary chaetae only along the thorax of the analysed specimens, as well as the unusual occurrence of stomach papillae.
José M. Serrano, César A. Berlanga-Robles and Arturo Ruiz-Luna
Edited by B.M. Wielstra
Amphibian diversity and distribution patterns in Sinaloa state (north-western Mexico) were assessed from the Global Amphibian Assessment database (GAA-2010). A geographic information system (GIS) was used to evaluate diversity based on distribution maps of 41 species, associated with environmental data. The highest α and γ-diversities were identified in the south-eastern portion of the state, in mountain zones with a warm sub-humid climate, whereas the greatest β-diversity (multiplicative formulation) was aggregated in patches in the western portion of the state in mountains with temperate climates. A cluster analysis and Mantel test showed a strong association of Sorensen’s dissimilarity (additive formulation of β-diversity) with climate and soil moisture categories rather than physiographic categories. Additionally, the partition of Sorensen´s dissimilarity into its components (turnover and nestedness) showed a gradient of species turnover related to contrasting climate units and a marked pattern of nestedness between the middle mountains and the coastal plain. The results of the study suggest that the highest α and β-diversity values occur in the middle-humidity range as well in the transitional-climate categories. This pattern is unusual for amphibian distributions because the highest global and regional amphibian diversities are typically related to high humidity values and climate stability (warm and wet most of the year). This particular pattern, occurring in a transitional area, encourages further biological and ecological studies to clarify the status of amphibian populations and support conservation measures.
Loretta Guidi, M. Antonio Todaro, Marco Ferraguti and Maria Balsamo
Edited by R. Sluys
The reproductive system and the spermatozoon of Megadasys sterreri from Lanzarote (Canary Islands, Spain) were studied at structural and ultrastructural levels. The species is a simultaneous hermaphrodite with cross-fertilization and shows paired gonads, the male anterior and the female posterior, and both gametes mature in a caudo-cephalic direction. Sperm ducts converge on the midline and open into a ventral common pore. Two sexual accessory organs are present in the caudal trunk. A pipe-like frontal organ lies between the ovaries and the caudal organ, and is composed of a long, thin region connected to a large zone containing mature and degenerating spermatozoa. The cigar-like caudal organ is elongate, bulky and is made of an anterior glandulo-muscular region and a posterior muscular one. Spermatozoa are long, filiform cells formed by an acrosome, a nucleus-mitochondrial complex, and a flagellum. The long acrosome is composed of an apical twisted region and a basal straight region. The nucleo-mitochondrial complex is formed by a spring-shaped nucleus surrounding basally the mitochondrion and apically a granular material. The flagellum has a 9x2+2 axoneme, characterized by a dense and prominent central sheath surrounding the central tubules. Megadasys sterreri (Cephalodasyidae) shows the same reproductive layout as Crasiella (Planodasyidae): paired gonads, caudo-cephalic maturation of gametes, sperm ducts converging into a common ventral pore, and two sexual accessory organs. Also the spermatozoa ultrastructure shows two similarities in the two genera: a peculiar prominent central sheath in the axoneme and a similar structure of the basal region of the acrosome. Considering the likely polyphyletic nature of the family Cephalodasyidae, and the sister- taxon relationship of Megadasys and Crasiella that emerged from a recent molecular phylogenetic study, a close relationship between the two taxa appears to be very likely; consequently, we propose to remove Megadasys from the family Cephalodasyidae and affiliate it to the family Planodasyidae.
Edited by J.W. Arntzen
Compared with the elongate bodies of shrimps or lobsters, crabs are characterised by a compact body organisation with a depressed, short carapace and a ventrally folded pleon. The evolutionary transformation from a lobster-like crustacean towards a crab is called ‘carcinization’ and has been interpreted as a dramatic morphological change. Nevertheless, the crab-shape evolved convergently in a number of lineages within Decapoda. Accordingly, numerous hypotheses about internal and external factors have been presented, which all try to explain these frequent convergent carcinization events despite the seemingly fundamental changes in the body organisation. However, what a crab is lies greatly in the eye of the beholder and most of the hypotheses about the lobster/crab transformation are biased by untested assumptions. Furthermore, there are two meanings of the word ‘crab’ within decapods: one, the phylogenetic meaning, refers to the clade Brachyura; the other, more general and typological use of the word crab, describes decapods with a certain body shape. These two meanings should not be confused when the issue of carcinization is discussed. Here, I propose a definition of what a crab is, i.e. what is meant when we speak about carcinization. I show that not all Brachyura are crabs in the typological sense. Carcinization occurred at least twice within the clade. Among Anomala there is further evidence that crab-shaped Lithodidae derived from a hermit-crab like ancestor. Carcinization is not restricted to Anomala plus Brachyura (Meiura) but is also found in Achelata, namely in slipper lobsters. A deconstruction of the crab-shape reveals that parts of it appear in various combinations among all decapod groups. Only a certain threshold of number and quality of crab-features makes us call an animal a ‘crab’. This reveals that carcinization does not involve such dramatic changes in morphology as has been suggested. Moreover similar alterations of body shapes appear frequently in other crustacean taxa and in various animal groups as diverse as sharks and sea urchins. Hence morphological constraints, macroevolution, trends, tendencies, or underlying synapomorphies of any kind are not necessary assumptions for the explanation of the evolution of crabs.
Lucy A. Taylor, Dennis W.H. Müller, Christoph Schwitzer, Thomas M. Kaiser, Daryl Codron, Ellen Schulz and Marcus Clauss
Edited by V. Nijman
Tooth wear can affect body condition, reproductive success and life expectancy. Poor dental health is frequently reported in the zoo literature, and abrasion-dominated tooth wear, which is typical for grazers, has been reported in captive browsing ruminants. The aim of this study was to test if a similar effect is evident in captive rhinoceros species. Dental casts of maxillary cheek teeth of museum specimens of captive black (Diceros bicornis; browser), greater one-horned (Rhinoceros unicornis; intermediate feeder) and white rhinoceroses (Ceratotherium simum; grazer) were analysed using the recently developed extended mesowear method for rhinoceroses. Captive D. bicornis exhibited significantly more abrasion-dominated tooth wear than their free-ranging conspecifics (p<0.001), whereas captive C. simum exhibited significantly less abrasion-dominated tooth wear, particularly in the posterior cusp of the second molar (p=0.005). In R. unicornis, fewer differences were exhibited between free-ranging and captive animals, but tooth wear was highly variable in this species. In both free-ranging and captive D. bicornis, anterior cusps were significantly more abrasiondominated than posterior cusps (p<0.05), which indicates morphological differences between cusps that may represent functional adaptations. By contrast, tooth wear gradients between free-ranging and captive animals differed, which indicates ingesta- specific influences responsible for inter-tooth wear differences. Captive D. bicornis exhibited more homogenous tooth wear than their free-ranging conspecifics, which may be caused by an increase in the absolute dietary abrasiveness and a decrease in relative environmental abrasiveness compared to their freeranging conspecifics. The opposite occurred in C. simum. The results of this study suggest that diets fed to captive browsers are too abrasive, which could result in the premature loss of tooth functionality, leading to reduced food acquisition and processing ability and, consequently, malnourishment.
Mansour Aliabadian, Vincent Nijman, Ahmad Mahmoudi, Mehdi Naderi, Ronald Vonk and Miguel Vences
Edited by J.W. Arntzen
In the context of DNA Barcoding, sequences of standard marker genes for thousands and potentially millions of individuals and species are becoming available, requiring ever more efficient bioinformatic environments and software algorithms for analysis. We here present ExcaliBAR (Extraction, Calculation, Barcoding), a user-friendly software utility to facilitate one important initial step in DNA barcoding analyses, namely the determination of the barcoding gap between pairwise genetic distances among and within species, based on original distance matrices computed by MEGA software. In addition, the software is able to rename sequences downloaded via the standard user interfaces of public databases such as GenBank, without the need of developing and applying specific scripts for this purpose.