Genetic variation in the soil phthiracarid mite, Steganacarus (S.) magnus (Nicolet, 1855) (Acarida, Oribatida) (Notulae Oribatologicae XL)

Genetic divergence and variability at 14 enzyme loci were examined in and between Italian populations of two edaphic Oribatid (Acarida, Oribatida) species, Steganacarus (Steganacarus) magnus (8 populations) and S. (S.) hirsutus (1 population). The seven populations belonging to S. (S.) magnus can be divided into two groups according to their phenotype, form anomala (A) (MON, ARG, AST, CDO) and form magna (M) (MAL, MAM, RIF) while another can be considered as hybrid between the two preceding groups (ZOC). Genetic identity (I) values between the S. (S.) magnus populations in spite of their morphological differences ranged from 0.977 to 1.000 showing the great genetic similarity of simple local populations while those of S. (S.) hirsutus indicated two distinct morphological species. The genetic distances between all the populations examined were very low despite the ecological differences and geographical distances between the collecting sites. Genetic variability estimates in all the populations of both species were very low when compared to those reported for most arthropods. Some explanatory considerations are suggested.     

A new species of Liropus (Crustacea, Amphipoda, Caprellidae) from Le Danois bank (southern Bay of Biscay)

A new species of the genus Liropus (Crustacea, Amphipoda, Caprellidae) is described based on specimens collected from Le Danois bank (‘El Cachucho’ fishing grounds), Bay of Biscay. Liropus cachuchoensis n. sp. can be distinguished from all its congeners mainly by the absence of eyes and by the presence of a dorsal projection proximally on pereonites 3, 4 and 5 in males, on 3 and 5 in females. The new species has been found living on muddy bottoms on the southern flank of the bank and adjacent continental slope, between 619 and 1062 m depth, with a maximum abundance (56.1 ind./100 m²) recorded at 1044–1062 m. Morphological comparisons among the world's members of Liropus, a key to species, and data on their distribution are presented.     

COI barcoding of true bugs (Insecta, Heteroptera)

Several recent studies have proposed that partial DNA sequences of the cytochrome c oxidase I (COI) mitochondrial gene might serve as DNA barcodes for identifying and differentiating between animal species, such as birds, fish and insects. In this study, we tested the effectiveness of a COI barcode to identify true bugs from 139 species collected from Korea and adjacent regions (Japan, Northeastern China and Fareast Russia). All the species had a unique COI barcode sequence except for the genus Apolygus (Miridae), and the average interspecific genetic distance between closely related species was about 16 times higher than the average intraspecific genetic distance. DNA barcoding identified one probable new species of true bug and revealed identical or very recently divergent species that were clearly distinguished by morphological characteristics. Therefore, our results suggest that COI barcodes can reveal new cryptic true bug species and are able to contribute for the exact identification of the true bugs.     

NEW SPECIES OF THAIS (NEOGASTROPODA, MURICIDAE) FROM SINGAPORE, WITH A RE-DESCRIPTION OF THAIS JAVANICA (PHILIPPI, 1848)

The intertimdal gastropod Thais malayensis n.sp. (Neogastropoda,Muncidae) is described from Singapore and peninsular Malaysia.Although a common species, it may have been previously overlookedor mistaken for other species found in and near mangroves. Anotherpoorly known species, T javanica (Phdippi) may also have beenconfounded with the new species. New data on their soft parts,radulae, opercula, and egg capsule morphology are presentedto distinguish between these closely related species. (Received 26 February 1996; accepted 15 May 1996)     

Environmental determinism,and not interspecific competition,drives morphological variability in Australasian warblers (Acanthizidae)

Interspecific competition is thought to play a key role in determining the coexistence of closely related species within adaptive radiations. Competition for ecological resources can lead to different outcomes from character displacement to, ultimately, competitive exclusion. Accordingly, divergent natural selection should disfavor those species that are the most similar to their competitor in resource use, thereby increasing morphological disparity. Here, we examined ecomorphological variability within an Australo‐Papuan bird radiation, the Acanthizidae, which include both allopatric and sympatric complexes. In addition, we investigated whether morphological similarities between species are related to environmental factors at fine scale (foraging niche) and/or large scale (climate). Contrary to that predicted by the competition hypothesis, we did not find a significant correlation between the morphological similarities found between species and their degree of range overlap. Comparative modeling based on both a priori and data‐driven identification of selective regimes suggested that foraging niche is a poor predictor of morphological variability in acanthizids. By contrast, our results indicate that climatic conditions were an important factor in the formation of morphological variation. We found a significant negative correlation between species scores for PC1 (positively associated to tarsus length and tail length) and both temperature and precipitation, whereas PC2 (positively associated to bill length and wing length) correlated positively with precipitation. In addition, we found that species inhabiting the same region are closer to each other in morphospace than to species outside that region regardless of genus to which they belong or its foraging strategy. Our results indicate that the conservative body form of acanthizids is one that can work under a wide variety of environments (an all‐purpose morphology), and the observed interspecific similarity is probably driven by the common response to environment.     

Long-term comparison of algal assemblages dominated by Cystoseira crinita (Fucales,Heterokontophyta) from Cap Corse (Corsica,North Western Mediterranean)

Species composition and abundance of present rocky shore assemblages at Cap Corse (Corsica, North Western Mediterranean) dominated by the fucalean alga Cystoseira crinita are compared with similar data obtained almost 50 years ago. Fifteen sites at five different localities where dense C. crinita assemblages were present in the past were revisited in June 2007. Possible differences between the two sampling times were investigated, applying various multivariate analysis techniques available in the statistical package PRIMER v.6. Dense assemblages dominated by C. crinita were found at 14 out of the 15 surveyed sites, showing a similar structure and composition to the assemblages studied in the past. PERMANOVA indicated slight differences in species composition and abundances between old and new surveys. These differences can be summarized as a higher abundance of encrusting species (up to 3?times greater cover), and more sciaphilic turf-forming species (3 to 60-fold greater, depending on the species) and Cladophora spp. (20?times greater) in the present study than in the old study. Furthermore, the present assemblages showed a lower abundance of photophilic turf-forming species. These differences could be due to different taxonomic competence between observers, seasonal fluctuations or long-term changes. Assemblages dominated by Cystoseira crinita in Cap Corse were confirmed to be common, as they were found and sampled at 22 new sites around the island.     

四川省山蚋亚属一新种记述(双翅目,蚋科)

继作者于2005年首次发现并记述四川省山蚋亚属二新种之后,报道四川省山蚋亚属另1新种,Simulium (Montisimulium)jiajinshanense sp.nov.(夹金山山蚋).本新种与报告自中国的S.(M.)tibetense Deng et al.,1993(西藏山蚋)and S.(M.)moxiense Chen et al.,2005(磨西山蚋),阿塞拜疆的S.(M.)assadovi(Djafarav,1956),亚美尼亚的S.(M.)litshkense(Rubtsov,1947),哈萨克斯坦的S.(M.)quattuordecimfiatliatum(Rubtsov,1947)和塔吉克斯坦的S.(M.)quattuordecimfilum Rubtsov,1947相似,均具14条呼吸丝,但新种可依据食窦弓具中突,两性生殖器的特殊形态,茧简单和呼吸丝特殊分枝等综合特征和上述近缘种相区别.     

Two new Aggregata species (Apicomplexa: Aggregatidae) infecting Octopus tehuelchus and Enteroctopus megalocyathus (Mollusca: Octopodidae) in Patagonia, Argentina

During a long-term study carried out between 1981 and 1996 on the biological and fishery aspects of octopuses inhabiting the Gulfs of San Matías, San José, and Nuevo, Patagonia, Argentina, 2 new species of Aggregata (Apicomplexa: Aggregatidae) were found in the digestive tracts of Octopus tehuelchus d'Orbigny, 1834 (prevalence 72%) and Enteroctopus megalocyathus (Gould, 1852) (prevalence 77%). Both species can be distinguished from other congeners on the basis of their hosts, the diameters of sporocysts, and number and length of sporozoites. Despite overlap in the distributions of the two hosts species in the area covered in this study, both Aggregata new species exhibited high host specificity.     

Multivariate analyses of morphometrical features from Apatemon gracilis (Rudolphi, 1819) Szidat, 1928 and A. annuligerum (v. Nordmann, 1832) (Digenea: Strigeidae) metacercariae

Only two species of the strigeid subgenus Apatemon (Apatemon) sensu Sudarikov (1959), Apatemon gracilis (Rudolhi, 1819) and A. annuligerum (von Nordmann, 1832), are known to infect British fishes. A. annuligerum is poorly characterised, with few life-cycle data available, since only the adult and metacercarial stages have been described. Both of these life-stages demonstrate only minor morphological differences from those of A. gracilis. The multidimensional approach of principal components analysis (PCA) was employed to determine the intra- and inter-specific morphological variation that exists for metacercariae of these species. Analyses revealed that metacercarial morphometrics cannot confidently discriminate between Apatemon gracilis and A. annuligerum specimens. Indeed, levels of intra-specific variation present between A. gracilis metacercariae originating from different piscine hosts were as marked for certain populations as those between the two nominal species. Individual populations of A. gracilis metacercariae differed most in the relative dimensions of their internal organs, whereas variation between the two nominal species was primarily in length-related variables. A. gracilis specimens originating from Welsh and Scottish stoneloach represented two populations with the most comparable total body lengths, yet clustered separately. Conversely, A. gracilis metacercariae infecting rainbow trout and salmon parr differed markedly in size, but demonstrated minimal composite morphological variation. Much, if not all, of the variation described between populations and species of parasites can be attributed to host or to metacercarial location within a particular host. These findings and the lack of strong life-cycle data for A. annuligerum place some doubt on its validity as a species discrete from A. gracilis.     

广东产轴鳞蕨属(叉蕨科) 植物

基于馆藏标本的研究, 确认广东产3 种轴鳞蕨属植物: 异鳞轴鳞蕨Dryopsis heterolaena、泡鳞轴鳞蕨D. mariformis 和阔鳞轴鳞蕨D. maximowicziana , 其中泡鳞轴鳞蕨和阔鳞轴鳞蕨为广东新记录的蕨类。澄清广东不产顶果轴鳞蕨D. apiciflora , 最近出版的《广东植物志》第七卷记载的顶囊肋毛蕨Ctenitis apiciflora ( 即顶果轴鳞蕨D. apiciflora) , 系异鳞轴鳞蕨的错误鉴定。文中列有分种检索表、种的文献引证、标本引证、生境与分布资料。     

Dryopsis ( Tectariaceae) in Guangdong,China

Based on herbaria collections, three species of the fern genus Dryopsis ( Tectariaceae ) are recognized from Guangdong Province, China . They are D. heterolaena , D. mariformis and D. maximowicziana . Among the three species, D. mariformis and D. maximowicziana are new records to Guangdong . In the newly published book , Flora of Guangdong Volume VII , the name Ctenitis apiciflora (Wall . ex Mett .) Ching ( = D. apiciflora (Wall . ex Mett .) Holttum & Edwards) instead of D. heterolaena is recorded due tomisidentification . The morphological and ecological differences between D. heterolaena and D. apiciflora are discussed . A key to the three species, habitat and distribution data on the three species are given .     

Morphological, allozymic, and karyotypic distinctions between Neritina (Dostia) violacea and N. (D.) cornucopia (Gastropoda: Neritoidea)

Two species of mangrove gastropod, Neritina (Dostia) violacea Gmelin, 1791 and N. (D.) cornucopia Benson, 1836, from Hong Kong have been compared morphologically, allozymically, and karyotypically. The two can be identified by differences in shell pigmentation patterns, ventral shell characters, and radular teeth characters. Allozymic variations at 15 presumptive gene loci were examined. Average heterozygosities were 0.058 in local populations of N. (D.) violacea and 0.138 in N. (D.) cornucopia. Six enzyme encoding loci were typically diagnostic for individuals of each species and no hybrid patterns have been recorded. Nei's standard genetic distance and genetic identity between the two species were estimated to be 0.814 and 0.443, respectively. Karyotypic investigations have revealed that both species are diplonts, with two X-chromosomes in females and one in males. Diploid numbers are 2n = 20 + XX (or XO) for N. (D.) violacea and 2n = 26 + XX (or XO) for N. (D.) cornucopia.     

Genetic,ecological, and behavioural divergence between two sibling snapping shrimp species (Crustacea: Decapoda: Alpheus)

Examination of genetic and ecological relationships within sibling species complexes can provide insights into species diversity and speciation processes. Alpheus angulatus and A. armillatus, two snapping shrimp species with overlapping ranges in the north-western Atlantic, are similar in morphology, exploit similar ecological niches and appear to represent recently diverged sibling species. We examined phylogenetic and ecological relationships between these two species with: (i) sequence data from two mitochondrial genes (16S rRNA and COI); (ii) data on potential differences in microhabitat distribution for A. armillatus and A. angulatus; and (iii) data from laboratory experiments on the level of reproductive isolation between the two species. DNA sequence data suggest A. armillatus and A. angulatus are sister species that diverged subsequent to the close of the Isthmus of Panama, and that haplotype diversity is lower in A. armillatus than in A. angulatus. Both species are distantly related to A. heterochaelis and A. estuariensis, two species with which A. angulatus shares some similarities in coloration. Ecological data on the distribution of A. angulatus and A. armillatus from two locations revealed differences in distribution of the two species between habitat patches, with each patch dominated by one or the other species. However, there was no apparent difference in distribution of the two species within habitat patches with respect to microhabitat location. Ecological data also revealed that heterospecific individuals often occur in close proximity (i.e. within metres or centimetres) where sympatric. Behavioural data indicated that these species are reproductively isolated, which is consistent with speciation in transient allopatry followed by post-divergence secondary contact. Our data further resolve taxonomic confusion between the sibling species, A. armillatus and A. angulatus, and suggest that sympatry in areas of range overlap and exploitation of similar ecological niches by these two recently diverged species have selected for high levels of behavioural incompatibility.     

广东产轴鳞蕨属(叉蕨科)植物

基于馆藏标本的研究,确认广东产3种轴鳞蕨属植物:异鳞轴鳞蕨Dryopsis heterolaena、泡鳞轴鳞蕨D·mariformis和阔鳞轴鳞蕨D·maximowicziana,其中泡鳞轴鳞蕨和阔鳞轴鳞蕨为广东新记录的蕨类。澄清广东不产顶果轴鳞蕨D·apiciflora,最近出版的《广东植物志》第七卷记载的顶囊肋毛蕨Ctenitis apiciflora(即顶果轴鳞蕨D·apiciflora) ,系异鳞轴鳞蕨的错误鉴定。文中列有分种检索表、种的文献引证、标本引证、生境与分布资料。     

Mammals as hosts of Ixodid ticks (Acarina,Ixodidae)

Trophic association between adult ticks of the world fauna with their mammal hosts (511 tick species out of 650 species of Ixodidae of the world fauna) are reviewed. Specific tick species parasitize on representatives of 22 (out of 27) mammal orders, but species of Paucituberculata, Notoryctemorphia, Peramelemorphia, Scandentia, and Dermoptera have no specific parasites. The highest number of tick species was recorded from Artiodactyla and rodents. Mammals, on which representatives of all the 14 genera of the family parasitize, provide the diversity of the ixodid tick fauna. The conclusion on the priority of ecological factors in comparison with phylogenetic status of hosts in the formation of specific characteristics of ticks confirms Balashov’s (1982) concept on the character of host-parasite association between ticks and mammals.     

Characterization of feeding habits,prey diversity and diet overlap of two sympatric species: Bronze catfish,Netuma bilineata (Valenciennes, 1840) and blacktip sea catfish,Plicofollis dussumieri (Valenciennes, 1840) in the northern Arabian Sea

This study describes the diet composition, diet overlap and prey diversity in two economically and ecologically important marine catfish species: the bronze catfish (Netuma bilineata) and the blacktip sea catfish (Plicofollis dussumieri) collected between January and December 2015 from the northern Arabian Sea coast of Pakistan. Stomach data of 342 bronze catfish and 283 blacktip sea catfish were examined. Diet composition and feeding strategy of each species by identification of stomach contents were weighed and enumerated. Both species primarily consumed teleosts, Brachyura and small amounts of a wide variety of prey items; however, specialization was a more common trait for the bronze catfish than for the black tip sea catfish. The Morisita‐Horn index showed considerable diet overlap in percentage of mean weights (0.847) than in numbers (0.612) between co‐prey pairs of both species. The highest Bray‐Curtis similarity between the southwest monsoon (SWM) and south inter monsoon (SIM) was observed in bronze catfish and lowest between autumn inter monsoon (AIM) seasons in both species. While Bray‐Curtis dissimilarity was observed, both species share diet niches and diet overlap. The present study evaluation of the feeding strategy and potential competition between two sympatric species of marine catfishes can provide the framework for their conservation and management in the region.     

Biometric variability of Hadwenius tursionis (Marchi, 1873) (Digenea,Campulidae) from the intestine of the bottlenose dolphin Tursiops truncatus (Montagu, 1821)

The species discrimination in the family Campulidae is largely based on morphometric characters (absolute measurements and ratios). To assess the variability of this characters we have studied the campulid species Hadwenius tursionis from four Mediterranean bottlenose dolphins Tursiops truncatus from the Western Mediterranean. In H. tursionis most absolute measurements differed significantly across the infrapopulations, showing high coefficients of variation. Only egg dimensions appeared to be fairly conservative. Body ratios were less variable than absolute measurements, but growth patterns did vary significantly between the infrapopulations studied. None of the ratios previously used in relation to other species of the family Campulidae indicated either isometric or allometric growth in this case. Only the ratios concerning the size of the gonads and the shape of the gonads and suckers showed isometry. It is concluded that absolute measurements and ratios should be used with caution in relation to the separation of species of the family Campulidae unless their intrinsic variability can be established beforehand.