scholarly journals Towards better management of Australia's shark fishery: genetic analyses reveal unexpected ratios of cryptic blacktip species Carcharhinus tilstoni and C. limbatus

2010 ◽  
Vol 61 (2) ◽  
pp. 253 ◽  
Author(s):  
J. R. Ovenden ◽  
J. A. T. Morgan ◽  
T. Kashiwagi ◽  
D. Broderick ◽  
J. Salini

The common blacktip shark (Carcharhinus limbatus) and the Australian blacktip shark (C. tilstoni) are morphologically similar species that co-occur in subtropical and tropical Australia. In striking contrast to what has been previously reported, we demonstrate that the common blacktip shark is not rare in northern Australia but occurs in approximately equal frequencies with the Australian blacktip shark. Management of shark resources in northern Australia needs to take account of this new information. Species identification was performed using nucleotide sequences of the control, NADH dehydrogenase subunit 4 (ND4) and cytochrome oxidase I (COI) regions in the mitochondrial genome. The proportion of overall genetic variation (FST) between the two species was small (0.042, P < 0.01) based on allele frequencies at five microsatellite loci. We confirm that a third blacktip species (C. amblyrhynchoides, graceful shark) is closely related to C. tilstoni and C. limbatus and can be distinguished from them on the basis of mtDNA sequences from two gene regions. The Australian blacktip shark (C. tilstoni) was not encountered among 20 samples from central Indonesia that were later confirmed to be common blacktip and graceful sharks. Fisheries regulators urgently need new information on life history, population structure and morphological characters for species identification of blacktip shark species in Australia.

Zootaxa ◽  
2020 ◽  
Vol 4851 (1) ◽  
pp. 189-197
Author(s):  
ARTHUR ANKER ◽  
MANAL AL-KANDARI ◽  
SAMMY DE GRAVE

The status of the common intertidal snapping shrimp, Alpheus inopinatus Holthuis & Gottlieb, 1958, is discussed based on newly collected material from Kuwait. Alpheus inopinatus was previously confused with morphologically very similar species in the Alpheus lobidens De Haan, 1849 species complex, formerly identified as A. crassimanus Heller, 1862 and herein tentatively referred to as A. cf. lobidens. The material herein examined strongly supports the validity of A. inopinatus based on several morphological characters, as well as differences in the colour pattern, compared to other members of the A. lobidens complex. 


2017 ◽  
Vol 191 ◽  
pp. 95-107 ◽  
Author(s):  
Jonathan J. Smart ◽  
Andrew Chin ◽  
Andrew J. Tobin ◽  
William T. White ◽  
Brian Kumasi ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mark de Bruyn ◽  
Matteo Barbato ◽  
Joseph D. DiBattista ◽  
Matt K. Broadhurst

AbstractIncreasing fishing effort, including bycatch and discard practices, are impacting marine biodiversity, particularly among slow-to-reproduce taxa such as elasmobranchs, and specifically sharks. While some fisheries involving sharks are sustainably managed, collateral mortalities continue, contributing towards > 35% of species being threatened with extinction. To effectively manage shark stocks, life-history information, including resource use and feeding ecologies is pivotal, especially among those species with wide-ranging distributions. Two cosmopolitan sharks bycaught off eastern Australia are the common blacktip shark (Carcharhinus limbatus; globally classified as Near Threatened) and great hammerhead (Sphyrna mokarran; Critically Endangered). We opportunistically sampled the digestive tracts of these two species (and also any whole prey; termed the ‘Russian-doll’ approach), caught in bather-protection gillnets off northern New South Wales, to investigate the capacity for DNA metabarcoding to simultaneously determine predator and prey regional feeding ecologies. While sample sizes were small, S. mokkaran fed predominantly on stingrays and skates (Myliobatiformes and Rajiformes), but also teleosts, while C. limbatus mostly consumed teleosts. Metabarcoding assays showed extensive intermixing of taxa from the digestive tracts of predators and their whole prey, likely via the predator’s stomach chyme, negating the opportunity to distinguish between primary and secondary predation. This Russian-doll effect requires further investigation in DNA metabarcoding studies focussing on dietary preferences and implies that any outcomes will need to be interpreted concomitant with traditional visual approaches.


IMA Fungus ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shan Shen ◽  
Shi-Liang Liu ◽  
Ji-Hang Jiang ◽  
Li-Wei Zhou

Abstract“Sanghuang” refers to a group of important traditionally-used medicinal mushrooms belonging to the genus Sanghuangporus. In practice, species of Sanghuangporus referred to in medicinal studies and industry are now differentiated mainly by a BLAST search of GenBank with the ITS barcoding region as a query. However, inappropriately labeled ITS sequences of “Sanghuang” in GenBank restrict accurate species identification and, to some extent, the utilization of these species as medicinal resources. We examined all available 271 ITS sequences related to “Sanghuang” in GenBank including 31 newly submitted sequences from this study. Of these sequences, more than half were mislabeled so we have now corrected the corresponding species names. The mislabeled sequences mainly came from strains utilized by non-taxonomists. Based on the analyses of ITS sequences submitted by taxonomists as well as morphological characters, we separate the newly described Sanghuangporus subbaumii from S. baumii and treat S. toxicodendri as a later synonym of S. quercicola. Fourteen species of Sanghuangporus are accepted, with intraspecific distances up to 1.30% (except in S. vaninii, S. weirianus and S. zonatus) and interspecific distances above 1.30% (except between S. alpinus and S. lonicerinus, and S. baumii and S. subbaumii). To stabilize the concept of these 14 species of Sanghuangporus, their taxonomic information and reliable ITS reference sequences are provided. Moreover, ten potential diagnostic sequences are provided for Hyperbranched Rolling Circle Amplification to rapidly confirm three common commercial species, viz. S. baumii, S. sanghuang, and S. vaninii. Our results provide a practical method for ITS barcoding-based species identification of Sanghuangporus and will promote medicinal studies and commercial development from taxonomically correct material.


Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 290
Author(s):  
Andrew M. Hosie ◽  
Jane Fromont ◽  
Kylie Munyard ◽  
Diana S. Jones

The subfamily Acastinae contains a diverse group of barnacles that are obligate symbionts of sponges and alcyonacean and antipatharian corals. Integrating morphological and genetic (COI) data to compare against known species, this paper reports on nine species of sponge-inhabiting barnacles of the subfamily Acastinae, including three undescribed species (Acasta caveata sp. nov., Euacasta acutaflava sp. nov., and E. excoriatrix sp. nov.) and three species previously not recorded in Australian waters (A. sandwichi, Pectinoacasta cancellorum, and P. sculpturata). The new species are distinguished from similar species by a suite of morphological characters as well as genetic distances. A lectotype for Pectinoacasta cancellorum is designated. Sponge hosts were identified for all specimens where possible and are represented by 19 species from eight families and five orders.


1973 ◽  
Vol 21 ◽  
pp. 3-7
Author(s):  
Helen Sawyer Hogg

The title of this talk is really just a different phrasing from one I have used at several IAU meetings on the subject of numbers and kinds of variables in globular clusters. To furnish this material, I have finished the Third Catalogue of Variables in Globular Clusters. Since many of you are coming to this Colloquium with new information, the Catalogue is in draft form with a request that corrections and additions be given me by October 2, after which the draft will go to the printer.The First Catalogue of Variables in Globular Clusters was published at this observatory in 1939 and the Second Catalogue in 1955. In 1966 appeared the excellent Catalogue of Variables South of Declination—29° by Fourcade, Laborde and Albarracin, with splendid large prints of identification charts.


Life ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 108
Author(s):  
Pedro María Alarcón-Elbal ◽  
Ricardo García-Jiménez ◽  
María Luisa Peláez ◽  
Jose Luis Horreo ◽  
Antonio G. Valdecasas

The systematics of many groups of organisms has been based on the adult stage. Morphological transformations that occur during development from the embryonic to the adult stage make it difficult (or impossible) to identify a juvenile (larval) stage in some species. Hydrachnidia (Acari, Actinotrichida, which inhabit mainly continental waters) are characterized by three main active stages—larval, deutonymph and adult—with intermediate dormant stages. Deutonymphs and adults may be identified through diagnostic morphological characters. Larvae that have not been tracked directly from a gravid female are difficult to identify to the species level. In this work, we compared the morphology of five water mite larvae and obtained the molecular sequences of that found on a pupa of the common mosquito Culex (Culex) pipiens with the sequences of 51 adults diagnosed as Arrenurus species and identified the undescribed larvae as Arrenurus (Micruracarus) novus. Further corroborating this finding, adult A. novus was found thriving in the same mosquito habitat. We established the identity of adult and deutonymph A. novus by morphology and by correlating COI and cytB sequences of the water mites at the larval, deutonymph and adult (both male and female) life stages in a particular case of ‘reverse taxonomy’. In addition, we constructed the Arrenuridae phylogeny based on mitochondrial DNA, which supports the idea that three Arrenurus subgenera are ‘natural’: Arrenurus, Megaluracarus and Micruracarus, and the somewhat arbitrary distinction of the species assigned to the subgenus Truncaturus.


Author(s):  
Dirk Erpenbeck ◽  
Merrick Ekins ◽  
Nicole Enghuber ◽  
John N.A. Hooper ◽  
Helmut Lehnert ◽  
...  

Sponge species are infamously difficult to identify for non-experts due to their high morphological plasticity and the paucity of informative morphological characters. The use of molecular techniques certainly helps with species identification, but unfortunately it requires prior reference sequences. Holotypes constitute the best reference material for species identification, however their usage in molecular systematics and taxonomy is scarce and frequently not even attempted, mostly due to their antiquity and preservation history. Here we provide case studies in which we demonstrate the importance of using holotype material to answer phylogenetic and taxonomic questions. We also demonstrate the possibility of sequencing DNA fragments out of century-old holotypes. Furthermore we propose the deposition of DNA sequences in conjunction with new species descriptions.


Gesture ◽  
2005 ◽  
Vol 4 (2) ◽  
pp. 157-195 ◽  
Author(s):  
Jennifer Gerwing ◽  
Janet Bavelas

Hand gestures in face-to-face dialogue are symbolic acts, integrated with speech. Little is known about the factors that determine the physical form of these gestures. When the gesture depicts a previous nonsymbolic action, it obviously resembles this action; however, such gestures are not only noticeably different from the original action but, when they occur in a series, are different from each other. This paper presents an experiment with two separate analyses (one quantitative, one qualitative) testing the hypothesis that the immediate communicative function is a determinant of the symbolic form of the gesture. First, we manipulated whether the speaker was describing the previous action to an addressee who had done the same actions and therefore shared common ground or to one who had done different actions and therefore did not share common ground. The common ground gestures were judged to be significantly less complex, precise, or informative than the latter, a finding similar to the effects of common ground on words. In the qualitative analysis, we used the given versus new principle to analyze a series of gestures about the same actions by the same speaker. The speaker emphasized the new information in each gesture by making it larger, clearer, etc. When this information became given, a gesture for the same action became smaller or less precise, which is similar to findings for given versus new information in words. Thus the immediate communicative function (e.g., to convey information that is common ground or that is new) played a major role in determining the physical form of the gestures.


Sign in / Sign up

Export Citation Format

Share Document