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1.
The four species included in the family Cryptacanthodidae are eel‐like, burrowing fishes distributed in the cold‐temperate coastal waters of the North Pacific and the western North Atlantic. This study describes the osteology and aspects of the ontogenetic skeletal development of two species, Cryptacanthodes maculatus from the western North Atlantic and C. aleutensis from the eastern North Pacific. We discuss the relationships of Cryptacanthodidae among other zoarcoid families. The Cryptacanthodidae have been previously included in the Stichaeidae, but removed and classified as a separate family based on the skull, pectoral radial, and cephalic lateral‐line morphology. Our observations (similarities in gill arch and pectoral girdle morphology; specifically, a thin sheet‐like flange of bone from the posterior margin of the supracleithrum) suggest a close relationship to at least some of the members of the family Stichaeidae. J. Morphol. 276:185–208, 2015. © 2014 Wiley Periodicals, Inc.  相似文献   

2.
Up to the present, the genus Leptostichaeus has been considered as belonging to subfamily Lumpeninae. A series of characters was analyzed for family and subfamily diagnostics within the group Stichaeidae. It was found that, in combination of all examined characters, the genus Leptostichaeus is either similar to Azygopterus or occupies an intermediate position between the latter and other members of the family Stichaeidae. The genus Leptostichaeus is transferred into the group Azygopterinae, which is revalidated as a subfamily within the family Stichaeidae.  相似文献   

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4.
Roe  Pamela  Norenburg  Jon L. 《Hydrobiologia》2001,456(1-3):133-144
A variety of pelagic nemerteans from our collections off California and Hawaii between 1992 and 1997 have a pair of epidermal structures, usually visible on the intact specimens, located on the ventro-lateral margins near the caudal end of the body. The only previous reports of similar structures from pelagic or any other nemerteans are for two species of the genus Plotonemertes. Histological serial sections of at least one specimen from each of about 16 morpho-species demonstrate that these are specialized glandular regions of the epidermis, which we broadly term postero-lateral glands. The objects of this study are to describe these glands at the level of light microscopy and to consider their systematic implications and possible functions. Most of the glands consist of two more or less spatially segregated types of secretory cells. One type is usually at the anterior end of the gland and resembles typical mucous goblet cells. The other type usually is the more abundant, and resembles a nemertean serous cell, with secretion that probably is relatively proteinaceous. The glands of one of the Plotonemertes specimens have two additional types of secretory cells that are relatively abundant. This study reports on postero-lateral glands from 30 specimens: three specimens of Plotonemertes in the family Protopelagonemertidae, 18 in at least three genera of the family Pelagonemertidae, six in the monotypic family Balaenanemertidae, and three of Proarmaueria in the family Armaueriidae. The glands are relatively large, with large quantities of secretory vesicles, indicating that they must be of considerable importance to the animals. However, neither structure nor location offer self-evident clues to function of these glands. We also report on different forms of regional specialization in the epidermis of Crassonemertes and Nectonemertes, both of which lack postero-lateral glands.  相似文献   

5.
Summary The snailfish family Liparididae was well represented in bottom trawl hauls (205–370 m) from the Spitsbergen area, with Liparis gibbus being the dominant species. Careproctus reinhardti was less numerous. The present paper is based on 539 specimens of C. gibbus (size range 6–25cm) and 120 specimens of L. reinhardti (size range 5–26 cm). Both species showed a rather similar size and age distribution. The stomach contents reveal that both snailfish species feed both benthically and pelagically. Crustaceans, especially amphipods and decapods, were the most common prey items. With increasing size of the fish, the decapod Pandalus borealis becomes more important, particularly for L. gibbus. Juvenile Liparis (1.3–4.3 cm in length) were found pelagically (35–200 m), and their diet mainly consisted of copepods and young hyperiid amphipods.  相似文献   

6.
The Graveldiver, Scytalina cerdale, is a small, poorly known burrowing fish from the intertidal and subtidal zones of the west coast of North America, ranging from south‐central California to Alaska. This is the sole member of the family Scytalinidae, which is included in the Zoarcoidei. Although it was described over 120 years ago, it is rare in natural history collections and its anatomy is only imperfectly known. This article describes and illustrates the skeletal anatomy of S. cerdale based on newly prepared cleared and stained specimens. Many points of its anatomy are clarified or corrected (e.g., presence of the intercalars and ribs, in contrast to their reported absence) or described for the first time (e.g., structure of its gill‐arches). Previous hypotheses of its systematic placement within the Zoarcoidei are discussed. On the basis of preliminary comparisons, S. cerdale may have phylogenetic affinity with at least some members of the family Stichaeidae (e.g., Xiphister). However, further study is needed on the anatomy and inter‐relationships of the families of the Zoarcoidei before any conclusions can be made. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

7.
Species concept and delimitation are fundamental to taxonomic and evolutionary studies. Both inadequate informative sites in the molecular data and limited taxon sampling have often led to poor phylogenetic resolution and incorrect species delineation. Recently, the whole chloroplast genome sequences from extensive herbarium specimen samples have been shown to be effective to amend the problem. Stachyuraceae are a small family consisting of only one genus Stachyurus of six to 16 species. However, species delimitation in Stachyurus has been highly controversial because of few and generally unstable morphological characters used for classification. In this study, we sampled 69 individuals of seven species (each with at least three individuals) covering the entire taxonomic diversity, geographic range, and morphological variation of Stachyurus from herbarium specimens for genome‐wide plastid gene sequencing to address species delineation in the genus. We obtained high‐quality DNAs from specimens using a recently developed DNA reconstruction technique. We first assembled four whole chloroplast genome sequences. Based on the chloroplast genome and one nuclear ribosomal DNA sequence of Stachyurus, we designed primers for multiplex polymerase chain reaction and high throughput sequencing of 44 plastid loci for species of Stachyurus. Data of these chloroplast DNA and nuclear ribosomal DNA internal transcribed spacer sequences were used for phylogenetic analyses. The phylogenetic results showed that the Japanese species Stachyurus praecox Siebold & Zucc. was sister to the rest in mainland China, which indicated a typical Sino‐Japanese distribution pattern. Based on diagnostic morphological characters, distinct distributional range, and monophyly of each clade, we redefined seven species for Stachyurus following an integrative species concept, and revised the taxonomy of the family based on previous reports and specimens, in particular the type specimens. Furthermore, our divergence time estimation results suggested that Stachyuraceae split from its sister group Crossosomataceae from the New World at ca. 54.29 Mya, but extant species of Stachyuraceae started their diversification only recently at ca. 6.85 Mya. Diversification time of Stachyurus in mainland China was estimated to be ca. 4.45 Mya. This research has provided an example of using the herbarium specimen‐based phylogenomic approach in resolving species boundaries in a taxonomically difficult genus.  相似文献   

8.
Molecular genetic study of genetic variations within COI, cytochrome b, and 16S rRNA of mitochondrial DNA in neck banded blenny Leptostichaeus pumilus, which was earlier assigned to the family Stichaeidae, indicates that the species is most close to a group combining the families Zoarcidae, Neozoarcidae, and Anarhichadidae. Significant genetic differences between neck banded blenny and the family Stichaeidae correspond to the level of divergence between other families of the suborder Zoarcoidei (Zaproridae, Ptilichthyidae, Pholidae, Cryptacanthodidae, and Bathymasteridae).  相似文献   

9.
Body size is among the most important biological variables but despite much measurement of this trait, the factors driving its variation are not fully understood. Here, I describe variation in body size in the damselfly Calopteryx maculata to establish whether variations in growth and development observed in response to experimental manipulation of temperature and time stress in the laboratory can be scaled‐up to variation among natural populations. Nine hundred and seven specimens of C. maculata males were collected from 34 sites across the species’ entire range in North America during the summer of 2010. A general measure of body size was derived from a series of wing and leg measurements. I compare the fit of models based on latitude (Bergmann’s rule), temperature (the temperature–size rule) and seasonal effects (a combination of temperature and time stress) using Akaike’s information criterion (AIC). The U‐shaped relationship between size and latitude was best explained by a seasonality model containing both photoperiod and temperature. The presence of both these terms suggests that time stress dominates in the southern part of the range, reducing body size by accelerating development. However, the temperature–size rule dominates in the northern part of the range, increasing body size closer to the northern range margin. The best‐fit model of geographic variation in size is in accordance with previous laboratory studies of temperature and photoperiod in damselflies and theoretical work, indicating that the findings from such studies can be applied to natural populations. These findings are likely applicable to any species with complex life histories inhabiting seasonal environments.  相似文献   

10.
Five finely preserved termites from the mid‐Cretaceous (Cenomanian) amber of Myanmar provide new information allowing a reanalysis of the phylogeny of basal termites. The Mastotermitidae family is recovered as monophyletic, and a redefined Hodotermitidae sensu lato is also monophyletic to include Archotermopsidae, Hodotermitidae and Stolotermitidae. Such a phylogenetic relationship agrees with the results from previous molecular phylogeny. Alongside these findings, there are many taxa that can only be shown to be termites with no other phylogenetically informative data. These form a comb of ‘grade groups’ emerging in the Late Jurassic. The new amber specimens are described as two new species. Anisotermes xiai gen. et sp.n. is described from multiple castes and has symplesiomorphic characteristics: large body size, a broad pronotum, well‐developed reticulated veins, and a large anal lobe of the hindwings. It shares wing features with the other new species, Mastotermes monostichus sp.n. Both new taxa are assigned to the Mastotermitidae, as they are shown to have synapomorphies that unite the family. This published work has been registered on ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:1AD5CECA‐27B7‐48D5‐88DC‐CEC5150962D7 .  相似文献   

11.
The Roach Rutilus rutilus (Linnaeus, 1758) (Pisces: Teleostei) is a widespread Eurasian cyprinid freshwater fish. Although numerous studies have investigated the species’ life history traits across its main native range of distribution, little is known from water bodies located beyond the southern limits of the latter, especially where the species has been introduced. Between July 2010 and April 2011, a total of 949 R. rutilus specimens was collected from Porsuk Reservoir (NW Turkey), and life-history traits of age, growth, fecundity and egg size were studied and compared to six other R. rutilus populations (including Caspian Roach R. r. caspicus) from the southern limits of distribution. The Porsuk population was characterised by relatively shorter lifespan, slower growth and lower fecundity. These findings support previous studies emphasising the importance of local environmental factors in shaping the life-history traits of widespread fish species. These must be taken into consideration especially in view of the potential value of R. rutilus as an economic resource for in-land fisheries.  相似文献   

12.
A new nematode,Paracapillaria xenentodoni n. sp. is described based on light microscope studies of the worms recovered from the migratory fishXenentodon cancila (Hamilton) from the Hooghly estuary at Kalyani, West Bengal, India. The worms are characterised by relatively large body size, the structure of the male caudal extremity (the presence of two wide, lobe-like, dorso-lateral caudal projections), the large size of the spicule (0.236–0.374 mm), the transversely wrinkled but non-spiny spicular sheath, the structure of the stichosome (30–40 stichocytes present), the slightly elevated anterior vulval lip, and the size (0.040–0.049 × 0.021–0.026 mm) and structure of the eggs. This represents the first species of the genusParacapillaria from India and also from fishes of the family Belonidae (Atheriniformes).  相似文献   

13.
No common opinion on the systematics position of species of the fishes of the subfamily Opisthocentrinae, Stichaeidae family has been formed up to the present. Therefore, a morphological analysis of fishes belonging to taxa Opisthocentrus ocellatus, O. tenuis, O. zonope, and Pholidapus dybowskii was undertaken. The obtained data treated by various methods of statistics implied the species independence of these taxa, which sympatrically occurred in the coastal areas of the northwest of the Sea of Japan. All the four studied species were similar in some attributes and distinct by other. Minor differences in the structure of the seismosensory system of Ph. dybowskii and Opisthocentrus species gave no basis on which to distinguish the independent genus Pholidapus. It would be correct to consider this as a subgenus of the Opisthocentrus genus, which includes three other species.  相似文献   

14.
Armoured scales (Hemiptera: Diaspididae) belong to the largest scale insect family and are among the most invasive insects in the world. Accurate identification of armoured scales is essential for systematic and phylogenetic studies; biogeography; trade and plant quarantine; and pest management, particularly biological control. Several species are serious pests of citrus. Records of past field surveys conducted in Viet Nam between 1967 and 2010 indicated the presence of 28 species on citrus there. Discrepancies in these records, and the retention of specimens of only five species in collections, led us to undertake surveys throughout the citrus-growing regions of the country in 2013 and 2014 to verify previous records and conserve voucher specimens. The presence of 21 diaspidid species was confirmed based on morphological and molecular data. The species observed were common but rarely abundant. Populations in commercial orchards may have been influenced by use of pesticides, but most species were recorded also in gardens and orchards where pesticide use was uncommon. Natural enemies were abundant, but were not thoroughly documented for all the diaspidids we observed. An identification key to the species collected is provided. Differences between our findings and previous records from Viet Nam, from Yunnan and Guangxi in China, and from Indochinese countries neighbouring Viet Nam, indicate the need for extensive surveys to fully document the diaspidid fauna on citrus in the region.  相似文献   

15.
Speciation and phenotypic plasticity are two extreme strategic modes enabling a given taxon to populate a broad ecological niche. One of the organismal models which stimulated Darwin's ideas on speciation was the Cirripedia (barnacles), to which he dedicated a large monograph. In several cases, including the coral-inhabiting barnacle genera Savignium and Cantellius (formerly Pyrgoma and Creusia, respectively), Darwin assigned barnacle specimens to morphological ``varieties' (as opposed to species) within a genus. Despite having been the subject of taxonomic investigations and revisions ever since, the significance of these varieties has never been examined with respect to host-associated speciation processes. Here we provide evidence from molecular (12S mt rDNA sequences) and micromorphological (SEM) studies, suggesting that these closely related barnacle genera utilize opposite strategies for populating a suite of live-coral substrates. Cantellius demonstrates a relatively low genetic variability, despite inhabiting a wide range of corals. The species C. pallidus alone was found on three coral families, belonging to distinct higher-order classification units. In contrast, Savignium barnacles exhibit large between- and within-species variations with respect to both micromorphology and DNA sequences, with S. dentatum ``varieties' clustering phylogenetically according to their coral host species (all of which are members of a single family). Thus, whereas Savignium seems to have undergone intense host-associated speciation over a relatively narrow taxonomic range of hosts, Cantellius shows phenotypic plasticity over a much larger range. This dichotomy correlates with differences in life-history parameters between these barnacle taxa, including host-infestation characteristics, reproductive strategies, and larval trophic type. Received: 18 January 1999 / Accepted: 9 May 1999  相似文献   

16.
A new species of Antarctoecia Ulmer, 1907 (Trichoptera: Limnephilidae) from south-eastern Brazil, Antarctoecia brasiliensis sp. nov., is described and figured based on adult male and female specimens from Mantiqueira mountain range, Minas Gerais State. This is the first record of the family Limnephilidae from Brazil.  相似文献   

17.
Fall rates of tumblers ofCombretum and of parachutes ofLeucadendron are shown to be generally high (> 1.8 ms–1). Tumblers contribute up to 77% of the mass of the dispersal unit and parachutes upto 22%. This implies that they are relatively expensive and inefficient in comparison with other propagule types. Morphometric analyses confirm previous findings that species with large seeds also have the largest dispersal structures, but the lowest dispersibility. Finally, there is a correlation between the sizes of these propagules and their associated leaf-size, confirming other studies that link the relative sizes of various plant attributes.  相似文献   

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Nuclear genome profiles were developed for representative species of the Gelidiales and Gracilariales using information from present and previous studies of cytogenetics, cytophotometry and DNA reassociation kinetics. Results indicate that species of Gracilaria and Gracilariopsis are characterized by distinct chromosome complements of n = 24 and n = 32, respectively, a narrow range of small genome sizes (2C = 0.35–0.45 pg) and a wide range of values for repeated and unique genome sequences. In contrast, the Gelidiales investigated are characterized by a wide range of chromosome complements, n = 6–29, a wider range of genome sizes (2C = 0.42–0.68 pg) and a large proportion of unique genome sequences. Nuclear genome sizes for species of the Gelidiales and Gracilariales are compared with estimates of other red algal orders including the Bangiales, Ceramiales and Gigartinales.  相似文献   

20.
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