Bathymetric Distribution of Sea Stars (Asteroidea) off the Northern Oregon Coast

1966 ◽  
Vol 23 (11) ◽  
pp. 1673-1714 ◽  
Author(s):  
Miles S. Alton
Keyword(s):  
Atomic Energy Commission ◽  
Abundant Species ◽  
Sea Star ◽  
Sea Stars ◽  
Faunal Assemblages ◽  
Number Of Species ◽  
Northeastern Pacific ◽  
Abyssal Zone ◽  
Abyssal Fauna ◽  
Shallow Water Species

During U.S. Bureau of Commercial Fisheries' Atomic Energy Commission trawling investigations in waters adjacent to the mouth of the Columbia River, a total of 54 species and one subspecies of sea stars was collected from bottom depths of 50–1050 fath. The sea stars in the area of study can be divided into four faunal assemblages by benthic zones: (1) an outer sublittoral fauna (50–108 fath) consisting of several shallow-water species, some of which have their apparent maximum depth of occurrence in this zone. The number of species and the availability of sea stars per hour of trawling is much lower in this zone compared to the other benthic zones in the study area; (2) an upper bathyal fauna (122–258 fath) consisting of several species having either a continuous or discontinuous circumboreal distribution; (3) a lower bathyal fauna (275–500 fath) characterized by a large number of species and a high availability of sea stars in terms of numbers and weight per hour of trawling. Several of the more frequently occurring and abundant species in this zone belong to genera endemic to the northeastern Pacific; and (4) an abyssal fauna (900–1050 fath) consisting almost entirely of species belonging to cosmopolitan genera.The bathyal-abyssal zone (585–850 fath) is considered a zone of transition because of the intrusion into this zone of elements of the sea star fauna from both the lower bathyal and the abyssal.

scholarly journals Arm Deflation in the Rare Thorny Sea Star, Poraniopsis inflatus (Asteroidea: Poraniidae), A Defensive Response to other Sea Stars?

2010 ◽  
Vol 124 (3) ◽  
pp. 199
Author(s):  
Roland C. Anderson ◽  
Ronald L. Shimek
Keyword(s):  
Coelomic Fluid ◽  
Defensive Response ◽  
Sea Star ◽  
Sea Stars ◽  
Defensive Reaction ◽  
Northeastern Pacific

The Thorny Sea Star, Poraniopsis inflatus, is rare in the Northeastern Pacific. It lacks pedicellariae or other overt defenses for protection against other predatory sea stars. During an earlier study, a P. inflatus confronted by an asteroid-eating sea star was observed to exhibit a possible defensive reaction: "arm deflation." It was 15 years before another P. inflatus specimen could be obtained and that hypothesis confirmed by testing with individuals of 18 other sea-star species. Contact with individuals of four predatory sea-stars, Asterina miniata, Crossaster papposus, Solaster dawsoni, and Pycnopodia helianthoides, elicited the reaction in the P. inflatus. The specimen collapsed ("deflated") an arm closest to the predatory star, possibly by expelling coelomic fluid, exposing more of its embedded thorns (hence its common name) which may discourage other sea stars from attempting to eat it.

scholarly journals Sea stars generate downforce to stay attached to surfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mark Hermes ◽  
Mitul Luhar
Keyword(s):  
Body Shape ◽  
Control Volume ◽  
Water Channel ◽  
Morphological Plasticity ◽  
The Body ◽  
Sea Star ◽  
Sea Stars ◽  
Hydrodynamic Loads ◽  
Spherical Dome ◽  
Star Models

AbstractIntertidal sea stars often function in environments with extreme hydrodynamic loads that can compromise their ability to remain attached to surfaces. While behavioral responses such as burrowing into sand or sheltering in rock crevices can help minimize hydrodynamic loads, previous work shows that sea stars also alter body shape in response to flow conditions. This morphological plasticity suggests that sea star body shape may play an important hydrodynamic role. In this study, we measured the fluid forces acting on surface-mounted sea star and spherical dome models in water channel tests. All sea star models created downforce, i.e., the fluid pushed the body towards the surface. In contrast, the spherical dome generated lift. We also used Particle Image Velocimetry (PIV) to measure the midplane flow field around the models. Control volume analyses based on the PIV data show that downforce arises because the sea star bodies serve as ramps that divert fluid away from the surface. These observations are further rationalized using force predictions and flow visualizations from numerical simulations. The discovery of downforce generation could explain why sea stars are shaped as they are: the pentaradial geometry aids attachment to surfaces in the presence of high hydrodynamic loads.

scholarly journals A checklist of gilled mushrooms (Basidiomycota: Agaricomycetes) with diversity analysis in Hollongapar Gibbon Wildlife Sanctuary, Assam, India

2015 ◽  
Vol 7 (15) ◽  
pp. 8272 ◽  
Author(s):  
Girish Gogoi ◽  
Vipin Parkash
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
Abundant Species ◽  
Shannon Diversity Index ◽  
Diversity Analysis ◽  
Wildlife Sanctuary ◽  
Shannon Diversity ◽  
Number Of Species ◽  
Simpson Diversity Index ◽  
Richness Index

<p>Hollongapar Gibbon Wildlife Sanctuary is comprised of five distinct compartments.  A total of 138 species of gilled mushrooms belonging to 48 genera, 23 families, five orders of the class Agaricomycetes, division Basidiomycota, have been collected and analyzed. The order Agaricales was was found with the highest number of species (113), followed by Russulales (14), Polyporales (5), Cantharellales (4) and Boletales (2). The species <em>Coprinellus disseminatus </em>and <em>Megacollybia rodmani</em> have shown the highest (8.26) and the lowest density (0.05), respectively.  A total of 24 species, e.g., <em>Termitomyces albuminosus, Marasmius curreyi, Marasmiellus candidus, Leucocoprinus medioflavus, Mycena leaiana, Hygrocybe miniata, Collybia chrysoropha, Gymnopus confluens</em> were common with frequency percentage of 11.9, whereas <em>Megacollybia rodmani</em> with less frequency percentage (2.4) was found only in few quadrates of the sanctuary.  The highly abundant species were <em>Termitomyces medius</em> (91.7) and <em>Coprinellus disseminatus </em>(86.8), and less abundant species were <em>Psilocybe wayanadensis</em> (1.0) and <em>Lepiota</em> sp. (1.0) in the study site.  The order of the species richness index (<em>R</em>) compartment wise was 2&gt;3&gt;4&gt;5&gt;1. Both the Shannon diversity index and Simpson diversity index of agarics was maximum (1.88, 0.98) in compartment 2, whereas minimum (1.72, 0.95) in compartment 1 and 5, respectively.  Moreover, the compartment 2 was found very much similar with compartment 3 and very less similar with compartment 1.</p><div> </div>

Tanaidacea (Crustacea: Peracarida) from Japan. IV. Shallow-water species from Akajima with notes on the recolonization potential of tanaids

Zootaxa ◽  
2008 ◽  
Vol 1678 (1) ◽  
pp. 1 ◽  
Author(s):  
KIM LARSEN ◽  
MICHITAKA SHIMOMURA
Keyword(s):  
Phylogenetic Analysis ◽  
Shallow Water ◽  
New Genus ◽  
Abundant Species ◽  
Two New Species ◽  
Sandy Habitat ◽  
Nansei Islands ◽  
Shallow Water Species ◽  
Water Species ◽  
Preliminary Phylogenetic Analysis

Two new species of tanaids were collected from colonization traps deployed in a shallow water, sandy habitat off Akajima, Nansei Islands. One new parapseudidaen, Parapseudes arenamans, and one new nototanaidaen genus and species, Paranesotanais longicephalus, are described herein. A preliminary phylogenetic analysis of the closest genera confirms the validity of the new genus and suggests a close affinity between the Leptocheliidae and Nototanaidae. Paranesotanais longicephalus was by far the most abundant species in the habitat. Parapseudes arenamans is faster in colonization of vacant substrate (opportunistic species), while being an inferior competitor to Paranesotanais longicephalus later in succession. A key to Nesotanais and Paranesotanais is provided.

scholarly journals Analysis of fish assemblages in sectors along a salinity gradient based on species, families and functional groups

2013 ◽  
Vol 61 (4) ◽  
pp. 251-264 ◽  
Author(s):  
Ana Carolina dos Passos ◽  
Riguel Feltrin Contente ◽  
Felippe Veneziani Abbatepaulo ◽  
Henry Louis Spach ◽  
Ciro Colodetti Vilar ◽  
...  
Keyword(s):  
Functional Groups ◽  
Fish Assemblages ◽  
Salinity Gradient ◽  
Fish Fauna ◽  
Abundant Species ◽  
Number Of Species ◽  
Salinity Gradients ◽  
Gradient Based ◽  
Subtropical Estuaries ◽  
East West

Here we test the effects of the east-west salinity gradient in the subtropical Paranaguá Bay Estuarine Complex (PEC) on the structure of shallow water fish fauna, determined according to taxonomic (families and species) and functional composition metrics. A total of 152 species were observed. The families with the largest number of species were the Sciaenidae, Carangidae, Haemulidae and Gobiidae. The most abundant species were Atherinella brasiliensis, Harengula clupeola, Anchoa januaria and Anchoa tricolor. Marine stragglers dominated in number of species, followed by marine migrants and estuarine species. Most species were zoobenthivores, followed by piscivores and zooplanktivores. Families and species more frequently associated with estuarine conditions dominated in the mesohaline sector, and those more frequently associated with marine conditions dominated in the euhaline sector. The fish assemblages along the estuarine salinity gradient were found to be better characterized by taxonomic metrics than by functional ones. This is most likely because individuals of all functional groups inhabit all salinity sectors, and thus these metrics are not useful for differentiating assemblages along salinity gradients. Our results differ from those of other studies in tropical and subtropical estuaries, which have emphasized the importance of functional groups in determining fish assemblages along salinity gradients.

Habitat-specific distributions of some fishes in a tropical estuary

1996 ◽  
Vol 47 (6) ◽  
pp. 827 ◽  
Author(s):  
MJ Sheaves
Keyword(s):  
Species Richness ◽  
Abundant Species ◽  
Epinephelus Coioides ◽  
Tropical Estuary ◽  
Habitat Types ◽  
Number Of Species ◽  
Fish Traps ◽  
Tropical Australia ◽  
Sampling Trip ◽  
Probability Of Capture

The species richness of fishes and the distributions of six fish species were compared among four habitat types, snaggy banks, clear banks, mud banks and mid channels, in an estuary in tropical Australia. Both day and night samples were collected in fish traps, on four occasions, three months apart. On each sampling trip the highest number of species was trapped from snaggy habitats, intermediate numbers from clear banks or mud banks, and the fewest species from mid channels. Although more species occurred in night than in day samples, the pattern of difference among habitats was consistent. The probability of capture of the six most abundant species, Acanthopagrus australis, Acanthopagrus berda, Arothron manilensis, Arius argyropleuron, Epinephelus coioides and Lutjanus russelli, was compared among habitat types and between day and night samples. Overall, snag habitats tended to be associated with high probabilities of capture of a number of species, particularly A. berda and L. russelli. At night, mid channels were characterized by high numbers of A. argyropleuron. Clear and mud banks, and day samples from mid channels were associated with low numbers of most species.

A review of the genus Tryphosella (Crustacea: Amphipoda) from Britain and Ireland, with the description of a new species Tryphosella lowryi

2006 ◽  
Vol 86 (5) ◽  
pp. 1067-1081 ◽  
Author(s):  
N.M. Kilgallen ◽  
A.A. Myers ◽  
D. McGrath
Keyword(s):  
New Species ◽  
Shallow Water ◽  
British Isles ◽  
Number Of Species ◽  
Shallow Water Species ◽  
First Time ◽  
A New Species ◽  
Water Species

A review of the shallow-water species of the genus Tryphosella from the British Isles is presented and a new species, Tryphosella lowryi, is described. In addition, Tryphosella minima is recorded from this region for the first time. This brings to five the total number of species of this genus now known from the British Isles. All taxa are fully described and illustrated, and a key to the species is provided.

?Tethyaster albertensis, a Late Cretaceous (Turonian) sea star from the Cardium Formation, Alberta, Canada

1990 ◽  
Vol 64 (6) ◽  
pp. 1045-1049 ◽  
Author(s):  
Russell L. Hall ◽  
Suzan Moore
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Sea Star ◽  
Sea Stars ◽  
Peace River ◽  
The North ◽  
The Family ◽  
Cardium Formation ◽  
Northern Alberta ◽  
Limited Change

Although many of the surviving lineages of sea stars appeared during an early Mesozoic radiation of the class and have undergone limited change since then, they have left a very poor fossil record, particularly in the Mesozoic of North America (Blake, 1981). This record from the Late Cretaceous of Alberta is made more significant by the fact that it is apparently only the second occurrence of a member of the family Astropectinidae in the Cretaceous of North America; Lophidiaster silentiensis was described by McLearn (1944) from the Lower Cretaceous (Albian) Hasler Formation, from a now-submerged locality on the Peace River in northern Alberta. All previously recorded fossil sea stars from the North American Cretaceous are representatives of the family Goniasteridae.

scholarly journals I Macroeteroceri della Riserva Naturale Orientata “Laghetti di Marinello” (Sicilia nord-orientale) (Lepidoptera Heterocera)

2012 ◽  
pp. 31-43
Author(s):  
Marco Infusino ◽  
Concetta Calabrò ◽  
Salvatore Saitta ◽  
Stefano Scalercio
Keyword(s):  
Light Source ◽  
Sono State ◽  
Abundant Species ◽  
Diversity Indices ◽  
Climatic Conditions ◽  
Number Of Species ◽  
Sono Stati ◽  
Natural Reserve ◽  
North Eastern ◽  
First Time

Riassunto - Gli scopi di questa ricerca sono quelli di contribuire alla conoscenza della macrolepidotterofauna della Sicilia nord-orientale e di caratterizzare la comunità presente nella Riserva Naturale Orientata “Laghetti di Marinello”. Sono stati effettuati 23 campionamenti tra dicembre 2007 e dicembre 2008 col metodo della caccia al lume. Sono stati catturati 2.537 individui appartenenti a 160 specie, tra cui Chloroclystis v-ata e Laelia coenosa, segnalate per la prima volta in Sicilia; importanti anche le segnalazioni di Calamodes subscudularia, Mythimna languida e M. joannisi, specie piuttosto rare e localizzate. Le specie più abbondanti sono state: Eilema caniola, Eublemma viridula, Idaea filicata, Dysauxes famula e Idaea seriata, che da sole rappresentano il 42% di tutta la comunità, favorite dalla presenza delle rispettive piante nutrici e dall’elevato adattamento alle condizioni climatiche del sito. Il numero di specie e i valori degli indici di diversità indicano un basso livello di biodiversità ospitata, ma la fenologia, le analisi corologica e autoecologica delle specie, insieme ai confronti effettuati con altre faune, indicano una comunità ben caratterizzata e peculiare, diretta espressione delle condizioni abiotiche e biotiche della Riserva.Abstract - Macroheterocera of the Oriented Natural Reserve “Laghetti di Marinello” (north-eastern Sicily) (Lepidoptera: Heterocera). The aim of this research is to contribute to the knowledge of the fauna of macrolepidoptera of north-eastern Sicily and to describe the community present in the Oriented Natural Reserve “Laghetti di Marinello”. 23 samples were carried out from December 2007 to December 2008 using a white vertical sheet reflecting a light source. 2.537 specimens belonging to 160 species were captured. Chloroclystis v-ata and Laelia coenosa were reported for the first time in Sicily, Calamodes subscudularia, Mythimna languida and M. joannisi, very rare and localized species, were also reported. The most abundant species were: Eilema caniola, Eublemma viridula, Idaea filicata, Dysauxes famula and Idaea seriata, which represent the 42% of the whole community and are favoured by the presence of their feeding plants and by their high adaptability to the climatic conditions of the place. The number of species and the values of the diversity indices show a low level of biodiversity, but phenology, chorological and autoecological analysis of the species, with comparisons made with other faunae, show a well characterized and peculiar community, direct expression of the abiotic and biotic conditions of the Reserve.

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