Differences in relative abundance and size structure of the sea stars Pisaster ochraceus and Evasterias troschelii among habitat types in Puget Sound, Washington, USA

2012 ◽  
Vol 160 (4) ◽  
pp. 853-865 ◽  
Author(s):  
Tanya L. Rogers ◽  
Joel K. Elliott
Keyword(s):  
Relative Abundance ◽  
Size Structure ◽  
Puget Sound ◽  
Habitat Types ◽  
Sea Stars ◽  
Pisaster Ochraceus

scholarly journals Distribusi dan Kemelimpahan Meiofauna di Hulu Sungai Code Yogyakarta

2012 ◽  
Vol 9 (2) ◽  
pp. 34 ◽  
Author(s):  
Riche - Hariyati
Keyword(s):  
Dissolved Oxygen ◽  
Water Column ◽  
River Water ◽  
Relative Abundance ◽  
Horizontal Distribution ◽  
Water Current ◽  
Habitat Types ◽  
Chemical Parameter ◽  
Physico Chemical

This research is aimed to study distribution and abundance of meiofauna and the quality of physicochemicalcharacteristics of uppersite of code river and up stream river code Yogyakarta province. Samples weretaken using modified Pysto style corer and were located based on habitat types specific river, which are pool, riffle,rapid, left side and right side of water column. Sample taken four times for each zone. The parameter of for waterquality measured were dissolved oxygen. Water current, alkalinity and pHResult from the analysis showed that the abundance of meiofauna at code river the highest at left side zone.Which was 537.806 individu/m3 with relative abundance was 28,09% result from physico chemical parameter ofdissolved oxygenbetween 5,44 ppm – 6,0 ppm, alkalinity 20 ppm – 25 ppm , pH 7,10 – 7,18.and watercurrenntmeasured between 0,03 m/sec – 0,49 m/sec. The abundance of meiofauna at code river was dominated bygroup of Nematodes horizontal distribution of the fauna was the widest for Nematodes ostracoda, Rhizopoda andinsecta. Physico chemicalquality of code river water was relative good for meiofauna habitat and other waterorganisms

Species Composition and Relative Abundance of Large Medusae in Puget Sound, Washington

2010 ◽  
Vol 84 (1) ◽  
pp. 131 ◽  
Author(s):  
Jonathan C. P. Reum ◽  
Mary E. Hunsicker ◽  
Caroline E. Paulsen
Keyword(s):  
Species Composition ◽  
Relative Abundance ◽  
Puget Sound

Corrigendum to: Distribution and relative abundance of forest duikers in Dassioko Sud Forest Reserve (coastal Côte d'Ivoire)

2018 ◽  
Vol 45 (2) ◽  
pp. 194
Author(s):  
K. A. Yao ◽  
E. A. Bitty ◽  
K. B. Kassé ◽  
Y. C. Kouakou ◽  
K. H. Yaokokoré-Beibro ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Habitat Preferences ◽  
Habitat Type ◽  
Distribution Patterns ◽  
Encounter Rate ◽  
Line Transect ◽  
Habitat Types ◽  
Anthropogenic Pressures ◽  
Forest Reserve ◽  
Encounter Rates

Context Duikers play a vital role in maintaining forest ecosystems, as both seed dispersers and prey. In West Africa, duikers are also an important source of food and income; however, it is likely that some species are now being hunted at unsustainable levels. So as to contribute to duiker conservation, we used line-transect data and additional information on dung and track counts to estimate relative abundance and establish distribution patterns of forest duikers in Côte d'Ivoire's Dassioko Sud Forest Reserve (DSFR), a poorly known, remnant coastal rainforest. We also collected basic information on hunting pressure. Methods Forest duiker counts were made twice per month from July 2013 to March 2014 on six line transects of varying lengths (5.6–6.7km) and in different regions of the DSFR, representing different habitat types. The number of sightings per kilometre walked, defined as ‘encounter rate', was used to compute an index of relative abundance. We recorded all evidence of poachers and used these data to generate a poaching index (# poaching signs per kilometre) for different habitat types. Key results The DSFR has lost three of seven total forest duiker species and populations of the four remaining species are declining. Encounter rates were greatest for Philantomba maxwellii (0.46 indices km–1) and accounted for 68% of total encounters. Cephalophus niger, C. dorsalis and C. silvicultor were encountered at similar (0.07 indices km–1) but much lower rates. For all species, mean encounter rates were highest in degraded forest (0.38–0.73 indices km–1), followed by secondary (0.2–0.44 indices km–1) and primary (0.19–0.44 indices km–1) forest. Conclusions Of the four forest duiker species still present in the DSFR, the black, bay and yellow-backed duikers are the most affected by anthropogenic pressures. Duiker abundance in the DSFR varies with habitat type. This variation is apparently influenced by differences in forest structure, poaching pressure and proximity to villages. Implications The study provides baseline data for future managing of ungulate populations in the DSFR. We recommend that a biomonitoring study of duiker populations be initiated immediately to help determine population trends, investigate habitat preferences, and help curb illegal hunting activities in this important forest reserve.

Étude des relations entre les communautés piscicoles et les différents habitats d'une rivière nordique: notion d'habitat optimal

1982 ◽  
Vol 60 (12) ◽  
pp. 3344-3352
Author(s):  
Louise Savard ◽  
Guy Moreau
Keyword(s):  
Relative Abundance ◽  
Condition Factor ◽  
Northern Pike ◽  
Abundant Species ◽  
The Other ◽  
Coregonus Clupeaformis ◽  
Habitat Types ◽  
Linkage Cluster ◽  
Complete Linkage Cluster ◽  
Satellite Species

A complete linkage cluster analysis using the physical characteristics of the sampling sites has revealed the existence of five groups corresponding to five habitat types nonequally distributed in a northern Quebec river. According to the results of discriminant analysis using the relative abundance of the fish species present, these habitats support populations which differ by the relative abundance of species and not by the presence or absence of some particular species. A habitat is first characterized by a species living preferentially in this habitat, then by the other species inhabiting the area in an opportunistic way, and finally by some satellite species which do not seem to have any marked requirements. A habitat is considered as optimal for a species first if this species inhabits this area preferentially to others and secondly if this use is more advantageous for growth or condition factor. This seems to be confirmed for two of the most abundant species, northern pike (Esox lucius) and lake whitefish (Coregonus clupeaformis), both of which have a higher condition factor and a better growth in the part of the river where their optimal habitat is more frequently found.

scholarly journals Quantitative assessment of actin transcript number in eggs, embryos, and tube feet of the sea star Pisaster ochraceus.

1985 ◽  
Vol 5 (11) ◽  
pp. 3001-3008 ◽  
Author(s):  
I Kovesdi ◽  
M J Smith
Keyword(s):  
Relative Abundance ◽  
Untranslated Region ◽  
Quantitative Assessment ◽  
Developmental Stages ◽  
Sea Star ◽  
Dot Blot ◽  
Pisaster Ochraceus ◽  
Hybridization Kinetic ◽  
Muscle Gene ◽  
Tube Feet

Actin coding sequence cDNA probes were used to quantitate the number of transcripts in RNA from eggs, embryos, and tube feet of the sea star Pisaster ochraceus. Transcript concentrations were measured in both total RNA and in poly(A)+ RNA by titration and hybridization kinetic methods. Surprisingly, the actin transcript number in sea star eggs is two orders of magnitude greater than in sea urchin eggs. There are at least 2.9 X 10(5) actin transcripts per sea star egg, 1.2 X 10(5) per 48-h gastrula and 1.9 X 10(5) per 72-h gastrula. The number of actin transcripts per unit mass of extracted tube foot RNA is lower than in developmental stages. The relative abundance and size of actin transcripts was determined by Northern and dot blot analyses using probes containing actin coding DNA or 3'-untranslated-region sequences. The actin transcript in eggs and embryos is 2,300 nucleotides (nt) long and originates from the Cy (cytoplasmic) gene class. In tube feet, the most abundant actin transcript is 2,200 nt long and originates from the M (muscle) gene class. Tube feet also contain, at lower abundance, 2,300-nt transcripts of the Cy gene type expressed in eggs and embryos.

scholarly journals Does habitat structure influence capture probabilities? A study of reptiles in a eucalypt forest

2009 ◽  
Vol 36 (6) ◽  
pp. 509 ◽  
Author(s):  
Michael D. Craig ◽  
Andrew H. Grigg ◽  
Mark J. Garkaklis ◽  
Richard J. Hobbs ◽  
Carl D. Grant ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Vegetation Structure ◽  
Habitat Structure ◽  
Pitfall Traps ◽  
Total Removal ◽  
Habitat Types ◽  
Jarrah Forest ◽  
Future Studies ◽  
Eucalypt Forest ◽  
Structural Variables

Pitfall traps are commonly used to examine differences in reptile communities among habitat types and disturbance regimes that differ in structure. However, capture rates and probabilities may be influenced by habitat structure, which invalidates comparisons of relative abundance among habitat types. To assess whether pitfall traps provide accurate reflections of density and whether habitat structure affects capture probabilities, we trapped at six sites in various jarrah-forest habitat types in south-western Australia, then intensively searched 150-m2 total-removal plots around each pitfall grid to obtain absolute densities of reptiles. Pitfall captures were significantly correlated with numbers on total-removal plots for Hemiergis initialis and Lerista distinguenda, indicating that pitfall traps provided accurate reflections of density for these species. Capture probabilities of H. initialis and L. distinguenda and all reptiles combined showed no significant correlations with any structural variables, indicating that capture probabilities were consistent across sites. We conclude that trapping provided accurate estimates of relative abundance for some species and that capture probabilities were not influenced by vegetation structure. Because many studies use trapping to estimate abundances among habitat types, we encourage researchers to investigate how vegetation structure influences capture probabilities, so that general patterns can be determined; we also suggest improvements for any future studies.

scholarly journals Sex-specific Changes in Walleye Abundance, Size Structure and Harvest Following Implementation of Regulation to Protect Broodstock

2015 ◽  
Vol 6 (2) ◽  
pp. 448-455 ◽  
Author(s):  
Keith D. Koupal ◽  
Jordan D. Katt ◽  
Casey W. Schoenebeck ◽  
Brad E. Eifert
Keyword(s):  
Relative Abundance ◽  
Size Structure ◽  
The State ◽  
Minimum Length ◽  
Sander Vitreus ◽  
Data Sets ◽  
Total Catch ◽  
Before And After ◽  
Existing Data

Abstract The popularity of walleye Sander vitreus fishing has resulted in the development of specialized regulations that are designed to protect these fisheries. In the case of Sherman Reservoir, Sherman County, Nebraska, the walleye population provides a sportfishing opportunity and serves as broodstock for the state. In 2009, for the primary purpose of protecting female broodstock, the regulation changed from a harvest limit of four walleye with 457-mm minimum length to allowing a reduced harvest limit of two walleye within a harvest slot (381–508 mm) and one walleye more than 711 mm. This study examined existing data sets to assess the percentage of spawning walleye protected with each regulation, sex-specific differences in relative abundance and size structure during broodstock collection and angler effort, total catch, and harvest of walleye. The new regulation has increased protection of female walleye by more than 90%, but decreased protection of male walleye by more than 60%. The relative abundance of female walleye caught per net during broodstock collection has more than doubled since the regulation was changed, but the size structure of female walleye collected during broodstock operations was similar. Correspondingly, the relative abundance of male walleye has declined since changing the regulation, but size structure remained similar. Effort and total catch of walleye by anglers were similar before and after the regulation was enacted, but harvest has increased by 130%. This regulation appears to protect female broodstock walleye, but it makes male walleye more vulnerable to angler harvest.

scholarly journals Genetic variation associated with lower susceptibility to sea star wasting syndrome in the keystone species, Pisaster ochraceus

2021 ◽  
Author(s):  
Andrea Burton ◽  
Sarah Gravem ◽  
Felipe Barreto
Keyword(s):  
Genetic Variation ◽  
Keystone Species ◽  
Disease Status ◽  
Sea Star ◽  
Sea Stars ◽  
Protein Coding ◽  
Functional Studies ◽  
Pisaster Ochraceus ◽  
Wasting Syndrome ◽  
Asymptomatic Individuals

The keystone species, Pisaster ochraceus, suffered mass mortalities along the northeast Pacific Ocean from Sea Star Wasting Syndrome (SSWS) outbreaks in 2013-2016. Causation of SSWS is still debated, leading to concerns as to whether outbreaks will continue to impact this species. Considering the apparent link between ocean temperature and SSWS, the future of this species and intertidal communities remains uncertain. We surveyed populations of sea stars along the Oregon coast in 2016, two years after the epidemic began. Cohabitation of asymptomatic and symptomatic individuals allowed us to ask whether lower susceptibility in asymptomatic individuals differed genetically. We performed restriction site-associated DNA sequencing (2bRAD-seq) to genotype thousands of single nucleotide polymorphism (SNP) loci. By comparing allele frequencies between symptomatic and asymptomatic individuals, we detected three loci that may be under selection. A multivariate analysis showed a clear separation between groups based on disease status in two of the three geographic regions, along with several regions across the genome having small statistical contributions to this separation. A draft annotation of protein-coding regions allowed us to identify 120 predicted genes that are linked to these markers and are putatively associated with lower susceptibility. Our results suggest that some variation in disease severity can be attributed to genetic variation. However, differences in phenotype have a highly polygenic nature with no single or few genomic regions having strong predictive effects. The genes associated with these regions may form the basis for functional studies aiming to understand disease progression in infected individuals.

Red Snapper: Ecology and Fisheries in the U.S. Gulf of Mexico

2007 ◽  
Keyword(s):  
Gulf Of Mexico ◽  
Reef Fish ◽  
Relative Abundance ◽  
Fish Assemblages ◽  
Red Snapper ◽  
Lutjanus Campechanus ◽  
Reef Habitat ◽  
Habitat Types ◽  
North Central ◽  
The North

<em>Abstract.</em>—Video estimation of the relative abundance of fishes is a noninvasive method commonly used to assess fish densities. This technique can be used to characterize habitat use patterns either of fish assemblages or of a particular species of interest. The objectives of this study were to quantify relative abundance of red snapper, <em>Lutjanus campechanus</em>, and to characterize with video methodology the associated fish assemblages over different habitat types. Fishes were enumerated over sand, shell, and natural hard bottom reef habitats in the north-central Gulf of Mexico (GOM) off Alabama on quarterly cruises over a two-year period with a baited stationary underwater video camera array. Red snapper showed both significantly higher abundance and larger size over the reef habitat; however, no seasonal effects were observed, indicating temporal abundance patterns were consistent among seasons. Fish assemblages differed among habitats, with significant differences between reef and shell assemblages. Efforts to identify the species that most contributed to these differences indicated that the red snapper accounted for 59% of the overall similarity within the reef fish assemblage and 20% of the total dissimilarity between the shell and reef fish assemblages. This study highlights the utility of applying video techniques to identify the importance of sand, shell, and reef habitat types both to different life stages of red snapper, and to the different fish assemblages occupying distinct habitats in the north-central GOM.

Observations on the reproduction and development of Pisaster ochraceus (Brandt)

1981 ◽  
Vol 59 (9) ◽  
pp. 1700-1707 ◽  
Author(s):  
Alex Fraser ◽  
Johanna Gomez ◽  
E. Brian Hartwick ◽  
Michael J. Smith
Keyword(s):  
Normal Development ◽  
Oocyte Size ◽  
Sea Stars ◽  
Pisaster Ochraceus ◽  
Potential Source ◽  
Molecular Studies ◽  
Laboratory Maintenance

Pisaster ochraceus was investigated as a potential source of embryonic material for molecular studies. Minimal conditions for laboratory maintenance of gravid sea stars and a method for induction of spawning are described. Data on oocyte size, yield, and fertilizability are presented as well as a timetable of normal development to bipinnaria larvae and measures of developmental synchrony.

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