Habitat associations and impacts on a juvenile fish host by a temperate gnathiid isopod

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

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Ellipsomyxa ariusi sp. nov. (Myxosporea: Ceratomyxidae), a new myxosporean infecting the gallbladder of threadfin sea catfish Arius arius in India

Diseases of Aquatic Organisms ◽

10.3354/dao03529 ◽

2020 ◽

Vol 142 ◽

pp. 83-97

Author(s):

A Chandran ◽

PU Zacharia ◽

TV Sathianandan ◽

NK Sanil

Keyword(s):

Phylogenetic Analyses ◽

Type Specimen ◽

Ssu Rdna ◽

Fish Host ◽

Present Species ◽

Epithelial Layer ◽

Histopathological Changes ◽

Mucus Production ◽

High Bootstrap ◽

A New Species

The present study describes a new species of myxosporean, Ellipsomyxa ariusi sp. nov., infecting the gallbladder of the threadfin sea catfish Arius arius (Hamilton, 1822). E. ariusi sp. nov. is characterized by bivalvular, ellipsoid or elongate-oval myxospores with smooth spore valves and a straight suture, arranged at an angle to the longitudinal spore axis. Mature myxospores measured 10.1 ± 0.8 µm in length, 6.8 ± 0.5 µm in width and 7.7 ± 0.7 µm in thickness. Polar capsules are equal in size and oval to pyriform in shape. They are positioned at an angle to the longitudinal myxospore axis and open in opposite directions. Polar capsules measured 2.8 ± 0.3 µm in length and 2.5 ± 0.4 µm in width; polar filaments formed 4-5 coils, and extended to 32.2 ± 2.1 µm in length. Monosporic and disporic plasmodial stages attached to the wall of gallbladder. Molecular analysis of the type specimen generated a 1703 bp partial SSU rDNA sequence (MN892546), which was identical to the isolates from 3 other locations. In phylogenetic analyses, genus Ellipsomyxa appeared monophyletic and E. ariusi sp. nov. occupied an independent position in maximum likelihood and Bayesian inference trees with high bootstrap values. The overall prevalence of infection was 54.8% and multiway ANOVA revealed that it varied significantly with location, year, season, sex and size of the fish host. Histopathological changes associated with E. ariusi sp. nov. infection included swelling, vacuolation and detachment of epithelial layer, reduced mucus production and altered consistency and colour of bile. Based on the morphologic, morphometric and molecular differences with known species of Ellipsomyxa, and considering differences in host and geographic locations, the present species is treated as new and the name Ellipsomyxa ariusi sp. nov. is proposed.

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Acute Toxicity Testing with Juvenile White Sturgeon (Acipenser transmontanus)

Water Quality Research Journal ◽

10.2166/wqrj.1998.006 ◽

1998 ◽

Vol 33 (1) ◽

pp. 95-110 ◽

Cited By ~ 8

Author(s):

W.R. Bennett ◽

A.P. Farrell

Keyword(s):

Acute Toxicity ◽

Swimming Performance ◽

Juvenile Fish ◽

Toxicity Testing ◽

White Sturgeon ◽

Acipenser Transmontanus ◽

Toxicity Tests ◽

Fraser River ◽

Acute Toxicity Tests ◽

Acute Toxicity Testing

Abstract The primary goal of this study was to investigate the possibility of using early life stages of white sturgeon (Acipenser transmontanus) (eggs, larvae and fry) as a species relevant to the Fraser River, B.C., for the acute and sublethal toxico-logical testing of forest industry effluents. Here we report the first successful acute toxicity tests for 8-day-old larvae and 42-day-old fry exposed to several chemicals known to be released into the Fraser River (i.e., 6 monochlorovanillin [6 MVAN], 4,5 dichloroguaiacol [4,5 DCG], 4,5 dichlorocatechol [4,5 DCAT], pentachlorophenol [PCP], and didecyldimethylammonium chloride [DDAC]). In most cases, white sturgeon fry were at the lower end of the range for acute toxicity values for chlorinated phenolic compounds, when compared with other juvenile fish species, and they were extremely sensitive to DDAC. The larval stage was usually more sensitive than the fry stage. Acute toxicity tests with fertilized eggs were unsuccessful. A postexposure growth study was inconclusive because neither control nor toxicant-exposed larvae and fry withstood the additional handling used for measuring body mass. At 62-days-old, fry were more tolerant of handling. This allowed measurement of their swimming performance. Although we have concerns about the reliability of using larvae for acute toxicity testing at this time, 60-day-old white sturgeon fry would appear to be both a sensitive and relevant species for assessing environmental impacts relevant to the Fraser River.

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Modeling spatial distribution of the unionid mussels and the core-satellite hypothesis

Water Science & Technology ◽

10.2166/wst.1998.0279 ◽

1998 ◽

Vol 38 (7) ◽

pp. 73-79 ◽

Cited By ~ 6

Author(s):

Hooi-Ling Lee ◽

Donald DeAngelis ◽

Hock-Lye Koh

Keyword(s):

Spatial Distribution ◽

Life Cycle ◽

Success Rate ◽

Distribution Patterns ◽

Fish Host ◽

Limited Movement ◽

Unionid Mussels ◽

Species Characteristics ◽

Major Factors ◽

Fish Hosts

This paper discusses the spatial distribution patterns of the various species of the Unionid mussels as functions of their respective life-cycle characteristics. Computer simulations identify two life-cycle characteristics as major factors governing the abundance of a species, namely the movement range of their fish hosts and the success rate of the parasitic larval glochidia in finding fish hosts. Core mussels species have fish hosts with large movement range to disperse the parasitic larval glochidia to achieve high levels of abundance. Species associated with fish host of limited movement range require high success rate of finding fish host to achieve at least an intermediate level of abundance. Species with low success rate of finding fish hosts coupled with fish hosts having limited movement range exhibit satellite species characteristics, namely rare in numbers and sparse in distributions.

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Identifying priority core habitats and corridors for effective conservation of brown bears in Iran

Scientific Reports ◽

10.1038/s41598-020-79970-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

A. Mohammadi ◽

K. Almasieh ◽

D. Nayeri ◽

F. Ataei ◽

A. Khani ◽

...

Keyword(s):

Protected Areas ◽

Brown Bear ◽

Population Connectivity ◽

Habitat Associations ◽

Area Network ◽

Zagros Mountains ◽

Range Limit ◽

Brown Bears ◽

Core Areas ◽

Effective Conservation

AbstractIran lies at the southernmost range limit of brown bears globally. Therefore, understanding the habitat associations and patterns of population connectivity for brown bears in Iran is relevant for the species’ conservation. We applied species distribution modeling to predict habitat suitability and connectivity modeling to identify population core areas and corridors. Our results showed that forest density, topographical roughness, NDVI and human footprint were the most influential variables in predicting brown bear distribution. The most crucial core areas and corridor networks for brown bear are concentrated in the Alborz and Zagros Mountains. These two core areas were predicted to be fragmented into a total of fifteen isolated patches if dispersal of brown bear across the landscape is limited to 50,000 cost units, and aggregates into two isolated habitat patches if the species is capable of dispersing 400,000 cost units. We found low overlap between corridors, and core habitats with protected areas, suggesting that the existing protected area network may not be adequate for the conservation of brown bear in Iran. Our results suggest that effective conservation of brown bears in Iran requires protection of both core habitats and the corridors between them, especially outside Iran’s network of protected areas.

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Activation of the peptidergic neurosecretory system in Diphyllobothrium dendriticum (Cestoda: Pseudophyllidea)

Parasitology ◽

10.1017/s0031182000085243 ◽

1981 ◽

Vol 83 (2) ◽

pp. 243-247 ◽

Cited By ~ 24

Author(s):

Margaretha K. S. Gustafsson ◽

Marianne C. Wikgren

Keyword(s):

Neurosecretory Cells ◽

Final Host ◽

Fish Host ◽

Neurosecretory System ◽

Weak Reaction ◽

Diphyllobothrium Dendriticum ◽

Large Numbers ◽

Short Times

SUMMARYThe activation of the peptidergic neurosecretory system in Diphyllobothrium dendriticum was studied following cultivation of plerocercoids for short times in vitro and in vivo. In the plerocercoid the neurosecretory cells gave a very weak reaction with paraldehyde fuchsin (PAF). After cultivation for 1 h large numbers of neurosecretory cells filled with PAF-positive granules were evident. The significance of the activation of the neurosecretory system during the transfer of the worm from the cold-blooded fish host to the warm-blooded final host is discussed.

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Anurans in a Subarctic Tundra Landscape Near Cape Churchill, Manitoba

The Canadian Field-Naturalist ◽

10.22621/cfn.v122i2.571 ◽

2008 ◽

Vol 122 (2) ◽

pp. 129 ◽

Cited By ~ 1

Author(s):

Matthew E. Reiter ◽

Clint W. Boal ◽

David E. Andersen

Keyword(s):

Boreal Forest ◽

Forest Edge ◽

Habitat Associations ◽

Probability Of Detection ◽

Spatial And Temporal Variation ◽

Wood Frogs ◽

Lithobates Sylvaticus ◽

Landscape Types ◽

Species Specific ◽

Monitoring Protocols

Distribution, abundance, and habitat relationships of anurans inhabiting subarctic regions are poorly understood, and anuran monitoring protocols developed for temperate regions may not be applicable across large roadless areas of northern landscapes. In addition, arctic and subarctic regions of North America are predicted to experience changes in climate and, in some areas, are experiencing habitat alteration due to high rates of herbivory by breeding and migrating waterfowl. To better understand subarctic anuran abundance, distribution, and habitat associations, we conducted anuran calling surveys in the Cape Churchill region of Wapusk National Park, Manitoba, Canada, in 2004 and 2005. We conducted surveys along ~1-km transects distributed across three landscape types (coastal tundra, interior sedge meadow–tundra, and boreal forest–tundra interface) to estimate densities and probabilities of detection of Boreal Chorus Frogs (Pseudacris maculata) and Wood Frogs (Lithobates sylvaticus). We detected a Wood Frog or Boreal Chorus Frog on 22 (87%) of 26 transects surveyed, but probability of detection varied between years and species and among landscape types. Estimated densities of both species increased from the coastal zone inland toward the boreal forest edge. Our results suggest anurans occur across all three landscape types in our study area, but that species-specific spatial patterns exist in their abundances. Considerations for both spatial and temporal variation in abundance and detection probability need to be incorporated into surveys and monitoring programs for subarctic anurans.

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Juvenile fish assemblages in the Jinju Bay region, Korea

Fisheries and Aquatic Sciences ◽

10.1186/s41240-020-00175-6 ◽

2020 ◽

Vol 23 (1) ◽

Author(s):

Se Hun Myoung ◽

Seok Nam Kwak ◽

Jin-Koo Kim ◽

Won-Chan Lee ◽

Jeong Bae Kim ◽

...

Keyword(s):

Dominant Species ◽

Fish Assemblages ◽

Juvenile Fish ◽

Young Fish ◽

Monthly Basis ◽

Southern Korea ◽

Pleuronichthys Cornutus ◽

Pennahia Argentata ◽

Hemitripterus Villosus ◽

Number Of Individuals

AbstractAssemblages of juvenile fish and associated abiotic parameters were investigated inside and outside Jinju Bay in southern Korea, on a monthly basis from December 2014 to November 2015. Fluctuations in water temperature and salinity were larger inside than outside the bay. In total, 534,657 individuals per square kilometre from 81 fish species and 47 families were collected during the study period. The most dominant species was Nuchequula nuchalis both inside (25.6%) and outside (26.9%) the bay. The next dominant species were Thryssa kammalensis (17.9%) and Zoarces gillii (16.0%) inside the bay and Liparis tanakae (16.9%) and T. kammalensis (9.0%) outside the bay. Forty species (33% of total number of individuals) of young fish were recorded inside the bay and 47 species (52%) outside the bay. Therefore, it appears that a diversity of fish use nursery grounds inside and outside Jinju Bay. In particular, the following six species appeared: Z. gillii, Pleuronichthys cornutus, L. tanakae, Hemitripterus villosus, Pennahia argentata, and Xenocephalus elongates. Due to assemblage differences for fishes within Jinju Bay and outside the bay, management of both areas is required to maintain current diversity of species in the region.

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