Habitat characteristics of the Japanese water shrew, Chimarrogale platycephalus

Mammalia ◽  
2019 ◽  
Vol 83 (3) ◽  
pp. 255-259
Author(s):  
Masahiro A. Iwasa
Keyword(s):  
Generalized Linear Model ◽  
Food Resource ◽  
Habitat Characteristics ◽  
Small Fish ◽  
Fish Farms ◽  
Additional Food ◽  
European Water ◽  
Japanese Water ◽  
Objective Variable ◽  
Neomys Fodiens

Abstract To determine the habitat characteristics of the Japanese water shrew, Chimarrogale platycephalus, seven stream parameters were studied along five streams. The shrew occurred along three of those streams. To evaluate the stream parameters related to water shrew occurrence as an objective variable, a generalized linear model analysis of the five streams was performed. The results indicated that current velocity was the most important parameter in shrew occurrence at p<0.001. The present findings are similar to those for the European water shrew, Neomys fodiens. The number of invertebrates as availability of food resources, however, was not a significant parameter influencing shrew occurrence. Along the banks of the two streams inhabited by C. platycephalus, there are artificially managed leisure fishing sites, and small fish farms have released fish regularly into the streams to stock up fishing resources. Such management of leisure fishing may provide the water shrews with fish as an additional food resource and possibly contribute to the occurrence of C. platycephalus.

Patchwork of oil and gas facilities in Saudi waters of the Arabian Gulf has the potential to enhance local fisheries production

2015 ◽  
Vol 72 (8) ◽  
pp. 2398-2408 ◽  
Author(s):  
Lotfi Rabaoui ◽  
Yu-Jia Lin ◽  
Mohammad A. Qurban ◽  
Rommel H. Maneja ◽  
Javier Franco ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Arabian Gulf ◽  
Habitat Characteristics ◽  
Small Fish ◽  
Faunal Assemblages ◽  
Fishery Resources ◽  
Management Measures ◽  
Coastal Embayments ◽  
Oceanographic Variables

Abstract Because of the increasing oil industry development in the Arabian Gulf, hundreds of oil and gas facilities have been installed in both offshore and inshore areas during the last few decades. However, no studies have been conducted till now on the influence of these platforms on the structure and composition of marine faunal assemblages. The present work addresses this issue to propose environmental management measures connected to the utilization of fishery resources. Offshore and inshore surveys were carried out along the Saudi Gulf waters using trawl and beach-seine nets, respectively. Data relative to only fish (offshore) and fish and invertebrates (inshore) were collected concurrently with several factors: density of oil and gas facilities (offshore), distance to the nearest coastal platform (inshore), oceanographic variables, and habitat characteristics. Results of offshore surveys indicated higher fish density—both total and of fishery resources—in locations with a higher number of oil and gas facilities within a 5 km radius, whereas biomass density was not significantly different. Hence, oil and gas facilities seem to serve as nursery areas for small fish. For inshore communities, more species and diversity were found in stations closer to coastal oil and gas facilities. In addition, among the five coastal embayments sampled, those with more oil and gas facilities had more species. The findings of the present work support the hypothesis of a positive net ecological role of oil and gas platforms of the Saudi Arabian Gulf, with the implication that this effect could be extended to improve the sustainability of important fishery resources.

scholarly journals Heavy Metals in Biota in Delaware Bay, NJ: Developing a Food Web Approach to Contaminants

Toxics ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 34
Author(s):  
Joanna Burger ◽  
Nellie Tsipoura ◽  
Larry Niles ◽  
Amanda Dey ◽  
Christian Jeitner ◽  
...  
Keyword(s):  
Food Web ◽  
Striped Bass ◽  
Ecological Integrity ◽  
Food Resource ◽  
Sublethal Effect ◽  
Delaware Bay ◽  
Small Fish ◽  
Pomatomus Saltatrix ◽  
Metal Levels ◽  
Cadmium Lead

Understanding the relationship between heavy metal and selenium levels in biota and their foods is important, but often difficult to determine because animals eat a variety of organisms. Yet such information is critical to managing species populations, ecological integrity, and risk to receptors (including humans) from consumption of certain prey. We examine levels of cadmium, lead, mercury, and selenium in biota from Delaware Bay (New Jersey, USA) to begin construction of a “springtime” food web that focuses on shorebirds. Horseshoe crab (Limulus polyphemus) eggs are one of the key components at the base of the food web, and crab spawning in spring provides a food resource supporting a massive stopover of shorebirds. Fish and other biota also forage on the crab eggs, and a complex food web leads directly to top-level predators such as bluefish (Pomatomus saltatrix) and striped bass (Morone saxatilis), both of which are consumed by egrets, eagles, ospreys (Pandion haliaetus), and humans. Metal levels in tissues were generally similar in algae, invertebrates, and small fish, and these were similar to those in blood of shorebirds (but not feathers). There was a significant direct relationship between the levels of metals in eggs of horseshoe crabs and mean metal levels in the blood of four species of shorebirds. Metal levels in shorebird feathers were higher than those in blood (except for selenium), reflecting sequestration of metals in feathers during their formation. Levels in feathers of laughing gulls (Leucophaeus atricilla) were similar to those in feathers of shorebirds (except for selenium). Selenium bears special mention as levels were significantly higher in the blood of all shorebird species than in other species in the food web, and were similar to levels in their feathers. Levels of metals in bluefish and striped bass were similar or higher than those found in the blood of shorebirds (except for selenium). The mean levels of cadmium, lead, and mercury in the blood and feathers of shorebirds were below any effect levels, but selenium levels in the blood and feathers of shorebirds were higher than the sublethal effect levels for birds. This is a cause for concern, and warrants further examination.

Optimal prey size for stream resident brown trout (Salmo trutta): tests of predictive models

1986 ◽  
Vol 64 (3) ◽  
pp. 704-713 ◽  
Author(s):  
Eileen Bannon ◽  
Neil H. Ringler
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Prey Size ◽  
Food Resource ◽  
Handling Time ◽  
Minimum Size ◽  
Small Fish ◽  
Order Stream ◽  
Mouth Size ◽  
Brown Trout Salmo Trutta

The time required to handle different-sized prey (crickets) was measured in an artificial stream for eight wild brown trout (Salmo trutta L.) in two size classes (mean total lengths, 186 and 214 mm). Handling times (HTs) scaled by mouth size were described by an exponential equation: HT = 1 + 0.84e2.35(ps/ms) (ps, prey size; ms, predator (mouth) size). Cost curves based on handling time/prey weight were used to predict optimal prey lengths of 22 mm for small trout and 24 mm for large trout. A second model based on J. W. J. Wankowski's empirical results predicted slightly smaller optima. Physical constraints provided estimated minimum prey lengths of 2.8 and 3.2 mm for large and small fish, respectively; maximum prey lengths were 89 and 97 mm, respectively. We compared the predicted optimal prey size with the size distribution of invertebrates in drift and brown trout stomachs sampled in a second-order stream from July to September 1982. The most abundant prey sizes in the study stream were near the minimum size that can be effectively handled by brown trout. Prey of the predicted optimum size were rare, but feeding was size selective in spite of a limited food resource. The growth rates of these stream-dwelling brown trout were slower than the brown trout in other streams in this region. This may reflect diets consisting largely of suboptimal-sized prey.

Variation in anti-predator behaviors of white-tailed deer (Odocoileus virginianus) in a multi-predator system

2019 ◽  
Vol 97 (11) ◽  
pp. 1030-1041
Author(s):  
E.R. Olson ◽  
T.R. Van Deelen ◽  
S.J. Ventura
Keyword(s):  
Odocoileus Virginianus ◽  
Interspecific Interactions ◽  
Food Resource ◽  
Risky Behaviors ◽  
Behavioral Observation ◽  
Relative Effect ◽  
Habitat Characteristics ◽  
Intraspecific Interactions ◽  
Intraspecific Interaction ◽  
A Site

Anti-predator responses to perceived predation risk can influence population demography. Understanding the relative effect of predator exposure and intraspecific interactions across a variety of anti-predator behaviors provides important insight into inter- and intra-specific drivers of species-specific behaviors. We merged classical behavioral observation methods with camera trapping techniques to examine anti-predator behaviors of white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) relative to variation in predator exposure and interspecific interactions. We coded 772 behavioral observations from >180 000 images spanning 605 trap-nights. Seasonal differences in behavioral responses to diminishing returns on foraging effort indicated that deer are risk-averse foragers and are more likely to exhibit risky behaviors in the presence of a concentrated food resource when the nutritional value of food resources are high. However, deer tended to spend less time at a site as resources diminished, supporting marginal value theories of habitat use. Intraspecific interaction predicted vigilance and the amount of time spent at a site. Similar to many other species, deer tended to be less vigilant and spend more time at a site as group size increased. Our research suggests that white-tailed deer in Wisconsin make foraging decisions based on factors associated with individual fitness, presence of conspecifics, and habitat characteristics.

scholarly journals BEBERAPAASPEK BIOLOGI IKAN OSKAR (Amphilophus citrinellus) DI WADUK IR. H. DJUANDA, JATILUHUR, JAWA BARAT

2017 ◽  
Vol 3 (1) ◽  
pp. 9
Author(s):  
Sri Endah Purnamaningtyas ◽  
Didik WahjuHendro Tjahjo
Keyword(s):  
Economic Value ◽  
Mesh Size ◽  
Food Habit ◽  
Small Fish ◽  
Fish Feed ◽  
Insect Larvae ◽  
Additional Food ◽  
Gonad Maturity ◽  
Amphilophus Citrinellus ◽  
Territorial Water

Ikan oskar (Amphilophus citrinellus) telah berkembang pesat di Waduk Ir. H. Djuanda, di mana keberadaannya dianggap meresahkan pada kebanyakan nelayan setempat. Ikan ini mempunyai nilai ekonomis yang rendah dan bersifat omnivora-karnivora, diduga perkembangan ikan ini mampu mendesak perkembangan jenis ikan lainnya di perairan tersebut. Tujuan dari penelitian ini adalah untuk mengetahui beberapa aspek biologi ikan oskar, meliputi pola kebiasaan pakan ikan, tingkatkematangan gonad, dan fekunditas yang dilakukan di Waduk Ir. H. Djuanda, Jatiluhur. Penelitian ini dilakukan pada bulan Maret, Juni, Agustus, Oktober, dan Desember 2006. Pengambilan contoh ikan menggunakan gillnet percobaan dengan ukuran mata jaring 1; 1,5; 2; 2,5; 3; 3,5; dan 4 inci. Ikan oskardi waduk Ir. H. Djuanda merupakan ikan omnivora-karnivora yang memanfaatkan tumbuhan dan ikan sebagai pakan utamanya, larva serangga, dan fitoplankton sebagai pakan tambahan dan serangga, detritus dan zooplankton sebagai pakan pelengkap. Dari hasil pengamatan yang dilakukan didapatkan bahwa ikan oskar dapat berkembang dan bertelur sepanjang waktu dan fekunditasnya berkisar antara 1.595-3.567 butir. Oskar (Amphilophus citrinellus) has rapidly expanded in Ir. H. Djuanda Reservoir, where existence of the fish is assumed fretting by local fishermen. This fish has low economic value and the character is omnivore-carnivore, development anticipation of this fish can depress growth of other fish species in the territorial water. This research aims to know some biology aspects of Oskar in Ir. H. Djuanda Reservoir, such as food habit, level of gonad maturity, and fecundity. This study is conducted in March, June, August, October, and December 2006. Gillnet with mesh size of 1; 1.5; 2; 2.5; 3; 3.5; and 4 inch were used for fish sampling. This species is categorised in omnovora-carnivora fish feed mainly on plant and small fish, while insect larvae and phytoplankton as additional food and insect, detritus andzooplankton as complement food. From this study resulted thet oskar could develop and spawn in a long season with fecundity range from 1,595-3,567 grains.

scholarly journals Biological and Ecological Observation of Rasbora sp. for Conservation and Domestication Purpose in Lake Ie Sayang

2021 ◽  
Vol 934 (1) ◽  
pp. 012013
Author(s):  
F Rahmayanti ◽  
N Najmi ◽  
Munandar ◽  
D Islama
Keyword(s):  
Water Quality ◽  
Sex Ratio ◽  
Body Length ◽  
Natural Habitat ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Habitat Characteristics ◽  
Ex Situ ◽  
Small Fish ◽  
Fish Samples

Abstract Lake Ie Sayang provides habitat to several variety of aquatic animals including small fish such as Rasbora sp. However, their existences in nature are increasingly decline due to overfishing and degradation of its natural habitat. The objective of this study was to investigate some habitat characteristics, biological and ecological aspects of bileh fish (Rasbora sp.). Water quality parameters were recorded in situ and fish samples were collected from the water in four stations during April to July 2021. Fish sex ratio and body length-weight were measured ex situ. The data are presented in table and analyzed descriptively. The result revealed that this fish was mainly found at station 1. This station is characterized by the presence of several aquatic plants as feeding ground and fish sanctuary. This fish was easy to find in the mid-water level to water surface and near the land. The water quality parameters revealed that the temperature was in the range 30.2°C to 31.9°C, pH 6.13 to 6.35, DO 3.0 mg/l to 5.25 mg/l, and transparency 47 cm to 58 cm. Fish sex ratio showed that the overall number of females was higher than males with the average range of fish body length-weight were 34.05 mm to 41.33 mm and 1.25 g to 1.58 g respectively.

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