Microplastic ingestion by fish: Body size, condition factor and gut fullness are not related to the amount of plastics consumed

2020 ◽  
Vol 151 ◽  
pp. 110827 ◽  
Author(s):  
Adriana Neeltje de Vries ◽  
Daniel Govoni ◽  
Sigurður Halldór Árnason ◽  
Pernilla Carlsson
Keyword(s):  
Body Size ◽  
Condition Factor ◽  
Size Condition ◽  
Gut Fullness

Individual Differences in Egg Cannibalism in Female Dark Chub (Pisces: Cyprinidae)

Behaviour ◽  
1995 ◽  
Vol 132 (3-4) ◽  
pp. 237-253 ◽  
Author(s):  
Koji Maekawa ◽  
Osamu Katano
Keyword(s):  
Body Size ◽  
Individual Differences ◽  
Home Range ◽  
Laboratory Experiments ◽  
Condition Factor ◽  
Eating Behaviour ◽  
Egg Cannibalism ◽  
Significant Difference ◽  
Size Condition

AbstractNine of 41 identifiable females of dark chub, Zacco temmincki, in a river cannibalized eggs of other females. There was no significant difference in body size, condition factor or the location of home range between cannibals and noncannibals. In laboratory experiments, one male and two females were introduced into an aquarium to observe the behaviour of individual females while a pair spawned. The response of 16 females to spawning was observed and 15 of 16 females exhibited egg cannibalism. The percentages of egg-eating behaviour for individual females varied from 11.1 to 81.8%, and did not change significantly over the course of the experiment. Dark chub were multiple spawners. In a river the number of spawning sequences for cannibals was significantly higher than that for noncannibals. The number of eggs laid by cannibals was estimated to be 1.55 times as many as that by noncannibals.

scholarly journals Exposure to exogenous egg cortisol does not rescue juvenile Chinook salmon body size, condition, or survival from the effects of elevated water temperatures

2020 ◽  
Vol 10 (5) ◽  
pp. 2466-2477 ◽  
Author(s):  
Theresa R. Warriner ◽  
Christina A. D. Semeniuk ◽  
Trevor E. Pitcher ◽  
Oliver P. Love
Keyword(s):  
Body Size ◽  
Chinook Salmon ◽  
Juvenile Chinook Salmon ◽  
Size Condition ◽  
Juvenile Chinook ◽  
Elevated Water

Platypus (Ornithorhynchus anatinus) body size, condition and population structure in Tasmanian river catchments: variability and potential mucormycosis impacts

2011 ◽  
Vol 38 (4) ◽  
pp. 271 ◽  
Author(s):  
Nick Gust ◽  
Josh Griffiths
Keyword(s):  
Population Structure ◽  
Body Size ◽  
Spatial Scales ◽  
Population Level ◽  
Disease Status ◽  
Volume Index ◽  
Adult Males ◽  
Ornithorhynchus Anatinus ◽  
Size Condition ◽  
River Catchments

Context Despite widespread interest in platypus (Ornithorhynchus anatinus) conservation, it is unclear how their fundamental morphometric and demographic characteristics differ over a range of scales. This hampers impact assessments and understanding of platypus ecology. Although the ulcerative fungal disease mucormycosis has infected platypuses in Tasmania for three decades, its population level impacts and conservation significance remain unknown. Aims This study examined morphometric and demographic patterns in Tasmanian platypuses to provide a basis for investigating impacts of mucormycosis or other anthropogenic disturbances. It also sought to identify important spatial scales of natural variability and the magnitude of seasonal variation in platypus body size, condition and population structure. The hypothesis of higher mucormycosis prevalence and mortality in adult males was also investigated. Methods Extensive live-trapping surveys were conducted from January 2008 to July 2009 in 75 streams and 18 river catchments across Tasmania including King Island. The sex, age, body size, tail volume index, health and moult condition of 195 individuals were assessed, and population age and sex structures characterised. Sampling focussed on assessing variability within and between river catchments and compared populations in river catchments with contrasting disease status. Key results Differences in platypus morphometrics within and between catchments and seasonal moulting patterns were detected. Adult males had higher fat stores than adult females, especially during winter. This study also provided the first evidence of population level consequences of disease in platypuses. The demographic group most commonly affected by mucormycosis was confirmed to be adult males. Differences in male age structure among catchments of varying disease status were consistent with the hypothesis of higher adult male mortality rates and turnover in currently affected catchments. Conclusions More than 25 years after mucormycosis was first detected in Tasmanian platypuses, the disease continues to play a low-level, ongoing role in affected populations. Implications The present study provides the first systematic multi-scale spatial investigation of platypus mucormycosis, which contributes to unravelling the epidemiology of the disease and detecting its impacts. By identifying the magnitude and important scales of morphometric and demographic differences in Tasmanian platypuses the study also assists researchers choose comparable demographic groups and spatial scales for meaningful comparisons in future impact studies.

Metal accumulation in Caspian sturgeons with different feeding niches, condition factor, body size and age

2017 ◽  
Vol 132 ◽  
pp. 43-48 ◽  
Author(s):  
Hadi Poorbagher ◽  
Seyed Vali Hosseini ◽  
Seyed Mehdi Hosseini ◽  
Fereidoon Aflaki ◽  
Joe M. Regenstein
Keyword(s):  
Body Size ◽  
Metal Accumulation ◽  
Condition Factor

scholarly journals The combined effects of temperature and aromatase inhibitor on metamorphosis, growth, locomotion, and sex ratio of tiger frog (Hoplobatrachus rugulosus) tadpoles

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8834
Author(s):  
Yun Tang ◽  
Zhi-Qiang Chen ◽  
You-Fu Lin ◽  
Jing-Yi Chen ◽  
Guo-Hua Ding ◽  
...  
Keyword(s):  
Body Size ◽  
Survival Rate ◽  
Sex Ratio ◽  
Aromatase Inhibitor ◽  
Condition Factor ◽  
Sex Ratios ◽  
Control Group ◽  
Treatment Groups ◽  
Effects Of Temperature ◽  
Steroid Hormone Level

Background The tiger frog (Hoplobatrachus rugulosus) is widely raised by many farms in southern region of China as an economically edible frog. The growth, development, and sexual differentiation of amphibians are influenced by temperature and steroid hormone level. However, the problem of hormone residues is caused by the addition of exogenous hormones in frog breeding, it is worth considering whether non-sterol aromatase inhibitors can be used instead of hormones. Methods In our study, H. rugulosus tadpoles were subjected to two water temperatures (29 °C and 34 °C) and three letrozole concentrations in the feed (0, 0.1 and 1 mg/g) to examine the effects of temperature, aromatase inhibitor and their interaction on metamorphosis, locomotion, and sex ratios. A G-test and contingency table were used to analyze the metamorphosis rate of tadpoles and the survival rate of froglets after feeding for 90 days. A G-test was also used to analyze sex ratios in different treatment groups. Results Metamorphosis time and body size (snout–vent length, body mass and condition factor) were significantly different between the two temperature treatments. Metamorphosis time was longer and body size was increased at 29 °C compared to those at 34 °C. Letrozole concentration and the temperature × letrozole interaction did not affect these variables. The jumping distance of froglets following metamorphosis was positively associated with the condition factor; when controlling for condition factor, jumping distance was not affected by temperature, letrozole concentration and their interaction. Temperature and letrozole concentration also did not affect metamorphosis and survival rate. Sex ratio of the control group (0 mg/g letrozole) was 1:1 at 29 °C, but there were more males at 34 °C. The sex ratios of H. rugulosus treated with letrozole at 29 °C and 34 °C were significantly biased toward males, and male ratio increased as letrozole concentration increased. Furthermore, more males were produced at 34 °C than at 29 °C at each letrozole concentration.

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