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.

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

scholarly journals Biometric differences in Ucides cordatus (LINNAEUS, 1763) (Crustacea; Brachyura; Ocypodidae) as an indicative of environmental stress

2020 ◽  
Vol 11 (2) ◽  
pp. 228-235
Author(s):  
Carmen Hellen da Silva Rocha ◽  
Thamires Barroso Lima
Keyword(s):  
Body Size ◽  
Urban Development ◽  
Environmental Changes ◽  
Condition Factor ◽  
Mangrove Ecosystem ◽  
Reference Area ◽  
Ucides Cordatus ◽  
Digital Caliper ◽  
Port Expansion ◽  
Northeast Coast

Growing urban development, port expansion, and the deployment of industries along the northeast coast of Brazil are some of the major threats to crustacean fauna that depend directly on the mangrove ecosystem to survive. In response to these environmental changes, the swamp ghost crab (Ucides cordatus) presents biological dysfunctions in body size to invest in mechanisms that regulate homeostasis. The present study aimed to evaluate the size and condition factor of crabs from two distinct mangrove areas, being an impacted area and a reference area. Male crabs were collected through the braking technique, weighed with an analytical balance and the width and length of the carapace were measured with a digital caliper. We used a t test to observe differences between two areas and different periods, and the power function (y = axb) for the ratio between the weight and width of the carapace of each individual was used in order to observe the type of growth. There were significant differences between the weight and length of the individuals between the two sample areas and the growth classified as negative allometric.

Sperm competition and fertilization success in Atlantic cod (Gadus morhua): effect of sire size and condition factor on gamete quality

1999 ◽  
Vol 56 (12) ◽  
pp. 2315-2323 ◽  
Author(s):  
Ana Rakitin ◽  
Moira M Ferguson ◽  
Edward A Trippel
Keyword(s):  
Body Size ◽  
Sperm Competition ◽  
Gadus Morhua ◽  
Condition Factor ◽  
Atlantic Cod ◽  
Sperm Quality ◽  
Fertilization Success ◽  
Male Body ◽  
Single Female ◽  
Male Condition

Sperm competition experiments were conducted to test the null hypothesis that sperm quality is not affected by male body size in Atlantic cod (Gadus morhua). Genetic markers (allozymes) were used to determine the proportion of larvae sired by pairs of males when their sperm was combined with eggs of a single female simultaneously. Significant differences in fertilization success between males were not explained by differences in body size. Fertilization success was positively associated with male condition factor (K) and with spermatozoa density in each male's semen when equal volumes of semen from each male were used. Male K was positively associated with male fertilization success when the volume of semen used from each male was adjusted to add approximately equal numbers of spermatozoa from each male. The relative fertilization success of males varied depending on which female was the egg donor, suggesting that female "choice" at the gamete level may be occurring in cod.

scholarly journals Anisakid and Raphidascaridid parasites in Trachurus trachurus: infection drivers and possible effects on the host’s condition

2021 ◽  
Author(s):  
Fabio Macchioni ◽  
Perla Tedesco ◽  
Vanessa Cocca ◽  
Andrea Massaro ◽  
Paolo Sartor ◽  
...  
Keyword(s):  
Body Size ◽  
Morphological Analysis ◽  
Condition Factor ◽  
Fish Host ◽  
Trachurus Trachurus ◽  
Nematode Larvae ◽  
The Relationship

AbstractThis study investigated the distribution of nematode larvae of Anisakidae and Raphidascarididae (genera Anisakis and Hysterothylacium) in Trachurus trachurus (Linnaeus, 1758) in the Ligurian and central-northern Tyrrhenian Seas. The relationship between the number of parasites and the length and weight parameters of the fish was assessed, and the possible effect of the parasites on the condition factor was evaluated. A total of 190 T. trachurus specimens were collected in July 2019. Parasites were found in 70 individuals. A total of 161 visible larvae were collected in the viscera. Morphological analysis revealed the presence of Anisakis spp. in 55 fish and Hysterothylacium spp. in 15 fish, while 5 fish showed coinfection with both genera. The specimens subjected to PCR (n = 67) showed that 85% of the Anisakis larvae analyzed belonged to the species A. pegreffii, while the remaining 15% belonged to hybrids of A. pegreffii-A. simplex (s.s.). A total of 58% (n = 7) of the Hysterothylacium larvae analyzed belonged to the species H. fabri, while 42% belonged to the species H. aduncum. Our results support the hypothesis that infection with these parasites does not affect the condition of the fish host analyzed, and that body size and depth are major drivers in determining infection levels with Anisakid and Raphidascaridid nematodes.

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