Urban effluents affect the early development stages of Brazilian fish species with implications for their population dynamics

2020 ◽  
Vol 188 ◽  
pp. 109907
Author(s):  
Luiza Santos Barreto ◽  
Angie Thaisa da Costa Souza ◽  
César C. Martins ◽  
Sabrina Borges Lino Araujo ◽  
Ciro Alberto de Oliveira Ribeiro
2020 ◽  
Vol 19 (3A) ◽  
Author(s):  
Wahyulia Cahyanti ◽  
Deni Radona ◽  
Anang Hari Kristanto

Tor fish is a potential local fish. It has social, economic and religious value and contains albumin which is equivalent to snake head fish. As a local fish cultivation potential, an accurate description of the early development stages of this species, will have value for ichthyologists and can facilitate cultivation efforts to increase production. This study aims to understand the embryology of three tor fish species and to determine the condition of larval performance at the beginning of hatching. The division process begins when the cell nucleus is divided into 2 blastomers, then continues to reach 32 cells in the first 10 hours after fertilization. At 10–20 hours after fertilization the eggs enter the morula, blastula and gastrula phases. After 20 hours, the organogenesis stage occurs. Tor douronensis hatched the fastest, more than 100 hours after fertilization (0.70–0.80 cm length, 0.0073 g weight and 8.40±1.83% abnormality). Tor soro over 120 hours (length 0.80–0.90 cm, weight 0.0125 g and abnormality 2.47±0.12%) and Tor tambroides above 140 hours after fertilization (length 1,00–1,09 cm, weight 0,0146 g and abnormality 2.93±0.31%). It can be concluded that there is no difference in the process of embryogenesis of the three species until the gastrula stage. The difference arises in the organogenesis phase, where the Tor douronensis organ develops most rapidly, followed by Tor soro and Tor tambroides.  


Zygote ◽  
2021 ◽  
pp. 1-5
Author(s):  
Nivaldo Ferreira do Nascimento ◽  
Rafaela Manchin Bertolini ◽  
Lucia Soares Lopez ◽  
Laura Satiko Okada Nakaghi ◽  
Paulo Sérgio Monzani ◽  
...  

Summary Triploidization plays an important role in aquaculture and surrogate technologies. In this study, we induced triploidy in the matrinxã fish (Brycon amazonicus) using a heat-shock technique. Embryos at 2 min post fertilization (mpf) were heat shocked at 38°C, 40°C, or 42°C for 2 min. Untreated, intact embryos were used as a control. Survival rates during early development were monitored and ploidy status was confirmed using flow cytometry and nuclear diameter analysis of erythrocytes. The hatching rate reduced with heat-shock treatment, and heat-shock treatments at 42°C resulted in no hatching events. Optimal results were obtained at 40°C with 95% of larvae exhibiting triploidy. Therefore, we report that heat-shock treatments of embryos (2 mpf) at 40°C for 2 min is an effective way to induce triploid individuals in B. amazonicus.


Author(s):  
C.J. Barrett ◽  
M.L. Johnson ◽  
S.L. Hull

The shanny/common blenny (Lipophrys pholis) and long-spined scorpionfish/bullhead (Taurulus bubalis) are commonly encountered, sympatric species within much of Great Britain's rocky intertidal zones. Despite being prey items of the cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) respectively, and both contributors to the diet of the near-threatened European otter (Lutra lutra), little is known on the population dynamics of the temperate specimens of Great Britain. It is further less known of the degrees of sympatricity between the two fish species and to what extent they are able to coexist. The current study examines spatio-temporal distributions and abundances at various resolutions: monthly population dynamics of both species along England's Yorkshire coast and seasonal population dynamics along the Yorkshire coast and around the Isle of Anglesey, Wales. Studies of their abundances, sizes, degrees of rock pool co-occurrence and diel activities are further examined, which indicate coexistence is maintained when interspecific co-occurrence takes place only between specimens of similar sizes, thus demoting size-related dominance hierarchies.


2017 ◽  
Vol 86 (4) ◽  
pp. 888-898 ◽  
Author(s):  
Lauren A. Rogers ◽  
Geir O. Storvik ◽  
Halvor Knutsen ◽  
Esben M. Olsen ◽  
Nils C. Stenseth

2020 ◽  
Vol 43 (2) ◽  
pp. 424-437
Author(s):  
Cristina Andolina ◽  
Piero Franzoi ◽  
Andrew Lloyd Jackson ◽  
Antonio Mazzola ◽  
Salvatrice Vizzini

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
César A. Bonilla-Castillo ◽  
Edwin Agudelo Córdoba ◽  
Guber Gómez ◽  
Fabrice Duponchelle

ABSTRACT The black prochilodus (Prochilodus nigricans) is one of the most landed scaled fish species of the middle and upper parts of the Putumayo River, in the tri-national area between Colombia, Ecuador and Peru. Despite its importance, biological information about this species is too scant to guide fisheries management in this portion of the Colombian Amazon. In this study, 10884 individuals were sampled in the fish markets of Puerto Leguízamo between 2009 and 2017. This sampling was used to document reproductive patterns, but also growth and mortality parameters from length frequency distributions. The size at which all fish were mature was 22 cm Ls, which should be the established as the minimum size of capture to ensure that all fish have had a chance to reproduce before being caught. Growth and mortality parameters indicated a slower growth in the Putumayo than in other Amazonian rivers and a relatively high exploitation rate.


2020 ◽  
Vol 101 (2) ◽  
Author(s):  
Erin E. Easter ◽  
Mia S. Adreani ◽  
Scott L. Hamilton ◽  
Mark A. Steele ◽  
Stephen Pang ◽  
...  

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