Effects of age, maturity stage, sex and seasonality on the feeding strategies of the diamond stingray (Hypanus dipterurus) in the southern Gulf of California

2020 ◽  
Author(s):  
Diana C. Restrepo-Gómez ◽  
Víctor H. Cruz-Escalona ◽  
Mark S. Peterson ◽  
Paola A. Mejía-Falla ◽  
Andrés F. Navia
Keyword(s):  
Gulf Of California ◽  
Feeding Strategies ◽  
Maturity Stage

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
Gulf Of California ◽  
Average Length ◽  
Gonad Development ◽  
Maturity Stage ◽  
Important Species ◽  
Conservation Ecology ◽  
Gill Net ◽  
Negative Effect ◽  
First Maturity ◽  
Fishing Practices

<em>Abstract</em>.—The chihuil sea catfish <em>Bagre panamensis </em>from the southeastern Gulf of California is an important species that is commercially exploited. Currently, the species is thought to have relatively high abundances. However, studies on biology of this species are scarce; therefore, harvest regulations do not exist for this species in Mexico. The aim of this work was to describe reproductive biology of this species as an initial basis for management of this resource, to assess if the current fishing practices could have an effect on its population, and finally, to begin promoting effective management of this population. Gill-net samples were carried out from October 2008 to October 2009. All fish were dissected; gender and gonad maturity stage were determined macroscopically. Results indicated that the spawning season runs from May to August and generally with synchronic gonad development. Fecundity of the chihuil sea catfish was 36, which is low because this species shows parental care via oral incubation of fry, reducing mortality. Estimated length at first maturity is 350 mm total length (TL). Average length at first catch from the artisanal gill-net fishery is 300 mm TL, indicating that this fishery is harvesting fish that have yet to have had a single reproductive event. A large number of captured fish consisted of males that were incubating fry, thus, likely causing large fry mortality. Current harvest practices may have a negative effect on the chihuil sea catfish population in the Gulf of California. A closed season is proposed for this species from May to August with a minimum harvest length of 400 mm TL.

Morphometry and histology to assess the maturity stage of three endangered devil ray species (Elasmobranchii: Mobulidae) from the Gulf of California

2021 ◽  
Author(s):  
Javier Noe Serrano‐López ◽  
Katherin Soto‐López ◽  
Rosa Isabel Ochoa‐Báez ◽  
John O'Sullivan ◽  
Felipe Galván‐Magaña
Keyword(s):  
Gulf Of California ◽  
Maturity Stage

scholarly journals Influence of sex and maturity state on trace elements content in liver and muscle of the SciaenidaeTotoaba macdonaldi

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11068
Author(s):  
Lia C. Méndez-Rodríguez ◽  
Berenice Hernández-Aguilar ◽  
Juan A. de Anda-Montañez ◽  
Eduardo F. Balart ◽  
Martha J. Román-Rodríguez ◽  
...  
Keyword(s):  
Trace Elements ◽  
Gulf Of California ◽  
Linear Models ◽  
Human Consumption ◽  
Fish Length ◽  
Maturity Stage ◽  
Dietary Reference Intake ◽  
Total Fish ◽  
Totoaba Macdonaldi ◽  
Migratory Movements

BackgroundThe fishTotoaba macdonaldiis endemic to the Upper Gulf of California. Its migratory movements involve sites with high levels of trace elements in the environment that can accumulate in tissues. In this study, lead (Pb), copper (Cu), cadmium (Cd), zinc (Zn) and iron (Fe) concentrations in male and female totoaba liver and muscle were quantified at various sexual maturity stages along the species’ geographic distribution.MethodsGeneralized linear models were used to explore associations between trace element concentrations and season of the year, sex/maturity stage, and total fish length.ResultsNo detectable Pb concentrations were recorded in liver or muscle; Cu, Cd, Zn and Fe contents in totoaba liver and muscle were typical of fish inhabiting areas with no contamination issues and are within international maximum permissible levels for human consumption. Variations in the content of Cd, Cu, Zn and Fe in liver of totoaba seem to be more related to the feeding and reproductive physiology of this species than as result of environmental exposure. Results suggest that consumption of totoaba muscle does not pose a public health risk. Furthermore, depending on the sex/maturity stage of totoaba, this fish’s muscle may provide approximately 70% Cu, 60% Zn and 100% Fe of the recommended dietary reference intake.

Dissolved oxygen and temperature best predict deep-sea fish community structure in the Gulf of California with climate change implications

2020 ◽  
Vol 637 ◽  
pp. 159-180
Author(s):  
ND Gallo ◽  
M Beckwith ◽  
CL Wei ◽  
LA Levin ◽  
L Kuhnz ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Community Composition ◽  
Environmental Conditions ◽  
Deep Sea ◽  
Gulf Of California ◽  
Fish Community ◽  
Demersal Fish ◽  
Fish Community Structure ◽  
Explained Variance

Natural gradient systems can be used to examine the vulnerability of deep-sea communities to climate change. The Gulf of California presents an ideal system for examining relationships between faunal patterns and environmental conditions of deep-sea communities because deep-sea conditions change from warm and oxygen-rich in the north to cold and severely hypoxic in the south. The Monterey Bay Aquarium Research Institute (MBARI) remotely operated vehicle (ROV) ‘Doc Ricketts’ was used to conduct seafloor video transects at depths of ~200-1400 m in the northern, central, and southern Gulf. The community composition, density, and diversity of demersal fish assemblages were compared to environmental conditions. We tested the hypothesis that climate-relevant variables (temperature, oxygen, and primary production) have more explanatory power than static variables (latitude, depth, and benthic substrate) in explaining variation in fish community structure. Temperature best explained variance in density, while oxygen best explained variance in diversity and community composition. Both density and diversity declined with decreasing oxygen, but diversity declined at a higher oxygen threshold (~7 µmol kg-1). Remarkably, high-density fish communities were observed living under suboxic conditions (<5 µmol kg-1). Using an Earth systems global climate model forced under an RCP8.5 scenario, we found that by 2081-2100, the entire Gulf of California seafloor is expected to experience a mean temperature increase of 1.08 ± 1.07°C and modest deoxygenation. The projected changes in temperature and oxygen are expected to be accompanied by reduced diversity and related changes in deep-sea demersal fish communities.

First Leucistic Bottlenose Dolphin (Tursiops truncatus) Sighting Registered in the Gulf of California, Mexico

2019 ◽  
Vol 45 (5) ◽  
pp. 507-512
Author(s):  
Héctor Pérez-Puig ◽  
Gisela Heckel ◽  
Lorayne Meltzer
Keyword(s):  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Gulf Of California

Rehabilitation and Movement of a Blind California Sea Lion from the Southern Gulf of California to the Western Baja California Peninsula, Mexico

2018 ◽  
Vol 44 (3) ◽  
pp. 293-298
Author(s):  
Fernando R. Elorriaga-Verplancken ◽  
Patricia Meneses ◽  
Abraham Cárdenas-Llerenas ◽  
Wayne Phillips ◽  
Abel de la Torre ◽  
...  
Keyword(s):  
Gulf Of California ◽  
Baja California ◽  
Baja California Peninsula ◽  
Sea Lion ◽  
California Sea Lion

Profitability of dairy farming in relation to the type of feeding system

2011 ◽  
Vol 28 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Jan Frelich ◽  
Martin Šlachta ◽  
František Střeleček ◽  
Jana Lososová
Keyword(s):  
Arable Land ◽  
Principal Component ◽  
Dairy Farming ◽  
Plant Production ◽  
Feeding Strategies ◽  
Feeding System ◽  
Financial Health ◽  
Profit Rate ◽  
Permanent Housing ◽  
Cow Performance

Profitability of dairy farming in relation to the type of feeding systemWe investigated the profitability of dairy farms in relation to the type of feeding system (seasonal pasture vs. permanent housing). An economic analysis was carried out of data on the structure and financial health of 50 farms in 2007 using questionnaires filled in by the farmers. The Principal Component Analysis (PCA) was applied to reveal causal relationships between a number of characteristics of the farms. The two axis of PCA explained 40.48% and 16.13% of the variability among the selected farm characteristics. Profitability related more to the number of subsidies, the area of arable land, the number of livestock and to the milk and plant production than to the area of meadows and pastures. Although a better cow performance was achieved on farms with confined herds, the profit per agricultural area and profit rate did not differ significantly between the two feeding strategies (P>0.05). The profit was 3,259 and 3,655 CZK/ha on average and the profit rate 7.9% and 5.6% on average on farms with pastured herds and on farms with confined herds, respectively. A lowering of input costs and a more effective utilisation of grasslands may further enhance profitability.

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