scholarly journals Catch rate, length, and sex ratio of Pacific hake (Merluccius productus) in the northern Gulf of California

2020 ◽  
Vol 118 (4) ◽  
pp. 365-379
Author(s):  
Oscar G. Zamora-García ◽  
J. Fernando Márquez-Farías ◽  
Aristóteles Stavrinaky-Suárez ◽  
Carlos Díaz-Avalos ◽  
Noemí I. Zamora-García ◽  
...  
2016 ◽  
Vol 64 (3) ◽  
Author(s):  
Demetrio Angel Rodríguez-Felix ◽  
Miguel Angel Cisneros-Mata ◽  
Eugenio Alberto Aragón-Noriega ◽  
José Alfredo Arreola-Lizárraga

The brown swimming crab (Callinectes bellicosus) is an economically important species in the Gulf of California, and its fishing activity, held in Sonora from 1986, has been affected by a 20-year declining trend in its biomass. With the aim to understand the possible reasons of this species population changes along time, we estimated population growth rate (r) and sex ratio of C. bellicosus, and combined them with three parameters describing its habitat: sea temperature, wetland extension and habitat size in four areas along the coast of Sonora. For this, monthly mean sex ratio was estimated from crabs samples obtained from commercial catches during 1998-2002 and 2012; mean sea surface temperature for the spawning period (May-August) were derived from remote sensors for the same years; while wetland coverages were obtained from published reports, and habitat size was estimated as the fishing surface. For each area, r was estimated using a method developed for limited data situations using commercial landings (t) from 1986-2013. With data from the four areas, simple and multiple linear regression models were developed to ascertain theoretical sensitivities of r to variations in sex ratio and environmental parameters. A total of 24 556 crabs were sampled; males dominated (68.8 %) over females during the study period and in all areas; a cluster analysis identified two groups according to sex ratio: a Northern group with zones 1 and 2, and a Southern group with zones 3 and 4. r values were different in all zones (P<0.001) as was sex ratio (P=0.037); no differences in temperature were identified within the study years (P>0.995). Both the estimated data and sensitivity analyses suggest the existence of a direct and positive dependence of r on the proportion of female crabs and wetland size. We hypothesize that excess fishing of females caused the declining biomass trend of the brown swimming crab in Sonora, and concluded on the convenience of implementing harvest refugia inside coastal wetlands to protect females during the spawning season. 


Chemosphere ◽  
2020 ◽  
Vol 255 ◽  
pp. 126941 ◽  
Author(s):  
L. Gilary Acosta-Lizárraga ◽  
Magdalena E. Bergés-Tiznado ◽  
Carolina Bojórquez-Sánchez ◽  
C. Cristina Osuna-Martínez ◽  
Federico Páez-Osuna

1996 ◽  
Vol 59 (3) ◽  
pp. 312-318 ◽  
Author(s):  
F. L. GARCÍA-CARREÑO ◽  
M. A. NAVARRETE DEL TORO ◽  
M. DÍAZ-LÓPEZ ◽  
M. P. HERNÁNDEZ-CORTÉS ◽  
J. M. EZQUERRA

Seed extracts from indigenous and introduced legumes were prepared and used to search for inhibitors of fish muscle proteinases. Fish flesh extracts were prepared from samples of Merluccius productus (Pacific whiting or merluza) obtained off the Oregon coast and in the Gulf of California, respectively. The proteinase activity in the fish muscle for the Pacific whiting was the highest, followed by parasitized merluza. The lowest proteinase activity was for the nonparasitized merluza. Six out of 12 seed extracts reduced the proteinase activity from the fish flesh by more than 50%. The reduction of enzyme activity was higher for samples of fish flesh extracts from the Gulf of California than for the Oregon samples. Seed extracts also reduced the proteinase activity of commercial serine and cysteine proteinases such as trypsin, chymotrypsin, and papain. This inhibitory capacity was maintained even after heating the seed extracts to 90°C for 15 min. Several seed extracts show promise for use as proteinase inhibitors during production of surimi, the intended commercial product of massive fisheries such as Pacific whiting or merluza.


2008 ◽  
Vol 107 (1) ◽  
pp. 106-111 ◽  
Author(s):  
Miguel Angel Mazorra-Manzano ◽  
Ramón Pacheco-Aguilar ◽  
Juan Carlos Ramirez-Suarez ◽  
Guillermina García-Sánchez

2015 ◽  
Vol 72 (9) ◽  
pp. 2720-2731 ◽  
Author(s):  
Eric M. Iwamoto ◽  
Anna E. Elz ◽  
Francisco J. García-De León ◽  
Claudia A. Silva-Segundo ◽  
Michael J. Ford ◽  
...  

Abstract This study presents the first microsatellite DNA study of population structure of Pacific hake, Merluccius productus (also known as Pacific whiting) within the Salish Sea, which has been identified as a distinct population segment under the US Endangered Species Act and is currently listed as a federal Species of Concern. In contrast, a separate coastal stock component of Pacific hake represents the most abundant commercial groundfish species on the US West Coast. We surveyed variation at 10 microsatellite DNA loci in a total of 655 individuals from three Salish Sea locations (Port Susan (PTS) and Dabob Bay in Washington and south-central Strait of Georgia (SOG) in British Columbia), three coastal locations (two off southern California and one in the Gulf of Alaska), and the Northern Gulf of California (GOC), México. No significant differences were detected among temporal samples from both PTS and SOG locations. Multilocus measures of population subdivision between coastal and Salish Sea populations (all pairwise FST ≥ 0.03) and between PTS and SOG populations (FST ≥ 0.01) suggest a moderate degree of demographic isolation among these spawning populations. No significant genetic differences were found among the three coastal Pacific hake samples; however, Pacific hake from the GOC were significantly differentiated from both coastal (FST &gt; 0.05) and Salish Sea (FST ≥ 0.03) Pacific hake. Correlations between genetic and geographic distance showed that Pacific hake display a very strong isolation by distance signal, both over the whole study area (∼4500 km; r2 = 0.94) and within the Salish Sea (∼280 km; r2 = 0.72). This study suggests that PTS and SOG populations are to some extent demographically isolated from each other.


1996 ◽  
Vol 86 (3) ◽  
pp. 289-296 ◽  
Author(s):  
Marc J.B. Vreysen ◽  
Issa S. Khamis ◽  
André M.V. Van der Vloedt

AbstractMonitoring of Glossina austeni Newstead populations in the forested areas of Unguja island of Zanzibar has since November 1990 routinely been carried out with the sticky panel trap because commonly used tsetse traps (Biconical, Epsilon, F3) have proved to be unsuccessful in catching G. austeni. Initial studies on the catching ability of various types of sticky panels for G. austeni indicated that the monopanel was as efficient in catching flies as the 3-dimensional version and the smaller legpanel. No significant differences in catch rate and sex ratio were observed with monopanels in various colours and colour combinations. Legpanels coloured white on one panel side and blue on the other side caught significantly more flies compared with other colour combinations, but female flies were under-sampled (32%). The type of sticky material applied on the panel influenced significantly the catch rate and female ratio. During long-term trapping with baby blue and white monopanels, females were under-sampled (38–46%) except when polyisobutyleneLMW was used as sticky material. Analysis of the age composition of the sampled G. austeni females revealed that tenerals and nulliparous were well represented (11–24%). More than 20% of the trapped females were older flies, i.e. females with four or more ovulations, but this percentage dropped to 10% when Tanglefoot was used as sticky material.


2012 ◽  
Vol 31 (1) ◽  
pp. 125-134 ◽  
Author(s):  
José Iván Velázquez-Abunader ◽  
Agustín Hernández-Herrera ◽  
Susana Martínez-Aguilar ◽  
Juan Gabriel Díaz-Uribe ◽  
Enrique Morales-Bojórquez

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