scholarly journals Reproduction and community structure of fish from winter shrimp bycatch from the Southeast Gulf of California

Author(s):  
Jorge de Jesus Tirado-Ibarra ◽  
Mariany Loya-Rodriguez ◽  
Jose Carlos Morales-Arevalo ◽  
Isabel Rosario Muñoz-Garcia ◽  
Jorge Saul Ramirez-Perez ◽  
...  

Shrimp fishery is one of the most important fisheries of the world. However, the low selectivity from trawl nets leads the capture of a large number of non-target species. Shrimp bycatch include a large number of fish and invertebrate species; of which fish species are the most abundant. The present study aims to determine the community structure as well as the average sizes at first maturity of the fish species from shrimp bycatch caught from industrial fisheries at the southeast of the Gulf of California from Sinaloa to Guerrero, Mexico; from January to March 2015. A total of 37 species of finfish were found; of which five were considered rare. The fish species with the highest Importance Value Index (IVI) were Pseudupeneus grandisquamis, Paralichthys woolmani, Lutjanus peru y Diapterus peruvianus. The average size at first maturity of 12 fish species was determined; nine of which have not been previously reported. Of the analyzed organisms 90% were in juvenile stage; including species with riverine and artisanal fisheries. The present study demonstrates the risk in marine populations of different non-target species due to the low selectivity of shrimp trawls.

2017 ◽  
Author(s):  
Jorge de Jesus Tirado-Ibarra ◽  
Mariany Loya-Rodriguez ◽  
Jose Carlos Morales-Arevalo ◽  
Isabel Rosario Muñoz-Garcia ◽  
Jorge Saul Ramirez-Perez ◽  
...  

Shrimp fishery is one of the most important fisheries of the world. However, the low selectivity from trawl nets leads the capture of a large number of non-target species. Shrimp bycatch include a large number of fish and invertebrate species; of which fish species are the most abundant. The present study aims to determine the community structure as well as the average sizes at first maturity of the fish species from shrimp bycatch caught from industrial fisheries at the southeast of the Gulf of California from Sinaloa to Guerrero, Mexico; from January to March 2015. A total of 37 species of finfish were found; of which five were considered rare. The fish species with the highest Importance Value Index (IVI) were Pseudupeneus grandisquamis, Paralichthys woolmani, Lutjanus peru y Diapterus peruvianus. The average size at first maturity of 12 fish species was determined; nine of which have not been previously reported. Of the analyzed organisms 90% were in juvenile stage; including species with riverine and artisanal fisheries. The present study demonstrates the risk in marine populations of different non-target species due to the low selectivity of shrimp trawls.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4460
Author(s):  
Jorge de Jesus Tirado-Ibarra ◽  
Mariany Loya-Rodriguez ◽  
Jose Carlos Morales-Arevalo ◽  
Isabel Rosario Muñoz-Garcia ◽  
Francisco Martinez-Perez ◽  
...  

The shrimp fishery is one of the most important fisheries in the world, although the low selectivity from trawling nets has led to the capture of a large number of non-target species. Shrimp-bycatch species include a large number of fish and invertebrate species, of which fish species are the most abundant. The present study aims to determine the community structure as well as the average sizes at first maturity of the fish species from shrimp-bycatch caught from industrial fisheries in the Mexican Pacific from Sinaloa to Guerrero, from January to March 2015. The shrimp-bycatch fish diversity value was found to be 2.22. A total of 37 species of finfish were found, of which five were considered rare. The fish species with the highest Importance Value Index (IVI) levels were Pseudupeneus grandisquamis, Paralichthys woolmani, Lutjanus peru and Diapterus peruvianus. The average size at first maturity was calculated for all species. Of the analysed organisms, 90% were in the juvenile stage, including species with riverine and artisanal fisheries. The present study demonstrates the risk within marine populations to different non-target species due to the poor selectivity of shrimp trawls.


2017 ◽  
Vol 70 (1) ◽  
pp. 8035-8043
Author(s):  
Javier Ramírez ◽  
Verónica Hoyos ◽  
Guido Plaza

Studies on weed population dynamics are based on observing and recording changes in weed communities in response to effects of disturbances in crop management. The present study aimed to evaluate weed population dynamics in rice crops in Tolima, Colombia, resulting from post-emergent herbicide applications. Sampling was carried out in 0.1% of the cultivated area, marking out a 1 ha area in each commercial lot. Samples were taken before and after post-emergent applications. Evaluated variables were frequency, density, and cover. The data were analyzed using the Importance Value Index (IVI). Results demonstrated that Echinochloa colona was the most important weed of all of the evaluated zones, before and after post-emergent herbicide applications. Other notable species included Digitaria ciliaris, Cyperus iria and Ischaemum rugosum. Relative frequency variable was the most influential on the importance index of the species. Furthermore, herbicide applications generated changes in the community structure in the evaluated zones and in each evaluation.


2019 ◽  
Vol 17 (1) ◽  
pp. 181
Author(s):  
Sukirman Rahim ◽  
Dewi Wahyuni K Baderan

Hutan mangrove Langge yang terdapat di Kecamatan Anggrek Kabupaten Gorontalo Utara memiliki keunikan dari pola zonasi dan keanekaragaman jenis. Hal ini yang menjadikan hutan mangrove di kawasan tersebut sebagai objek wisata tracking mangrove yang dikenal dengan nama “mangrove in love. Hutan mangrove memiliki berbagai fungsi ekologis yang sangat kompleks yakni sebagai daerah pemijahan  (spawing ground), tempat asuhan (nursery ground), dan tempat mencari makan (feeding ground) biota laut yang beraneka jenis dan memiliki fungsi ekonomis diantaranya buah mangrove dapat diolah menjadi berbagai produk kue dan sumber pangan alternatif pengganti beras. Penelitian ini bertujuan untuk : 1) untuk mengetahui komposisi jenis mangrove asosiasi; 2) untuk mengetahui struktur komunitas dari hutan mangrove Langge; dan 3) nilai Indeks Keanekaragaman. Adapun metode yang digunakan dalam penelitian ini adalah metode jalur berpetak (kombinasi plot dan transek). Jumlah spesies yang ditemukan akan dilihat untuk menjadi dasar penentuan komposisi jenis. Untuk pengkuran struktur komunitas mangrove dengan melakukan perhitungan terhadap Kerapatan Relatif (KR) dan Frekuensi Relatif (FR). Selanjutnya data yang didapatkan ditabulasikan untuk memperoleh nilai Indeks Nilai Penting (INP). Perhitungan keanekaragaman jenis menggunakan rumus (Sannon-wienner). Hasil penelitian menemukan 12 spesies tumbuhan mangrove asosiasi yakni Acanthus spinosus, Chromolaena odorata, Crassocephalum sp, Calotropis gigantean, Ipomea pes-caprae, Ricinus communis Excoecaria agallocha, Scaevola taccada, Spinifex littoreus, Terminalia catappa, Derris trifoliate dan Nypa fruticans. Struktur komunitas menunjukkan Chromolaena odorata memiliki nilai INP sebesar 33,2%, Kerapatan Relatif sebesar 24,91%, dan Frekuensi Relatif sebesar 8,33%.  Spesies dengan nilai INP terendah dimiliki oleh Nypa fruticans yaitu sebesar 9,14%, Kerapatan Relatif sebesar 0,81%, dan Frekuensi Relatif sebesar 8,33%. Nilai Indeks Keanekaragaman (H’) mangrove asosiasi sebesar 2,175 dan termasuk dalam kriteria tingkat keanekaragaman sedang. Data yang diperoleh ini dapat digunakan dalam pengelolaan hutan mangrove di Gorontalo Utara serta dapat menjadi database dalam usaha konservasi mangrove guna mengurangi efek pemanasan global.Langge mangrove forest located in the District of North Gorontalo District Orchid has a uniqueness of zoning patterns and keanekragaman types. This is what makes the mangrove forests in the region as a tourist attraction tracking mangrove known as the "mangrove in love. Mangrove forests have a variety of ecological functions is very complex which is a spawning area (spawing ground), point of care (nursery grounds), and foraging (feeding ground) various types of marine life and has the economic function of which pieces of mangrove can be processed into various products cake and alternative food sources instead of rice. This study aims to: 1) to determine the association of mangrove species composition; 2) to determine the community structure of mangrove forests Langge; and 3) the value of diversity index. The method used in this study is a terraced path method (combination of plots and transects). The composition of the types of views based on the number of species found. For sizing mangrove community structure by calculating the Relative Density (KR) and Relative Frequency (FR). Then the data obtained are tabulated to get the value of Importance Value Index (IVI). Calculation of species diversity using the formula (Sannon-wienner). The study found an association of twelve species of mangrove plants and the relative dominance (DR), then the data obtained are tabulated to get the value of Importance Value Index (IVI). Calculation of species diversity using the formula (Sannon-wienner). The study found an association of eight species of mangrove plants and the relative dominance (DR), then the data obtained are tabulated to get the value of Importance Value Index (IVI). Calculation of species diversity using the formula (Sannon-wienner). The study found an association of twelve species of mangrove plantsnamely Acanthus spinosus, Chromolaena odorata, Crassocephalum sp, Calotropis gigantean, Ipomea pes-caprae, Ricinus communis Excoecaria agallocha, Scaevola taccada, Spinifex littoreus, Terminalia catappa, Derris trifoliate dan Nypa fruticans. Community structure showed Chromolaena odorata has a value of IVI of 33,2%, amounting to 24,91% Relative Density and Relative Frequency of 8,33%. The species with the lowest IVI owned by Nypa fruticans that is equal to 9,14%, 0,81% Relative Density and Relative Frequency of 8,33%. Values Diversity Index (H ') at 2.175 and mangrove associates included in the criteria for a medium level of diversity. The data obtained can be used in the management of mangrove forests in North Gorontalo and can be a database of mangrove conservation efforts to reduce the effects of global warming.


2012 ◽  
Vol 12 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Caroline Cabral Tudesco ◽  
Laís Pinho Fernandes ◽  
Ana Paula Madeira Di Beneditto

This study provides the first data on the population structure of swimming crab Callinectes ornatus Ordway, 1863 bycatch from coastal shrimp fishing in northern Rio de Janeiro State, Brazil (21º 30'-21º 50' S and 41º 05'-41º 07' W). Crabs were collected monthly from April 2006 to March 2007. A total of 5,611 specimens were analyzed, of which 3,951 were males and 1,660 ovigerous and non-ovigerous females. The overall sex ratio (2:1) differ significantly from the expected 1:1 proportion, being the mature males significantly predominant as bycatch in this fishery. The specimens' carapace width and weight varied from 27 to 126 mm (mean: 77.3 ± 12.3 mm) and 1.2 to 128.2 g (mean: 31.0 ± 14.4 g) for males, and 30 to 101 mm (mean: 63.4 ± 9.3 mm) and 1.7 to 66.0 g (mean: 16.4 ± 7.4 g) for ovigerous and non-ovigerous females. Seasonal comparisons did not reveal differences between the number of specimens captured in dry and rainy periods considering both sexes and maturity stages. The size at first maturity was 79 mm for males and 65 mm for females, and the carapace width-weight relationship indicated an alometric pattern for both sexes. The bycatch swimming crabs are locally used as bait, but the capture tendency for a specific sex/age-group can affect this population structure over time.


2021 ◽  
Vol 79 (3) ◽  
pp. 125-135
Author(s):  
Genaro Diarte-Plata ◽  
Ruth Escamilla-Montes ◽  
Salvador Granados-Alcantar ◽  
Antonio Luna-Gonzalez

Abstract The reproductive cycle of the crustacean family Portunidae on the coast of the Pacific is not well known. Therefore, the reproductive cycle and the size at first maturity of brown crab Callinectes bellicosus and its relationship with environmental factors in the El Colorado Lagoon, Ahome, Sinaloa has been determined. A total of 360 females were collected from March 2012 to March 2013. The gonads were fixed in 10% formalin, histological cuts were made by the paraffin inclusion method and the hematoxylin and eosin staining technique. The diameter of oocytes was determined by stage. The size at first maturity was estimated by a logistic model. Females showed gametogenic activity during the entire study period. The maturity period was from March to November 2012, with two spawning peaks, in September 2012 and March 2013. Maturity was inversely influenced by temperature (r = -0.4454, P < 0.05) and no influence by salinity was observed (P > 0.05). The diameter of the oocytes showed significant differences between the development stages of the gonad (P = 0.001). The size at first maturity was 11.57 cm of carapace width for females of C. bellicosus.


Crustaceana ◽  
2020 ◽  
Vol 93 (1) ◽  
pp. 89-109
Author(s):  
Jorge de Jesus Tirado-Ibarra ◽  
Stephanie Jimenez-Gutierrez ◽  
Cristina Acuña-Carvajal ◽  
Isabel Muñoz-Garcia ◽  
Francisco Martinez-Perez ◽  
...  

Abstract In tropical countries, a large number of finfish species and invertebrates are captured as by-catch, including several species of crustaceans, due to the low selectivity of the fishing methods. By-catch presents and optimal opportunity to study populations of crustaceans. Here, the goal was to determine the community structure, specifically through the size structure, as well as the average sizes at first maturity of crustacean species present in the shrimp by-catch caught aboard a fishing vessel operating in the Mexican Pacific, from Sinaloa to Guerrero, Mexico. From the 18 crustaceans found in this study, the crabs Euphylax robustus and Achelous asper were the dominant species, whereas four species were considered casual (i.e., not frequent). Interestingly, more than 40% of the organisms analysed were in the juvenile stage, and 19% were ovigerous females. The results demonstrate the negative impact of the low selectivity of shrimp trawls on the communities of species of Crustacea.


2009 ◽  
Vol 7 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Nelson F. Fontoura ◽  
Aloísio S. Braun ◽  
Paulo Cesar C. Milani

Correct estimates of size at first maturity (L50) are useful for fish stock management and different methods have been proposed. In this study we propose the use of a modified logistic to estimate L50, including a variable asymptote (A). We also test the use of the Gonadossomatic Index (GSI) as a flag to establish the reproductive status of each female fish. The method is demonstrated using GSI data for four Neotropical fish species: Characiformes: Astyanax fasciatus (n = 473) and Oligosarcus robustus (n = 297); Siluriformes: Loricariichthys anus (n = 427) and Trachelyopterus lucenai (n = 195). The results were stable enough to propose this method be used for other fish species with different life histories and with a relatively unconstrained sampling programs. Nevertheless, a wide scale test program is desirable to identify any possible bias in this approach.


2005 ◽  
Vol 71 (1) ◽  
pp. 93-102 ◽  
Author(s):  
Juana López-Martínez ◽  
Carlos Rábago-Quiroz ◽  
Manuel O. Nevárez-Martínez ◽  
Alma Rosa García-Juárez ◽  
Gabriel Rivera-Parra ◽  
...  

2021 ◽  
Vol 22 (11) ◽  
Author(s):  
Uswatun Hasanah ◽  
Hadisunarso Hadisunarso ◽  
Titien Ngatinem Praptosuwiryo

Abstract. Hasanah U, Hadisunarso, Praptosuwiryo TN. 2021. Composition, community structure, and vertical distribution of epiphytic ferns on Cyathea junghuhniana in Gede-Pangrango National Park, Indonesia. Biodiversitas 22: 4968-4976. Epiphytic ferns are a significant component of tropical forests worldwide and contribute significantly to the high species diversity found in tropical regions. Tree ferns are important phorophytes for the establishment and occurrence of epiphytic fern species in tropical forests. The first detailed description of the diversity and abundance of epiphytic ferns on the tree fern Cyathea junghuhniana (Kunze) Copel.  in a natural forest of Indonesia is provided. This study aimed to determine the species composition, richness, abundance, community structure, and vertical distribution of epiphytic ferns growing on the tree fern C.  junghuhniana in the mountain forest of Gede-Pangrango National Park, West Java, Indonesia. The 35 tree fern caudices of at least 3 m height were selected by purposive random sampling. Each tree fern was divided into intervals of 1 meter from ground level to a height of three meters, thus obtaining 105 one-meter samples of the epiphytic fern community on tree fern caudices stratified according to height. The Importance Value Index (IVI) was estimated for each species of epiphyte based on the frequency of occurrence on caudices. The 35 tree fern caudices hosted 760 fern epiphytes belonging to 12 species of 9 genera and 6  families. The highest species richness occurred in Polypodiaceae. The species with the highest Importance Value Index (IVI = 1.24 %) was Nephrolepis davallioides (Sw.) Kunze, with increasing frequency from bottom to top of the caudex.


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