scholarly journals Biological studies and assessment of the exploitation status of the green tiger shrimp Penaeus semisulcatus from Jizan Area, Red Sea

2017 ◽  
Vol 26 (2) ◽  
pp. 23-34
Author(s):  
Lafi S Alsolami and Hassan A Jastania Lafi S Alsolami and Hassan A Jastania

The present study was undertaken to investigate some biological aspects of the green tiger shrimp Penaeus semisulcatus in order to provide the biological information required for its proper management of the fishery in Jizan area, Red Sea. Growth parameters were calculated as (L∞ = 94.40; K = 0.81; to = -0.2); maximum age tmax = 3.7037 years; growth performance indices (ØL = 3.86; Øwt = 1.36). Carapace length at which P. semisulcatus females attained 50% of maturity was 38 mm. The annual mortality coefficients were (Z = 3.124 year-1; M = 1.163 year-1 & F = 1.961 year-1). Carapace length and age at first capture were 35.73 mm and 0.387 year, while carapace length and age at recruitment were 28.52 mm and 0.24 year, respectively. The length at first sexual maturity was found to be 38 mm, while the carapace length at first capture L50 was estimated as 35.73 mm .This indicates that there is a poor opportunity for the recruits of P. semisulcatus in Jizan area to spawn before fishing which is considered an important factor that would lead to overexploitation the stock. The estimated exploitation ratio (0.628) was higher than Emax (0.581) which indicates that, the fisheries status of this species under study is in overexploited.

Author(s):  
Dalilla da Silva Salvati ◽  
Júlia Fernandes Perroca ◽  
Sabrina Morilhas Simões ◽  
Antonio Leão Castilho ◽  
Rogerio Caetano da Costa

AbstractThe study characterized the structure of juveniles and sub-adults of Farfantepenaeus brasiliensis and F. paulensis in the Cananéia-Iguape estuarine lagoon system and its adjacent coastal area by evaluating the period of juvenile recruitment, sex ratio, growth, longevity, natural mortality, and development time until the late juvenile phase. Samples were collected from July 2012 to June 2014. Shrimps were identified by species and sex, and measured (carapace length – CL mm); 889 individuals of F. brasiliensis and 848 of F. paulensis were analysed. Females were more abundant than males for both species. The growth parameters of F. brasiliensis were: CL∞ = 45.5 mm, k = 1.8 year−1 for males and CL∞ = 55.2 mm, k = 1.6 year−1 for females; longevity of 2.52 years (males) and 2.88 years (females); and natural mortality of 1.71 (males) and 1.55 (females). For F. paulensis, the following values were observed: CL∞ = 40.7 mm, k = 2.3 year−1 for males and CL∞ = 56.5 mm, k = 1.9 year−1 for females; longevity of 2.04 years (males) and 2.37 years (females); and natural mortality of 2.39 (males) and 2.05 (females). The juvenile recruitment of both species peaked in January 2014. The development time until late juvenile phase was ~7 months (F. brasiliensis) and ~5 months (F. paulensis). Even though the highest abundance of juveniles did not occur in the closed season, fishing is forbidden in the estuarine area and the migration towards the adult population occurred close to or even during the closed season.


Author(s):  
Najeeb M. A. Rasul ◽  
Ian C. F. Stewart ◽  
Peter Vine ◽  
Zohair A. Nawab
Keyword(s):  
Red Sea ◽  

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1936
Author(s):  
Abdulqader M. Almars ◽  
Majed Alwateer ◽  
Mohammed Qaraad ◽  
Souad Amjad ◽  
Hanaa Fathi ◽  
...  

The growth of abnormal cells in the brain causes human brain tumors. Identifying the type of tumor is crucial for the prognosis and treatment of the patient. Data from cancer microarrays typically include fewer samples with many gene expression levels as features, reflecting the curse of dimensionality and making classifying data from microarrays challenging. In most of the examined studies, cancer classification (Malignant and benign) accuracy was examined without disclosing biological information related to the classification process. A new approach was proposed to bridge the gap between cancer classification and the interpretation of the biological studies of the genes implicated in cancer. This study aims to develop a new hybrid model for cancer classification (by using feature selection mRMRe as a key step to improve the performance of classification methods and a distributed hyperparameter optimization for gradient boosting ensemble methods). To evaluate the proposed method, NB, RF, and SVM classifiers have been chosen. In terms of the AUC, sensitivity, and specificity, the optimized CatBoost classifier performed better than the optimized XGBoost in cross-validation 5, 6, 8, and 10. With an accuracy of 0.91±0.12, the optimized CatBoost classifier is more accurate than the CatBoost classifier without optimization, which is 0.81± 0.24. By using hybrid algorithms, SVM, RF, and NB automatically become more accurate. Furthermore, in terms of accuracy, SVM and RF (0.97±0.08) achieve equivalent and higher classification accuracy than NB (0.91±0.12). The findings of relevant biomedical studies confirm the findings of the selected genes.


Author(s):  
Rouli Verawati Gurning ◽  
Susiana Susiana ◽  
Ani Suryanti

Research on the growth and exploitation status of indian catfish (Plotosus canius) is important in supporting the management of fish resources in the waters of Tanjungpinang City, Riau Islands. The study aims to determine the pattern of growth, growth parameters, and the status of indian catfish exploitation in the waters of Tanjungpinang City, Riau Islands Province. The study was conducted with a purposive sampling method of 3 stations with a total sample of 529 individual fish crosses. Analysis of growth and exploitation status data using FISAT II software and regression analysis using Excel 2017. This study resulted in a pattern of long relations and the weight of fish as a female and males both are negative allometric (faster increase in length than weight increase). The highest rate of exploitation of indian catfish is obtained from the data of 0.73 per year. This exploit value exceeds the optimum exploitation value of 0.5.


2017 ◽  
Vol 9 (1) ◽  
pp. 11
Author(s):  
Tirtadanu Tirtadanu ◽  
Suprapto Suprapto ◽  
Ali Suman

Udang jinga (Metapenaeus affinis H. Milne Edwards, 1837) merupakan salah satu jenis udang ekonomis penting yang diusahakan di perairan Kotabaru dan saat ini produksinya cenderung mengalami penurunan. Salah satu data dan informasi yang diperlukan dalam mengkaji tingkat pemanfaatan dan dasar pengelolaannya adalah aspek biologi dan parameter populasi. Penelitian ini bertujuan mengkaji aspek biologi dan parameter populasi udang jinga sebagai bahan kebijakan pengelolaan perikanan udang di perairan Kotabaru, Kalimantan Selatan. Penelitian dilakukan pada bulan Januari – November 2016 di perairan Kotabaru. Parameter pertumbuhan diestimasi berdasarkan pergeseran modus struktur ukuran panjang dengan metode ELEFAN I. Hasil penelitian menunjukkan rata-rata ukuran udang jinga (M. affinis) betina yang tertangkap adalah 23,6 ± 3,45 mmCL dengan modus ukuran 24 mmCL dan rata-rata ukuran udang jantan adalah 20,7 ± 2,9 mm dengan modus ukuran 18 mmCL. Nisbah kelamin udang jinga jantan dan betina adalah 1 : 2,5. Musim pemijahan udang jinga diduga berlangsung sepanjang tahun dan puncak pada bulan Maret. Ukuran rata-rata pertama kali tertangkap (Lc) udang lebih kecil dari ukuran rata-rata pertama kali matang gonad (Lm) (21,7 < 28,5 mm CL) sehingga sebagian besar udang tertangkap berukuran kecil dan belum memijah. Persamaan pertumbuhan udang jinga jantan  CL(t)=35,95(1-e-2.02(t+0,31) dan udang jinga betina CL(t)= 38,3(1-e-1,92(t+0,29)). Tingkat pemanfaatan udang (E) menunjukkan lebih tangkap (overfishing) yakni 0,70/tahun pada jantan dan 0,73/tahun pada betina. Dengan demikian disarankan untuk melakukan pengurangan upaya penangkapan sebesar 40% dan penutupan musim penangkapan di bulan Maret.The jinga shrimp (Metapenaeus affinis H. Milne Edwards, 1837) was one of important commodity that was exploited in Kotabaru Waters, yet the production tend to be declined recently. The data and information on biological aspects and population parameters are needed to investigate the exploitation level and the basis of management measures. This research aims to investigate the biological aspects and population parameters of jinga shrimp Kotabaru waters, South of Kalimantan. This research was conducted on January – November 2016. The growth parameters were estimated as movement of length frequency mode by ELEFAN I method. The results showed that the mean size of female jinga shrimp (M. affinis) was 23,6 ± 3,45 mm CL and the mode was 24 mmCL. While, the mean size of male jinga shrimp was 20,7 ± 2.9 mm CL and the mode was 18 mmCL. The sex ratio of male and female shrimp was 1 : 2,5 . Spawning season of jinga shrimp was estimated throughout the year and the peak was in March. The length at first captured (Lc) was shorter than length at first matured (Lm) (21,7 < 28,5 mm CL). That means most of the catches was immature. The growth function of male and female jinga shrimp were and, CL(t)=35,95(1-e-2.02(t+0,31) respectively and CL(t)= 38,3(1-e-1,92(t+0,29)). The exploitation rate (E) of male and female shrimp fishing were  0,70/year 0,73/year, respectively. The reduction of fishing effort needed by 40% of the actual combined with the temporal fishing closure March.


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