Analisis Akustik Target Strength Penyu Hijau (Chelonia Mydas) Melalui Pengukuran Secara Terkontrol Pada Frekuensi 200 kHz

2021 ◽  
Vol 3 (2) ◽  
pp. 94-108
Author(s):  
Teddy Julyansyah ◽  
Deddy Bakhtiar ◽  
Ari Anggoro

ABSTRACT Turtles are reptiles that live in the sea and are able to migrate over long distances along the Indian Ocean, Pacific Ocean and Southeast Asia. Currently the number of turtle populations in nature has greatly decreased. This population decline is caused by natural factors and human activities that endanger the population directly or indirectly. At this time the tagging set technique (ID tag code) is a method that is often used to detect the presence of turtles by attaching tags to female turtles who are landing to lay eggs on the beach or while in captivity or the discovery of the mother turtle by fishermen. One other method that can be used to detect the presence of turtles is to use the acoustic method. The purpose of this study was to analyze the characteristics of the acoustic backscattering energy of the green turtle (Chelonia mydes) and to analyze the relationship between target strength and total body length of the green turtle (Chelonia mydas). This research was conducted in the Tapak Paderi waters pond, Bengkulu City, in August-October 2020. The average target strength (TS) value for green turtles was -48.07 dB. Based on the regression equation, the value of determination (R2) obtained is 0.78. Where this value shows that the total length of the green turtle has an effect of 78% on the average target strength (TS) value, while for 22% it is caused by other factors such as body shape, environmental factors and other factors. Based on the ANOVA test, it can be concluded that there is a relationship between the total length and the value of the target strength (TS) on the green turtle or the value of the total length has an influence on the value of the target strength (TS) on the green turtle.  

Fishes ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 39
Author(s):  
Juan R. Esquivel-Muelbert ◽  
Luisa Fontoura ◽  
Éverton Zardo ◽  
Danilo P. Streit Jr. ◽  
Adriane Esquivel-Muelbert ◽  
...  

The reintroduction of threatened fish species in areas where wild populations have been depleted due to anthropogenic impacts is an increasingly popular conservation tool and mitigation policy. Despite the importance of fish reintroduction for conservation purposes, little is known about its efficiency. Here, we assessed the viability of reintroduction of the endangered migratory fish, Brycon orbignyanus, in an area of the Upper Uruguay River basin where the species has not been reported for more than 30 years. We released 4000 yearling juveniles in the Pelotas River in 2014 and maintained 400 juveniles in captivity as a control population. After three years, a total of 13 individuals was recaptured, of which, 10 were considered sexually mature with first maturation being recorded in animals larger than 42 cm in total body length. The age–length comparison with a control population growth curve showed that recaptured fish were slightly bigger than those in captivity. Furthermore, important ecological attributes as schooling behavior and dispersal capacity were recorded for all recaptured individuals. Combined, our results suggest that the re-establishment of a self-sustained population of locally extinct species B. orbignyanus in the Pelotas River may be successful if sustained over time and supported by conservation policies.


2021 ◽  
Vol 244 ◽  
pp. 02041
Author(s):  
B. Kamilov ◽  
M. Yuldashov ◽  
R. Khakimova ◽  
M. Ibodova

The study was carried out in 2014-2018 at the Tudakul reservoir, Uzbekistan. Samples included 278 European bream (Abramis brama), and 83 Amur white bream (Parabramis pekinensis). The age, total length and weight of the fish varied from 1 to 5 years, from 14 to 50 cm, from 30 to 1,405 g for the European bream and from 1 to 6 years, from 24 to 53.5 cm and 105 – 2,138 g for the white Amur bream and European bream, respectively. The relationship between total length (TL) and weight (W) is described by the equation W = 0.005 * TL3.2555 (r = 0.98) for European bream and W = 0.005 * TL3.201 (r = 0.96) for white Amur bream. Recovered average growth rate of European bream: TL1 - 13.5 cm; TL2 - 28.1 cm, TL3 - 37.95 cm, TL4 - 42.6 cm, TL5 - 48.6 cm.The average height of the Amur white bream: TL1 - 12.6 cm, TL2 - 23.3 cm, TL3 - 31.5 cm, TL4 - 37.9 cm, TL5 - 41.7 cm, TL6 - 44.2 cm. Lee’s phenomenon did not appear. All yearling fish were juvenile. In 2-year-old fish of both sexes of both species, the gonads were at stage II. Males and females of both species reached their first maturity at 3-4 years of age, when the total body length of the European bream was 30–32 cm, and the Amur white bream was 34–35 cm.


2011 ◽  
Vol 83 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Orlando N. Grillo ◽  
Sergio A.K. Azevedo

Missing data is a common problem in paleontology. It makes it difficult to reconstruct extinct taxa accurately and restrains the inclusion of some taxa on comparative and biomechanical studies. Particularly, estimating the position of vertebrae on incomplete series is often non-empirical and does not allow precise estimation of missing parts. In this work we present a method for calculating the position of preserved middle sequences of caudal vertebrae in the saurischian dinosaur Staurikosaurus pricei, based on the length and height of preserved anterior and posterior caudal vertebral centra. Regression equations were used to estimate these dimensions for middle vertebrae and, consequently, to assess the position of the preserved middle sequences. It also allowed estimating these dimensions for non-preserved vertebrae. Results indicate that the preserved caudal vertebrae of Staurikosaurus may correspond to positions 1-3, 5, 7, 14-19/15-20, 24-25/25-26, and 29-47, and that at least 25 vertebrae had transverse processes. Total length of the tail was estimated in 134 cm and total body length was 220-225 cm.


2021 ◽  
Vol 3 (2) ◽  
pp. 81-93
Author(s):  
Irwin Wahyudi ◽  
Deddy Bakhtiar ◽  
Ari Anggoro

Turtles are marine reptiles that are protected because of their endangered population. The Convention on International Trade in Endangered of Wild Flora and Fauna (CITES) stipulates seven species of sea turtles in the world into Appendix I as endangered, protected and not exploited in any form. The number of hatchlings that managed to reach the sea is currently difficult to know, one method that can be used to detect the presence of hatchlings in nature is by using the acoustic method. This study aims to analyze the backscatter characteristics of the turtle hatchlings and to determine the relationship between backscattering and body length of the turtle hatchlings. The benefits of this research are expected to be able to provide information about the value of backscatter and the relationship to the body length of hatchlings that can be used as a basis for estimating the stock or abundance of hatchlings in nature. This research was conducted in the waters of the Tapak Padri pond, Bengkulu City. The research implementation takes about 3 months, from August to October 2020. Acoustic data processing is carried out at the Marine Acoustic and Resource Exploration Laboratory, Marine Department, FMIPA, Sriwijaya University, Palembang. The results obtained are that the average value of TS ranges from -52.74 to -48.45 dB for hatchlings length of 7-9.3 cm. Based on the regression equation, the coefficient of determination (R2) obtained is 0.57, so it is known that the total length affects the target strength value by 57% and 43% is influenced by other factors. it can be concluded that there is a relationship between the total length of the hatchlings with the TS value of the hatchlings or the total length has an influence on the magnitude of the TS value in the hatchlings.


2020 ◽  
Vol 147 ◽  
pp. 02006
Author(s):  
Rury Nur Aini ◽  
Namastra Probosunu ◽  
Eko Setyobudi

This research aimed to know the length-weight relationship, condition factor, and otolith shape of marble goby (Oxyeleotris marmorata Blkr.) at Sermo Reservoir Yogyakarta. In total 211 samples (95 males and 116 females) were collected using gillnet and folded trap (bubu). Each sample was observed for sex determination, and then measured its total length, body weight, and otoliths diameter. The data were analyzed to determine the length and weight distribution, length-weight relationship, condition factor, and length-otolith diameter relationship. The result showed that the total length of the male was ranged 12.0-38.2 cm and female was ranged 12.2-44.5 cm. The weight of the male was ranged 21.0-704.8 g and female was ranged 21.1-1593.7 g. Both male and female have positive allometric growth with the equation W=0.0056L3.2894 for male and W=0.0051L3.311 for female. Condition factor was ranged 0.787-1.313 for male and 0.800-1.379 for female, and the majority of fish has a good condition (Kn ≥0.95 more than 50%). The shape of otolith edge was sinuate surrounded with regular wave-like curves, the diameter was increased in line with increasing of total body length by an equation of Y=0.2335+0.0248X (r=0.938).


2019 ◽  
Vol 1 (02) ◽  
pp. 64-67
Author(s):  
Meilisha Putri Pertiwi ◽  
Suci Siti Lathifah

Research on the condition of the nesting habitat of Chelonia mydas (green turtle) in Pangumbahan Beach, Ujung Genteng, South Sukabumi has been carried out. Data retrieval is done 6 times for 2 days, 27-28 November 2017 at 3 observation stations. The abiotic parameters measured include surface temperature and depth of 50 cm, surface humidity and depth of 50 cm, beach width, beach slope, and the size of sand grains. While the biotic parameters measured were density, relative density, the frequency of attendance, and distribution patterns of Pandanus tectorius (sea pandanus) vegetation. Based on the results of data processing, the biophysical conditions in Pangumbahan Beach are still suitable for the Chelonia mydas nesting habitat. It also got clear evidence of the many Chelonia mydas landings during the data collection.


2020 ◽  
Vol 13 (3) ◽  
pp. 585-591
Author(s):  
Luana Melo ◽  
Isabel Velasco ◽  
Julia Aquino ◽  
Rosangela Rodrigues ◽  
Edris Lopes ◽  
...  

Fibropapillomatosis is a neoplastic disease that affects sea turtles. It is characterized by multiple papillomas, fibropapillomas and cutaneous and/or visceral fibromas. Although its etiology has not been fully elucidated, it is known that there is a strong involvement of an alpha - herpesvirus, but the influence of other factors such as parasites, genetics, chemical carcinogens, contaminants, immunosuppression and ultraviolet radiation may be important in the disease, being pointed out as one of the main causes of a reduction in the green turtle population. Thus, the objective of this article was to describe the morphology of cutaneous fibropapillomas found in specimens of the green turtle (Chelonia mydas), using light and scanning electron microscopy in order to contribute to the mechanism of tumor formation. Microscopically, it presented hyperplastic stromal proliferation and epidermal proliferation with hyperkeratosis. The bulky mass was coated with keratin, with some keratinocyte invaginations, that allowed the keratin to infiltrate from the epidermis into the dermis, forming large keratinized circular spirals. Another fact that we observed was the influence of the inflammation of the tumors caused by ectoparasites.


2018 ◽  
Vol 17 (2) ◽  
pp. 169
Author(s):  
Luis G. Fonseca ◽  
Pilar Santidrián Tomillo ◽  
Wilbert N. Villachica ◽  
Wagner M. Quirós ◽  
Marta Pesquero ◽  
...  

2020 ◽  
Vol 27 (5) ◽  
pp. 245-256
Author(s):  
Cemil Aymak ◽  
Aşkın Hasan Uçar ◽  
Yusuf Katılmış ◽  
Eyup Başkale ◽  
Serap Ergene

In this study invertebrate infestation in green turtle (Chelonia mydas) nests were recorded for the first time for Kazanlı beach, Mersin, Turkey. For this aim, in 2006 nesting season, 294 natural intact green turtle nests were sampled to examine their contents and invertebrate infestation was found in 76 (25.85% of the total sampling green turtle nests). These infested nests were examined in terms of the invertebrate faunal composition. The specimens found in the green sea turtle nests were identified to order, family or genus levels and they were represented in 5 orders. These invertebrate groups are Elater sp. larvae (Elateridae; Coleoptera), Pimelia sp. larvae (Tenebrionidae; Coleoptera), Enchytraeidae (Oligochaeta), Cyrptostigmata (Acari), Oniscidae (Isopoda), Formicidae (Hymenoptera). Elater sp. was the most common invertebrate group in the green turtle nests. According to student t test, we found statistically significant differences between 7 independent variables and invertebrate species presence. Furthermore, logistic regression analysis explained that there is a negative relationship between hatching success rate and invertebrate species presence.


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