Kajian Struktur Ukuran Dan Parametr Populasi Kepiting Bakau (Scylla serrata) di Ekosistem Mangrove  Teluk Bintan, Kepulauan Riau

ABSTRAKKepiting bakau (Scylla serrata) merupakan salah satu potensi komoditas perikanan skala kecil yang memiliki nilai ekonomi tinggi. Kelimpahan populasi dipengaruhi oleh upaya penangkapan dan kondisi ekosistem mangrove sebagai habitat utamanya. Produksi kepiting bakau di Teluk Bintan menurun dan penyebabnya belum diketahui dengan pasti. Oleh karena itu, perlu dilakukan kajian tentang biologi kepiting bakau di Teluk Bintan. Penelitian ini bertujuan untuk mengkaji status populasi kepiting bakau yang meliputi struktur ukuran, parameter pertumbuhan dan laju mortalitas dan eksploitasi. Pengambilan data kepiting bakau dilakukan dengan pendekatan yaitu fisher-based survey. Hasil penelitian menunjukkan ukuran kepiting bakau yang tertangkap mulai dari lebar karapas (CW) 64-172 mm, ukuran fase muda kepiting jantan yang tertangkap mencapai 46,62% dan betina mencapai 48,06%, keduanya hampir setengah dari tangkapan total, ini menunjukkan bahwa alat tangkap yang digunakan belum selektif. CW∞ jantan mencapai 176,93 mm lebih tinggi dari kepiting betina sebesar 169,58 mm, namun sebaliknya nilai koefesien K jantan (0,360) lebih kecil dari betina (0,390), sehingga pertumbuhan kepiting bakau betina lebih cepat dari jantan. Perkiraan angka kematian alami (M) jantan = 0,5566 dan kematian akibat penangkapan (F) jantan = 0,6434 sedangkan M betina = 0,59 dan F betina = 0,41. Laju eksploitasi (E) kepiting jantan mencapai 53,62%, ini dapat dikatakan telah terjadi lebih tangkap atau over eksploitasi. Kata kunci: Scylla serrata, parameter pertumbuhan, struktur ukuran, mangrove and Teluk Bintan ABSTRACTMud crab (Scylla serrata) is one of the potential of small-scale fishery commodities that have high economic value. The abundance of the population is affected by the fishing effort and conditions mangrove ecosystem as its main habitat. Mud crab production in the Gulf of Bintan declined and the cause is not known with certainty. Therefore, it is necessary to study on the biology of mud crab in the Gulf of Bintan. This study aims to assess the status of mangrove crab population that includes the size structure, parameters of growth and the rate of mortality and exploitation. Data retrieval is done with a mangrove crab fisher-based survey. The results showed that the size of mud crab caught from carapace width (CW) 64-172 mm, the size of the young phase male crabs caught females reached 46.62% and reached 48.06%, both are almost half of the total catch, it indicates that fishing gear used is not selective. CW∞ males reach 176.93 mm higher than the female crabs of 169.58 mm, but instead value koefesien K males (0.360) is smaller than females (0.390), so that the growth of female mud crabs faster than males. Estimated natural mortality rates (M) male = 0.5566 and deaths from arrest (F) male = 0.6434 while M females female F = 0.59 and = 0.41. The rate of exploitation (E) male crabs reached 53.62%, can be said to have occurred over fishing or over-exploitation. Keywords: Scylla serrata, growth parameters, structure size, mangrove and bay Bintan

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Kajian Struktur Ukuran Dan Parametr Populasi Kepiting Bakau (Scylla serrata) di Ekosistem Mangrove Teluk Bintan, Kepulauan Riau

JURNAL BIOLOGI TROPIS ◽

10.29303/jbt.v15i2.158 ◽

2015 ◽

Vol 15 (2) ◽

Author(s):

M. Tahmid, Achmad Fahrudin Dan Yusli Wardiatno

Keyword(s):

Growth Parameters ◽

Economic Value ◽

Data Retrieval ◽

Fishing Effort ◽

Scylla Serrata ◽

Small Scale ◽

Natural Mortality ◽

Mud Crab ◽

Mangrove Crab ◽

The Status

ABSTRAKKepiting bakau (Scylla serrata) merupakan salah satu potensi komoditas perikanan skala kecilyang memiliki nilai ekonomi tinggi. Kelimpahan populasi dipengaruhi oleh upaya penangkapan dankondisi ekosistem mangrove sebagai habitat utamanya. Produksi kepiting bakau di Teluk Bintanmenurun dan penyebabnya belum diketahui dengan pasti. Oleh karena itu, perlu dilakukan kajiantentang biologi kepiting bakau di Teluk Bintan. Penelitian ini bertujuan untuk mengkaji statuspopulasi kepiting bakau yang meliputi struktur ukuran, parameter pertumbuhan dan laju mortalitasdan eksploitasi. Pengambilan data kepiting bakau dilakukan dengan pendekatan yaitu fisher-basedsurvey. Hasil penelitian menunjukkan ukuran kepiting bakau yang tertangkap mulai dari lebar karapas(CW) 64-172 mm, ukuran fase muda kepiting jantan yang tertangkap mencapai 46,62% dan betinamencapai 48,06%, keduanya hampir setengah dari tangkapan total, ini menunjukkan bahwa alattangkap yang digunakan belum selektif. CW∞ jantan mencapai 176,93 mm lebih tinggi dari kepitingbetina sebesar 169,58 mm, namun sebaliknya nilai koefesien K jantan (0,360) lebih kecil dari betina(0,390), sehingga pertumbuhan kepiting bakau betina lebih cepat dari jantan. Perkiraan angkakematian alami (M) jantan = 0,5566 dan kematian akibat penangkapan (F) jantan = 0,6434 sedangkanM betina = 0,59 dan F betina = 0,41. Laju eksploitasi (E) kepiting jantan mencapai 53,62%, ini dapatdikatakan telah terjadi lebih tangkap atau over eksploitasi.Kata kunci: Scylla serrata, parameter pertumbuhan, struktur ukuran, mangrove and Teluk BintanABSTRACTMud crab (Scylla serrata) is one of the potential of small-scale fishery commodities that havehigh economic value. The abundance of the population is affected by the fishing effort and conditionsmangrove ecosystem as its main habitat. Mud crab production in the Gulf of Bintan declined and thecause is not known with certainty. Therefore, it is necessary to study on the biology of mud crab in theGulf of Bintan. This study aims to assess the status of mangrove crab population that includes the sizestructure, parameters of growth and the rate of mortality and exploitation. Data retrieval is done witha mangrove crab fisher-based survey. The results showed that the size of mud crab caught fromcarapace width (CW) 64-172 mm, the size of the young phase male crabs caught females reached46.62% and reached 48.06%, both are almost half of the total catch, it indicates that fishing gearused is not selective. CW∞ males reach 176.93 mm higher than the female crabs of 169.58 mm, butinstead value koefesien K males (0.360) is smaller than females (0.390), so that the growth of femalemud crabs faster than males. Estimated natural mortality rates (M) male = 0.5566 and deaths fromarrest (F) male = 0.6434 while M females female F = 0.59 and = 0.41. The rate of exploitation (E)male crabs reached 53.62%, can be said to have occurred over fishing or over-exploitation.Keywords: Scylla serrata, growth parameters, structure size, mangrove and bay Bintan

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HABITAT QUALITY MUD CRAB (Scylla serrata) IN MANGROVE ECOSYSTEM OF BINTAN BAY, BINTAN DISTRIC, RIAU ISLANDS

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.29244/jitkt.v7i2.11025 ◽

2016 ◽

Vol 7 (2) ◽

Author(s):

M. Tahmid ◽

Achmad Fahrudin ◽

Yusli Wardiatno

Keyword(s):

Body Weight ◽

Data Collection ◽

Habitat Quality ◽

Carapace Width ◽

Mangrove Ecosystem ◽

The Body ◽

Scylla Serrata ◽

Small Scale ◽

Mud Crab ◽

Index Value

Mud crab (Scylla serrata) is one of small scale fisheries commodity that have high economic value and typically associated with good mangrove ecosystem. A habitat degradation will cause a serious impact on the existence of mud crab population. The puropse of this study was to assess the ecological quality of mud crab habitat condition on Bintan Bay’s mangrove ecosystem. Ecological data collection was conducted by using plots line transect for mangrove and the mud carb data collection by using fishermen catch (fisher based survey). The results showed the value of habitat quality index (HQI) of mud crab (Scylla serrata) ranged from 52-82 which mean in the “moderate” category (index value 43-66) and "good" (index value 67-90). It showed that Bintan Bay’s mangrove ecosystems was good enough to support the viability of mud crab. Habitat quality had a linier impact on body weight gain (R2 = 99.78%) and carapace width (R2= 99.21%). This showed that higher the index value of habitat quality, the size of the body weight and carapace width will increases. Keywords: Scylla serrata, habitat quality, ecology, mangroves, and Bintan Bay

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PARAMETER POPULASI DAN TINGKAT PEMANFAATAN KEPITING BAKAU (Scylla serrata Forsskal, 1775) DI PERAIRAN SEBATIK, KALIMANTAN UTARA

Jurnal Penelitian Perikanan Indonesia ◽

10.15578/jppi.24.3.2018.187-196 ◽

2018 ◽

Vol 24 (3) ◽

pp. 187

Author(s):

Tirtadanu Tirtadanu ◽

Umi Chodrijah

Keyword(s):

Growth Parameters ◽

Carapace Width ◽

Fishing Effort ◽

Scylla Serrata ◽

Von Bertalanffy ◽

Population Parameters ◽

Mud Crab ◽

Female Crab ◽

Male Crab ◽

Exploitation Rate

Salah satu informasi yang diperlukan untuk merumuskan pengelolaan kepiting bakau (Scylla serrata Forsskal, 1775) yang berkelanjutan adalah parameter populasi dan tingkat pemanfaatannya. Penelitian ini bertujuan untuk mengkaji parameter populasi dan tingkat pemanfaatan kepiting bakau di perairan Sebatik. Penelitian dilakukan pada Maret-Desember 2017. Sampel kepiting bakau di peroleh dari hasil tangkapan nelayan dengan alat tangkap bubu di perairan Sebatik. Pertumbuhan dianalisis berdasarkan persamaan Von Bertalanffy dengan mengamati pergeseran struktur ukuran kepiting tiap bulan dan tingkat pemanfaatan diperoleh dari metode kurva konversi panjang dengan hasil tangkapan. Hasil penelitian menunjukkan kepiting bakau yang tertangkap bubu di perairan Sebatik berukuran lebar karapas (carapace width) antara 84-144 mmCW dengan rata-rata ukuran yang tertangkap adalah 107,05±12,3 mmCW pada kepiting jantan dan 110,2±8,86 mmCW pada kepiting betina. Pertumbuhan berat kepiting bakau jantan lebih cepat dibandingkan ukurannya (b=3,6) sebaliknya pertumbuhan berat kepiting bakau betina lebih lambat dibandingkan ukurannya (b=2,5). Nisbah kelamin kepiting bakau menunjukkan kondisi tidak seimbang (5,5 : 1) dengan proporsi jantan lebih dominan dibandingkan betina. Lebar karapas asimptotik (CW) kepiting bakau jantan adalah 151,2 mmCW dan betina adalah 140,5 mmCW. Laju pertumbuhan (K) kepiting bakau adalah 0,75 tahun-1 pada kepiting jantan dan 0,79 tahun-1 pada kepiting betina. Status pemanfaatan kepiting bakau telah berada dalam tahapan mendekati lebih tangkap (E=0,5-0,55) sehingga disarankan tidak melakukan penambahan upaya penangkapan kepiting bakau di perairan Sebatik. One of the information needed for formulating the sustainable management of mud crab is the availability of information on the population parameters and its exploitation rate. The current research aimed to study the population parameters and the exploitation rate of mud crab in Sebatik Waters. Field research was conducted in March – December 2017. Samples of mud crab were obtained from the catch of fisherman by trap in Sebatik Waters. The Von Bertalanffy growth parameters were constructed through monthly modals progression analysis of the size of carapace width frequencies distributions and the exploitation rate was estimated through the method of length converted catch curve. The results showed that the carapace width of mud crabs caught by trap in Sebatik Waters ranged between 84 to 144 mmCW with the mean size of 107.05±12.3 mmCW for male and 110.2±8.86 mmCW for female. The growth of weights of male crab (b=3.6) is faster than its size, while the growth of weight of female crab was slower than its size (b=2,5). The sex ratio of mud crab was unbalanced (5.5 : 1) that the proportion of male was more dominant than female. Asymptotic carapace width (CW) of mud crab was 151.2 mmCW for male and 140.5 mmCW for female. The growth rate (K) of mud crab was 0.75 year-1 for male and 0.79 year-1 for female. The exploitation status of mud crab was starting to overfishing (E=0,5-0,55) so it suggest to not increase the fishing effort of mud crab fishery in Sebatik Waters.

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HABITAT QUALITY MUD CRAB (Scylla serrata) IN MANGROVE ECOSYSTEM OF BINTAN BAY, BINTAN DISTRIC, RIAU ISLANDS

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.28930/jitkt.v7i2.11025 ◽

2016 ◽

Vol 7 (2) ◽

Cited By ~ 1

Author(s):

M. Tahmid ◽

Achmad Fahrudin ◽

Yusli Wardiatno

Keyword(s):

Body Weight ◽

Data Collection ◽

Habitat Quality ◽

Carapace Width ◽

Mangrove Ecosystem ◽

The Body ◽

Scylla Serrata ◽

Small Scale ◽

Mud Crab ◽

Index Value

Mud crab (Scylla serrata) is one of small scale fisheries commodity that have high economic value and typically associated with good mangrove ecosystem. A habitat degradation will cause a serious impact on the existence of mud crab population. The puropse of this study was to assess the ecological quality of mud crab habitat condition on Bintan Bay’s mangrove ecosystem. Ecological data collection was conducted by using plots line transect for mangrove and the mud carb data collection by using fishermen catch (fisher based survey). The results showed the value of habitat quality index (HQI) of mud crab (Scylla serrata) ranged from 52-82 which mean in the “moderate” category (index value 43-66) and "good" (index value 67-90). It showed that Bintan Bay’s mangrove ecosystems was good enough to support the viability of mud crab. Habitat quality had a linier impact on body weight gain (R2 = 99.78%) and carapace width (R2= 99.21%). This showed that higher the index value of habitat quality, the size of the body weight and carapace width will increases. Keywords: Scylla serrata, habitat quality, ecology, mangroves, and Bintan Bay

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Carapace length-weight and width-weight relationships of Scylla serrata in Bulungan District, North Kalimantan, Indonesia

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d180405 ◽

2017 ◽

Vol 18 (4) ◽

pp. 1316-1323 ◽

Cited By ~ 1

Author(s):

BAMBANG WIDIGDO ◽

RUKISAH RUKISAH ◽

ASBAR LAGA ◽

AGUS A. HAKIM ◽

YUSLI WARDIATNO

Keyword(s):

Sex Ratio ◽

Carapace Length ◽

Carapace Width ◽

Mangrove Ecosystem ◽

Scylla Serrata ◽

Mud Crab ◽

B Values ◽

Mangrove Ecosystems ◽

Length Width ◽

Male To Female

Widigdo B, Rukisah, Laga A, Hakim AA, Wardiatno Y. 2017. Carapace length-weight and width-weight relationships of Scylla serrata in Bulungan District, North Kalimantan, Indonesia. Biodiversitas 18: 1316-1323. The mud crab, Scylla serrata lives associated with mangrove ecosystems and is widely distributed in the Indo West-Pacific. The present work was aimed to reveal the carapace length/width-weight relationships of Scylla serrata in two mangrove ecosystem area of Bulungan District, North Kalimantan- Indonesia, i.e. Kahayan Delta and Tibi Island. The crabs were collected by using ambau pancang (trap) for two months from November to December 2016. A total of 522 individuals were collected and their carapace length, carapace width, and weight were measured. The sex ratio of total collected samples (male to female) was 1:0.79. Carapace length and width of S. serrata caught in these two study area ranged from 40 to 89 mm for male; 32 to 91 mm for female and 59 to 128 mm for male; 53 to 122 mm for female, respectively. The carapace length-weight relationships of total samples showed logarithmic equations as follow: W = -3.2194 + 2.9725 Log CL for male and Log W = -2.2010 + 2.3750 Log CL for female. While the carapace width-weight relationships are as follow: W = -3.9162 + 3.1012 Log CW for male and Log W = -2.6001 + 2.3968 Log CW for female. The b values of carapace width-weight relationship indicated that the growth pattern of male was positive allometric and female was negative allometric. Size frequency of crab population is also presented.

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Estimated growth of the mud crab Scylla olivacea in the Ranong mangrove ecosystem, Thailand, based on a tagging and recapture study

Marine and Freshwater Research ◽

10.1071/mf01048 ◽

2002 ◽

Vol 53 (7) ◽

pp. 1083 ◽

Cited By ~ 21

Author(s):

S. M. Moser ◽

D. J. Macintosh ◽

S. Pripanapong ◽

N. Tongdee

Keyword(s):

Transition Matrix ◽

Carapace Width ◽

Mangrove Ecosystem ◽

Small Scale ◽

Mud Crab ◽

Estimation Of Parameters ◽

Final Size ◽

Baited Traps ◽

In Captivity ◽

Males And Females

Growth of the mud crab Scylla olivacea in the Ranong mangrove ecosystem was estimated using a size-transition matrix. Male (n = 1284) and female (n = 1069) mud crabs were tagged with externally visible and numbered T-tags and then released. Tagged crabs caught by commercial small-scale fishermen were measured and re-released. Data from 664 male and 463 female recaptures were obtained in total. Moult increment in the investigated size range (5–13 cm external carapace width) was independent of size and sex. The size distribution of mud crab moult increments was fitted to a normal distribution, resulting in a mean moult increment of 1.67 ± 0.48 cm (s.d.). This result was used to estimate the proportion of males and females moulting, and the selectivity of the baited traps used to catch them. Trap selectivity among the tagged crabs was uniform for both male and female crabs. Also, the proportion of those moulting decreased with size in the same manner for both sexes. The predictions of growth from the final size-transition matrix were in agreement with the observed growth of a subset of tagged crabs not used in the estimation of parameters in the size-transition matrix and growth of crabs reared in captivity over a period of 2 months.

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KARAKTERISTIK POPULASI DAN TINGKAT PEMANFAATAN KEPITING BAKAU (Scylla serrata Forskal 1775) DI PERAIRAN ASAHAN DAN SEKITARNYA, SUMATERA UTARA

Jurnal Penelitian Perikanan Indonesia ◽

10.15578/jppi.24.3.2018.165-174 ◽

2018 ◽

Vol 24 (3) ◽

pp. 165

Author(s):

Andina Ramadhani Putri Pane ◽

Ali Suman

Keyword(s):

Mortality Rate ◽

Stock Assessment ◽

Carapace Width ◽

Total Mortality ◽

Population Characteristics ◽

Assessment Tools ◽

Scylla Serrata ◽

Mud Crab ◽

Length Frequency ◽

Mangrove Crab

Peningkatan jumlah ekspor kepiting (Scylla serrata Forskal, 1775) di wilayah perairan Asahan memacu peningkatan penangkapan yang dapat berpengaruh terhadap populasi dan kelestarian. Penelitian ini bertujuan untuk mengetahui karakteristik populasi dan tingkat pemanfaatan kepiting bakau di perairan Asahan dan sekitarnya. Pengambilan sampel dilakukan setiap bulan dari Januari sampai dengan Nopember 2016 di tempat pendaratan kepiting oleh enumerator. Data dianalisa dengan metode Electronic LEngth Frequency Analisys-I (ELEFAN-I) dari FAO-ICLARM Stock Assessment Tools II (FiSAT II). Hasil penelitian menunjukkan pola pertumbuhan kepiting bakau bersifat allometrik negatif pada kisaran lebar karapas antara 85 - 175 mm dan bobot tubuh 127 – 1.152,5 gram. Rata-rata ukuran lebar karapas tertangkap dengan jaring dan bubu adalah 118,6 mm dan ukuran matang gonad pertama kali adalah 120,6 mm. Laju pertumbuhan (K) 1,38 per tahun dan lebar karapas maksimum (CW) sebesar 201 mm. Laju kematian total (Z) sebesar 3,59 per tahun, laju kematian karena penangkapan (F) dan laju kematian alami (M) masing-masing 2,27 per tahun dan 1,32 per tahun. Laju pemanfaatan (E) kepiting bakau di perairan Asahan adalah 0,63 per tahun atau sudah melebihi nilai optimum penangkapan. Agar sumber daya kepiting terjamin kelestariannya, maka harus dilakukan pengurangan upaya penangkapan sekitar 26 %.Increase in the volume of giant mud crab exports (Scylla serrata Forskal, 1775) in the Asahan waters stimulate the increasing catches that affect population and sustainability. This study aims to determine the population characteristics and the exploitation level of giant mud crab in Asahan and adjacent waters. Monthly sampling was done from January to November 2016 at crab landing sites by enumerator. The data were analyzed using Electronic Length Frequency Analysys-I (ELEFAN-I) method available in FAO-ICLARM Stock Assessment Tools II (FiSAT II) program. The results showed that the growth pattern of giant mud crab was negative allometric with carapace width between 85 - 175 mm and individual body weight 127 - 1,152.5 grams. The average carapace’s width caught by net and trap was 118.6 mm and the size of gonad first maturity was 120.6 mm. Growth rate (K) 1.38 per year and maximum carapace width (CW) of 201 mm. Total mortality rate (Z) of 3.59 per year, mortality rate due to fishing (F) and natural mortality rate (M) was 2.27 per year and 1.32 per year respectively. The rate of exploitation (E) of mangrove crab in Asahan waters was 0.63 or has exceeded the optimum value. For the sustainability of crab resource a reduction of 26% in fishing effort is suggested.

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POPULATION BIOLOGY OF MUD CRAB Scylla serrata - Forsskal, 1775 IN MANGROVE ECOSYSTEM OF SUBANG DISTRICT, WEST JAVA

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.28930/jitkt.v9i1.17928 ◽

2017 ◽

Vol 9 (1) ◽

pp. 173

Author(s):

Ayu Annisa Kumalah ◽

Yusli Wardiatno ◽

Isdradjad Setyobudiandi ◽

Achmad Fahrudin

Keyword(s):

Population Dynamics ◽

Size Distribution ◽

Population Biology ◽

Stock Assessment ◽

Mangrove Ecosystem ◽

Mature Female ◽

Scylla Serrata ◽

Mud Crab ◽

Growth Coefficient ◽

Exploitation Rate

The study of population biology of mud crab Scylla serrata is necessary to analyse the population dynamics, such as growth of crabs, size distribution, mortality and exploitation rates of S. serrata. Population biology data collection was carried out from March to June 2016 at estuary and silvofishery areas of three stations (Mayangan, Tanjung Tiga and Blanakan villages). Data were analyzed using analytical methods of FISAT-II (FAO-ICLARM Stock Assessment Toool II)instruments. The results showed the growth of S. serrata male in Subang distric was positive allometric and the female was negative allometric. Growth coefficient (K) ranged from 0.21 to 0.43 in the estuary and from 0.28 to 0.89 in silvofishery area. Exploitation rate in the silvofishery area has been above the maximum exploitation rate. The size distribution of S. serrata in Subang district has the highest frequency at class interval of 106-110 mm (male) and of 101-105 mm. The highest abundance of mature female crabs is in May.Keywords : population biology, Scylla serrata, Subang District

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Utilization of Trash Fish for Cultivation of Crablet Mud Crab (Scylla serrata)

ILMU KELAUTAN Indonesian Journal of Marine Sciences ◽

10.14710/ik.ijms.25.3.110-114 ◽

2020 ◽

Vol 25 (3) ◽

pp. 110-114

Author(s):

Heppi Iromo ◽

Dori Rachmawani ◽

Abdul Jabarsyah ◽

Zainuddin Zainuddin

Keyword(s):

Carapace Width ◽

Survival Rates ◽

Scylla Serrata ◽

Mud Crab ◽

Growth And Survival ◽

Weight Growth ◽

Randomized Design ◽

Trichiurus Lepturus ◽

Trash Fish ◽

In The Wild

The high demand for mud crabs in North Kalimantan causes catch to increase in the wild. If it is not balanced with efforts to increase its aquaculture of mud crab, in the future there will be a decline in population. This study aims to determine the growth and survival rate of mud crab seed (crablet, Scylla serrata) in the application method of different types of trash fish. This research used a completely randomized design with 4 treatments and 3 replications. The Crablet used carapace width average 0.07-0.09 cm and weigh average 0.05-0.07 g with total 150 crablets. The treatments applied by trash fish were (A) Tilapia Fish (Oreochromis mossambicus), (B) Longfin Herrings Fish (Ilisha elongata), (C) Sword Fish (Trichiurus lepturus) and (D) Snails (Telescopium telescopium). The results were The best weight growth of crablet occurs in the treatment of T. lepturus (P>0.05) and the highest of survival rates of crablet were found in treatment T. telescopium (P<0.05) than the other. The trash fish were used turned out to be able survival of crablet mud crab (Scylla serrata).

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The population and mortality characteristics of mangrove crab (Scylla serrata) in the mangrove ecosystem of Tarakan City, Indonesia

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d210855 ◽

2020 ◽

Vol 21 (8) ◽

Author(s):

AGUS INDARJO ◽

Gazali Salim ◽

MUFRIDA ZEIN ◽

DODDY SEPTIAN ◽

STEPHANIE BIJA

Keyword(s):

Carapace Length ◽

Total Mortality ◽

Condition Index ◽

Mangrove Ecosystem ◽

Scylla Serrata ◽

Primary Data ◽

Allometric Growth ◽

Male And Female ◽

Mangrove Crab ◽

Mangrove Crabs

Abstract. Indarjo A, Salim G, Zein M, Septian D, Bija S. 2020. The population and mortality characteristics of mangrove crab (Scylla serrata) in the mangrove ecosystem of Tarakan City, Indonesia. Biodiversitas 21: 3856-3866. The mangrove crab is an iconic species of Tarakan City and is often is used as a souvenir. However, the high demand for this species can cause its population to decline. This study aimed to characterize the mangrove crab (Scylla serrata) population in the mangrove ecosystem of Tarakan City, North Kalimantan, Indonesia. This study was designed using a quantitative descriptive method with a case study model. The samples of mangrove crabs were obtained from 6 different stations using a purposive sampling method. The mangrove crab specimens were caught using 35-50 units of crab traps known as the ambau brackets. The primary data included carapace length, carapace width, carapace thickness, sex, and the total weight of each mangrove crab specimen. The results showed that male mangrove crabs have positive allometric growth when the condition index was fat. However, female crabs exhibited negative allometric growth when the condition index was thin. The Von Bertalanffy growth model analysis showed that the maximum carapace length of male mangrove crab in the mangrove ecosystem of Tarakan City was approximately 11.1118 cm for 189 days, while the female length was 9.6474 cm for 80 days. The total mortality value of male and female crabs was 120.01% and 154.94%, the mortality due to fishing was 84.69% and 135.75%, and natural mortality was 35.32% and 19.2%, respectively. The estimated rate of exploitation of both male and female crabs was 70.57% and 87.61%, respectively. The exploitation of S. serrata in the mangrove ecosystem of Tarakan City was evident, hence, conservation efforts are urgently required.

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