scholarly journals Karakteristik Bioekologi Rajungan (Portunus Pelagicus) Di Perairan Dusun Ujung Lombok Timur

2016 ◽  
Vol 16 (2) ◽  
Author(s):  
Didik Santoso ◽  
Ahmad Raksun ◽  
Karnan . ◽  
Lalu Japa
Keyword(s):  
Ph Value ◽  
Survey Methods ◽  
Carapace Width ◽  
Wide Distribution ◽  
Habitat Characteristics ◽  
Portunus Pelagicus ◽  
Male Crab ◽  
Water Ph ◽  
Males And Females ◽  
Ecological Parameters

ABSTRAK Penelitian ini bertujuan untuk mengkaji ukuran rajungan yang tertangkap, menganalisis perbandingan jumlah rajungan jantan dan betina yang tertangkap, dan  menganalisis karakteristik habitat (salinitas, suhu, pH, dan bentuk dasar substrat perairan) di daerah penangkapan rajungandi Dusun Ujung Lombok Timur. Jenis penelitian ini adalah penelitian diskriptif dengan menggunakan metode survai dalam pengambilan data. Parameter yang diteliti adalah parameter biologi dan ekologi rajungan. Parameter biologi yang diamati adalah  jenis kelamin, dan lebar karapas, sedangkan parameter ekologi adalah suhu, salinitas, dan pH perairam serta bentuk dasar substrat. Kondisi substrat didominasi oleh fraksi pasir diikuti oleh fraksi lumpur dan fraksi liat. Hasil penelitian menunjukkan bahwa kualitas air di daerah penelitian sangat sangat layak bagi kehidupan rajungan, dengan sebaran suhu antara 290C – 300C. Salinitas perairan di daerah penelitian berkisar dari 31 sampai 32  ppt, dan Nilai pH perairan di lokasi penelitian berkisar antara 7.2 sampai 7.5. Distribusi lebar karaps rajungan di dominasi oleh lebar diatas 100 mm baik jantan maupun betina. Proporsi lebar karapas rajungan jantan yang tertangkap dengan lebar diatas 100 mm adalah sebesar 41,7% dan betina sebesar 48,3% dari total sampel penelitian. Nisbah kelamin antara rajungan jantan dan betina adalah 0,8 : 1. Hal ini menunjukkan bahwa rajungan jantan dapat membuahi lebih dari satu rajungan betina.Kata-Kata Kunci: Bio-ekologi, diskriptif, karakteristik habitatABSTRACTThis study aims to assess the size of the crabs are caught, analyzing the ratio of male and female, and analyze the habitat characteristics (salinity, temperature, pH, and form of the substrate waters) in crab fishing area in the Ujung Vilage of East Lombok District.This research is a descriptive study using survey methods in data collection.The parameters studied are biological and ecological parameters. Biological parameters measured were sex and carapace width, while the ecological parameters are temperature, salinity, and pH of the water and the form of the substrate.The results showed that the water quality in the study area were very feasible for the life of crab, with a distribution of temperature between 290C - 300C.Salinity waters in the study area ranged from 31 to 32 ppt, and water pH value in the study site ranged from 7.2 to 7.5.Karaps wide distribution crab dominated by width exceeding 100 mm in both males and females. The proportion of carapace width of male crabs are caught with a width exceeding 100 mm is 41.7% and females at 48.3% of the total sample.Rajungan sex ratio between males and females was 0.8: 1. This shows that the male crab can fertilize more than one female crabs. Keywords: Bio-ekologi, descriptive, habitat characteristics

Biologi Rajungan Portunus pelagicus Linnaeus, 1758 (Crustacea: Portunidae) Ditinjau Dari Aspek Distribusi Ukuran Dan Parameter Pertumbuhan Di Perairan Rembang, Jawa Tengah

2019 ◽  
Vol 8 (4) ◽  
pp. 402-408
Author(s):  
Nathanael Ganang Anindityo Wibowo ◽  
Chrisna Adhi Suryono ◽  
Ibnu Pratikto
Keyword(s):  
Size Structure ◽  
Carapace Width ◽  
Growth Parameter ◽  
Survey Method ◽  
Average Weight ◽  
Swimming Crab ◽  
Female Crab ◽  
Potential Yield ◽  
Portunus Pelagicus ◽  
Male Crab

Rembang merupakan salah satu kabupaten di Jawa Tengah yang dikenal sebagai daerah penghasil sumberdaya rajungan yang cukup tinggi permintaannya dan terus meningkat setiap tahunnya. Hal tersebut dapat menyebabkan terjadinya penurunan potensi hasil rajungan akibat intensifnya penangkapan di Perairan Rembang. Kajian tentang kondisi stok sumberdaya rajungan  terkait sebaran dan dinamika populasi ini sangat diperlukan dalam pengelolaan potensi rajungan. Tujuan dari penelitian ini adalah untuk menganalisis struktur ukuran dan parameter pertumbuhan rajungan di Perairan Rembang. Penelitian ini dilaksanakan pada bulan Maret – Juni 2019 di Perairan Rembang, dengan menggunakan metode survei yang bersifat deskriptif. Total sampel rajungan selama penelitian adalah 1200 ekor yang terdiri dari 574 ekor jantan dan 624 ekor betina. Hasil penelitian menunjukkan kelas ukuran lebar karapas rajungan didominasi oleh rajungan muda, dengan rata – rata 105.01 ± 11.99 mm untuk jantan dan 107.73 ± 10.68 untuk betina. Berat rata – rata rajungan jantan yaitu sebesar 95.2 ± 27.1 gram dan rajungan betina sebesar 97.9 ± 23.1 gram, sehingga menunjukkan rajungan jantan lebih kecil dibandingkan dengan rajungan betina. Pola pertumbuhan rajungan di Perairan Rembang bersifat allometrik negatif. Laju pertumbuhan rajungan di Perairan Rembang yang didapatkan adalah berupa nilai panjang asimptotik (L∞) sebesar 71.4 mm dengan koefisien pertumbuhan (K) sebesar 1.5/tahun.Rembang is a coastal region in Central Java which known as to producer of blue swimming crab resources that are in high demand and continues to increase every year. It will because decreasing the potential yield of blue swimming crab due to intensive fishing in Rembang Waters. Study on the stock condition of the blue swimming crab resource related to the distribution and dynamics of the population is required for the management of the blue swimming crab potential. The current research aims to assess the size structure and growth parameter of blue swimming crab in the Rembang Waters. The research was conducted from March to June 2019 in Rembang Waters, using a descriptive survey method. The total number of crab samples during the study was 1200 animals consisting of 574 male and 624 female. The results showed that the size of the crab carapace width class was dominated by young crabs, with an average of 105.01 ± 11.99 mm for males and 107.73 ± 10.68 for females. The average weight of male crab is 95.2 ± 27.1 gram and female crab is 97.9 ± 23.1 gram, indicates that male crab is smaller than female crab. The crab’s growth in Rembang Waters is allometric negative. The growth rate of crab in the Rembang Waters obtained is in the form of asymptotic length (L∞) was 71.4 mm with a growth coefficient (K) 1.5/year.

scholarly journals VARIABILITY OF CARAPACE WIDTH SIZE AND ABUNDANCE OF BLUE SWIMMING CRABS (Portunus pelagicus Linnaeus) IN PATI WATERS

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Dyah Ika Nugraheni ◽  
Achmad Fahrudin ◽  
. Yonvitner
Keyword(s):  
Coastal Waters ◽  
Accretion Rate ◽  
Carapace Width ◽  
Management Strategies ◽  
Fishing Effort ◽  
Swimming Crab ◽  
Nearshore Zone ◽  
Portunus Pelagicus ◽  
Males And Females ◽  
Swimming Crabs

<p><em>Fishing effort enhancement would put pressure on blue swimming crab resources and its ecosystem. The objective of this study was to determine the spatial distribution based on the size of the carapace width (CW), abundance, temperature, salinity, depth, and fishing intensity in Pati waters which was divided into two zones (zones 1=nearshore, zone 2=offshore). The result showed that the average of carapace width in zone 1 to zone 2 was significantly different (p &lt;0.05), as well as between males and females. Average number of individual (abundance) was significantly different according to fishing areas and sex (p &lt;0.05). The average of water temperature in zone 1 was higher than in zone 2, salinity in zone 1 was smaller than in zone 2, and the water depth in zone 1 was shallower than in zone 2. The higher the crab catch intensity leaded to the smaller the abundance and size of carapace width. Alternative management strategies were proposed such as to divert fishing grounds from coastal waters to offshore during low productivity season, to uphold rules on minimum legal size for catching (Lm = 107 mm),  to release of berried females catch, and to reduce accretion rate of gear and fishing fleet mainly in the coastal zone waters.</em></p><p><em><strong><em>Keywords:  </em></strong><em>blue swimming crab, carapace widht (CW), abundance, intensity of fishing</em></em></p>

scholarly journals VARIABILITY OF CARAPACE WIDTH SIZE AND ABUNDANCE OF BLUE SWIMMING CRABS (Portunus pelagicus Linnaeus) IN PATI WATERS

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Dyah Ika Nugraheni ◽  
Achmad Fahrudin ◽  
. Yonvitner
Keyword(s):  
Coastal Waters ◽  
Accretion Rate ◽  
Carapace Width ◽  
Management Strategies ◽  
Fishing Effort ◽  
Swimming Crab ◽  
Nearshore Zone ◽  
Portunus Pelagicus ◽  
Males And Females ◽  
Swimming Crabs

Fishing effort enhancement would put pressure on blue swimming crab resources and its ecosystem. The objective of this study was to determine the spatial distribution based on the size of the carapace width (CW), abundance, temperature, salinity, depth, and fishing intensity in Pati waters which was divided into two zones (zones 1=nearshore, zone 2=offshore). The result showed that the average of carapace width in zone 1 to zone 2 was significantly different (p <0.05), as well as between males and females. Average number of individual (abundance) was significantly different according to fishing areas and sex (p <0.05). The average of water temperature in zone 1 was higher than in zone 2, salinity in zone 1 was smaller than in zone 2, and the water depth in zone 1 was shallower than in zone 2. The higher the crab catch intensity leaded to the smaller the abundance and size of carapace width. Alternative management strategies were proposed such as to divert fishing grounds from coastal waters to offshore during low productivity season, to uphold rules on minimum legal size for catching (Lm = 107 mm),  to release of berried females catch, and to reduce accretion rate of gear and fishing fleet mainly in the coastal zone waters.Keywords:  blue swimming crab, carapace widht (CW), abundance, intensity of fishing

Studies on reproductive biology and ecology of blue swimming crab Portunus pelagicus from Chilika Lagoon, Orissa, India

2010 ◽  
Vol 91 (1) ◽  
pp. 257-264 ◽  
Author(s):  
D. Sahoo ◽  
S. Panda ◽  
B.C. Guru
Keyword(s):  
Gonadosomatic Index ◽  
Carapace Width ◽  
Food Habit ◽  
Total Body Weight ◽  
Fish Bone ◽  
Chilika Lagoon ◽  
Portunus Pelagicus ◽  
Commercially Important ◽  
Total Body ◽  
The Relationship

Portunus pelagicus a commercially important crab species found in Chilika lagoon constitutes about 20% of the total crab production. The carapace width (CW) ranges from 4.5–10.5 cm in both the sexes during the study period. The maximum abundance of male was at 6.6 to 7.5 cm CW whereas the females predominate from 6.6 to 9.5 cm CW. The relationship between carapace length (CL) and CW is linear in both sexes which indicates isometric growth. However, the relationship between CL, CW with total body weight (TW) is exponential. The food habit from gut content analysis shows that the species is highly carnivorous and the main food items include prawn carapace and appendages (27.58%), molluscan remaining (21.55%), fish bone (7.75%), seagrass (1.72%), unidentified materials (4.31%) and the mixed food (37.06%). The feeding index was found highest (80.95%) in February whereas it is lowest (60.9%) in June. The mature females are observed from May to July with a peak in July in the lagoon. The highest gonadosomatic index is found in July with an average CW of 10.5 cm. No berried females are found in the study period, which indicates that it did not spawn inside the lagoon and migrates to the sea during the rainy season.

Aspects of reproduction, and morphology of the penis, of Pseudantechinus woolleyae (Marsupialia : Dasyuridae)

2017 ◽  
Vol 65 (6) ◽  
pp. 357 ◽  
Author(s):  
P. A. Woolley
Keyword(s):  
Western Australia ◽  
Arid Regions ◽  
Wide Distribution ◽  
Erectile Tissue ◽  
Australian Museum ◽  
Seasonal Breeder ◽  
Males And Females ◽  
One Year ◽  
Western Australian

Woolley’s Pseudantechinus, P. woolleyae, has remained virtually unstudied in the 30 years since its recognition in 1988 as a species distinct from P. macdonnellensis. It has a wide distribution in arid regions of Western Australia. What little is known of its biology comes largely from studies carried out over the years 1988–91 on one wild-caught female and her offspring, and a few specimens held in the collection of the Western Australian Museum. P. woolleyae is a seasonal breeder and young are born from late July to early October. They mature when ~7 months old. Both males and females are potentially capable of breeding in more than one year. Males have accessory erectile tissue that does not form an appendage on the penis.

scholarly journals A multivariate study of variation in two species of rock crab of the genus Leptograpsus

1974 ◽  
Vol 22 (3) ◽  
pp. 417 ◽  
Author(s):  
NA Campbell ◽  
RJ Mahon
Keyword(s):  
Carapace Length ◽  
Carapace Width ◽  
The Body ◽  
Canonical Variate ◽  
Multivariate Approach ◽  
Maximum Width ◽  
Multivariate Study ◽  
Rock Crab ◽  
Males And Females ◽  
Colour Form

A multivariate approach has been used to study morphological variation in the blue and orange-form species of rock crab of the genus Leptograpsus. Objective criteria for the identification of the two species are established, based on the following characters: width of the frontal region of the carapace; width of the posterior region of the carapace (rear width); length of the carapace along the midline; maximum width of the carapace; and the depth of the body. The first canonical variate, which differentiates between the two species, represents a contrast between the carapace width relative to the width of the front lip and the depth of the body; the blue-form species has a greater relative carapace width than has the orange form. The second canonical variate, which presents a contrast between the rear width and the carapace length, identifies males and females within each species; males have a greater relative carapace length than have females. All individuals, including 20 not used in the study, were correctly identified for colour form. The clear separation of the blue and orange forms achieved by canonical analysis supports the previously determined specific status of the two forms.

scholarly journals Development of a Low-Cost pH Meter for Liquid Chemical Fertilizers

2020 ◽  
Vol 8 (4) ◽  
pp. 840-846
Author(s):  
Muhittin Yağmur Polat ◽  
Abdullah Beyaz ◽  
İbrahim Çilingir
Keyword(s):  
Ph Value ◽  
Low Cost ◽  
Ph Sensor ◽  
Field Application ◽  
Average Error ◽  
Chemical Fertilizers ◽  
Modern Agriculture ◽  
Ph Values ◽  
Water Ph ◽  
Liquid Chemical

Liquid chemical fertilizers are widely used in modern agriculture. The pH values of these fertilizers are important in terms of their effectiveness in the field application and their effect on the soil-water pH balance. Therefore, it is necessary to measure the pH and other properties of liquid fertilizers with fast, practical and inexpensive methods. With the advancing technology, pH value has been started to measure more accurately and efficiently with the help of low-cost devices. In this study, a low-cost pH meter was developed using a low-cost pH sensor, an Arduino UNO R3 microcontroller board, and a software written in the C/C++ programming language. The developed pH meter was used to measure the pH values of liquid chemical fertilizers. Close variations were observed between the values obtained from it and the values measured by an accredited, laboratory-type pH meter. According to the pH measurements of the two pH meters, R2 ranged 88.1% to 99.3%, average error range 0.14 to 0.28, and average error percentage ranged 1.56% to 6.81% for three different types of liquid fertilizers. In light of these results, it was shown that the developed low-cost pH meter can be useful for practical pH measurement applications.

Growth of the edible crab (Cancer pagurusL.) off south-west England

1974 ◽  
Vol 54 (4) ◽  
pp. 803-823 ◽  
Author(s):  
D. B. Bennett
Keyword(s):  
Egg Production ◽  
Carapace Width ◽  
Large Male ◽  
Annual Growth ◽  
Published Data ◽  
North East ◽  
South West ◽  
Males And Females ◽  
Moulting Cycle ◽  
South West England

Moult increments, annual moult frequency and hence annual growth were determined from suture-tagged edible crabs (Cancer pagurusL.) released and recaptured off Devon, Cornwall, and Dorset.The average moult increments of males and females at a premoult carapace width of 100 mm were similar; at larger sizes the average moult increment of females was considerably less than that of males. Annual moult frequency ofC. pagurusin south-west England decreased with increase in size, females more so than males.As a result of the smaller moult increments and lower moult frequency of females, their annual growth is considerably less than that of males. This appears to be the result of three aspects of sex and reproduction: (1) reduction in moult increments, probably as a result of competition for nutritive resources between egg production and body growth; (2) the interruption of the moulting cycle by successive annual spawnings from a single impregnation at the previous moult; and (3) accentuation of the larger increments in weight at moulting of male crabs due to the allometric growth of their chelae. A consequence of the higher growth rate of males is the presence of very large male crabs – a distinctive feature of the population structure of the stock off south-west England.The growth of C.pagurusin south-west England was compared with published data for stocks off the east and north-east coast. Moult increments were similar for both areas, but there were considerable differences in the moult frequencies. In the south-west, males moult more frequently than females; the opposite is the case for the east and north-east crab stocks. A valid reason for this difference has not yet been established.

The Nearctic species Shipsa rotunda (Claassen, 1923) (Plecoptera: Nemouridae) 

2021 ◽  
Vol 23 (2) ◽  
pp. 50-63
Author(s):  
SCOTT A. GRUBBS ◽  
RICHARD W. BAUMANN
Keyword(s):  
New Records ◽  
Wide Distribution ◽  
Adult Males ◽  
Distribution Map ◽  
Canadian Province ◽  
Us States ◽  
Extensive Range ◽  
The Usa ◽  
Males And Females ◽  
Microscopy Images

The morphological concept of Nearctic Shipsa rotunda (Claassen, 1923) (Plecoptera: Nemouridae) was reviewed based on examination of adult males and adult females from across the extensive range of this species. Reproductive terminalia were studied with scanning electron microscopy from five locations, three from Canada and two from the USA. Despite the wide distribution, there is little morphological variation exhibited by males and females. New records are noted for one Canadian province and six US states. Scanning electronic and standard light microscopy images plus a dot distribution map based on museum and valid literature data are provided. Key words: Plecoptera, Nemouridae, Shipsa rotunda, United States, Canada, stoneflies

Carapace width-weight relationships of blue swimmer crab Portunus armatus (A. Milne-Edwards, 1861) (Crustacea: Brachyura: Portunidae) in southwestern Australia: influences of sex, decadal change, environment, and season

2020 ◽  
Vol 40 (5) ◽  
pp. 526-533
Author(s):  
Danielle J Johnston ◽  
Daniel E Yeoh
Keyword(s):  
Carapace Width ◽  
Sampling Period ◽  
Change Environment ◽  
Southwestern Australia ◽  
Natural Logarithm ◽  
Stock Assessments ◽  
Males And Females ◽  
The Relationship ◽  
Direct Applicability ◽  
Fishery Species

Abstract The relationship between carapace width (CW) and weight (W) of the blue swimmer crab Portunus armatus (A. Milne-Edwards, 1861) was determined for southwestern Australian populations using measurements collected over two decades from a range of nearshore marine and estuarine environments. A strong and significant positive linear relationship occurred between the natural logarithm (ln) of CW and ln(W) for both sexes overall and individually for males and females (R2 = 0.985–0.987; P &lt; 0.001). The relationships were: overall ln(W) = −10.2262 + 3.1708 ln(CW); males ln(W) = −10.4641 + 3.234 ln(CW), and females ln(W) = −10.0595 + 3.1246 ln(CW). Significant differences in the relationship were detected between sexes, decadal sampling periods, environments, and seasons (P &lt; 0.001), with sex and decadal period being most influential. Males were heavier than females at any given CW, which was most apparent at larger (&gt;100 mm CW) sizes. Crabs were also generally heavier at CW in a recent sampling period (2014–2019) than historically (1995–2000), with the greatest decadal differences occurring in the estuarine environment. These relationships have direct applicability for use in stock assessments of this valuable fishery species. Moreover, observed changes in the CW-W relationships over time highlight the importance of regularly reviewing biological parameters used in fisheries assessments, particularly in response to climate change as in the case of southwestern Australia.

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