Different Feeding on Survival and Growth Performance of Mud Crab (Scylla sp.)

Introduction

I am a graduate of Faculty of Fisheries majoring in Aquaculture from Brawijaya University, I took this topic as the title of my final task. In my opinion, the mud crab commodity still very rare to be discussed. Fishery commodities that are widely discussed are Vannamei Shrimp, Tilapia, Grouper, Windu Shrimp. Crustacean species such as lobster and crab are rarely discussed, even though the existence of crabs and their role in the export of fishery commodities is quite large, especially in Indonesia.

The potential of fishery resources that can be developed in the mangrove area is the mud crab commodity. The amount of market demand for mud crab commodities from time to time shows an increase. This is evidenced by the large export volume of Indonesian crabs which reached 29,038 tons with an export value of US$ 321,842. In 2016 - 2017, from January to November there was an increase in the export value of crabs and small crabs by 29.46% (BPS, 2018). Data from the Director General of Fisheries and Aquaculture (2017) also states that the export value of crabs and small crabs in 2012 – 2017 grew by 6.06%. Market opportunities for mud crab commodities are open, both domestic and international markets. The demand for mud crab is more than 450 tons every month (Tiurlan et al., 2019).

The high demand for mud crabs is not accompanied by sustainable culture. So far, the mud crabs produced still rely on the capture-fishing sector (69%) and the rest from the culture sector. If this trend continues, it is feared that there will be extinction of mud crabs in nature, therefore it is necessary for mud crab culture to be sustainable.

Talking about aquaculture, there are 3 important components that must be present. The three components are the type of commodity being cultured, the environment in which the commodity is cultured and the nutrition or feed provided for the commodity. So far, mud crabs still rely on natural food types such as benthos, small fish and small shrimp that grow in their habitat, there needs to be research related to artificial feeding on the survival and growth of mud crabs in order to find out the best type of feed that can be given to mud crabs.

Nutritional Needed

Mud crabs have nutritional needs such as protein, fat, carbohydrates and cholesterol. The estimated protein requirement for mud crab is 37% and the fat requirement is around 5.3 to 13.8%. Cholesterol requirements for mud crabs are in the range of 0.51%. The carbohydrate needs of mud crabs are in the range of 3.51 – 4.20 kcal/g. In the manufacture of artificial feed, fat is needed as much as 7-18%, protein as much as 43-58% for maturation and the breeding process (Ali, 2019).

The nutritional needs of crabs include protein, carbohydrates, fat, vitamins and minerals. In addition to nutrient levels, the balance of protein and energy in the feed also needs to be considered. Protein for crab feed should come from animal protein. This is because animal protein is easier to digest with amino acid content which tends to be more complete than vegetable protein. Vegetable protein is difficult to digest because it is encased in cellulose walls and lacks sulfur-containing amino acids. However, plant materials are still needed by crabs as a source of carbohydrates and as a source of vitamins by mud crabs (Fujaya et al., 2019).

Larval nutrition studies have benefited from the development of a particulate larval diet. Live feeds are nutritionally incomplete and routinely fortified with algae or commercial booster formulations. Mud crabs require feed with a crude protein content of 32 – 40% and crude fat as much as 6 – 12%. Mud crabs also need certain nutrients such as cholesterol (Paterson dan Mann, 2011)

Parameter Used

The parameters used to determine the effect of the type of feed on the survival and growth of mud crabs were survival rate (SR), feed conversion ratio (FCR) and specific growth rate (SGR). The types of crab used were Green Mud Crab (S. Paramamosain), Orange Mud Crab (S. olivacea) and Large Mud Crab (S. serrata). The stadia used for the comparison of results were from Zoea to Adult Crab.

Results
1.1 Survival Rate (SR)

A. Scylla paramamosain

Live shrimp feed and a mixture of live shrimp with minced shrimp gave the highest SR value to the mud crab S. paramamosain. This is because the mud crabs that have reached the megalopa phase require adequate nutrition to meet their survival. The megalopa phase in mud crabs begins to have a direct response to food search (Supadminingsih et al., 2018). The feed in the form of live shrimp and a mixture of live shrimp with minced shrimp meat contains nutrients that meet the nutritional needs of mangrove crabs and has an attractiveness in the form of the attractive properties of live shrimp and an attractive aroma (Ong et al., 2020). This is in accordance with the eating habits of mud crabs which seek prey based on scent and are attracted to attractive prey. Rotifera and artemia feed gave the lowest SR value. This is because the nutritional needs of mud crabs are not met and the movement of rotifers and artemia is not attractive to mud crabs. The aroma produced by rotifers and artemia also does not attract mud crabs to eat them (Quy et al., 2017)

B. Scylla serrata

Chicken intestine feed, trash fish, and a mixture of commercial feed with spinach flour had the highest SR values ​​for S. serrata mud crabs. This is because the rearing environment is controlled, the water quality is sufficiently considered, the mud crabs are also given time to adapt to the new environment, the amount of feed is sufficient and there is no food competition that triggers cannibalism (Akbar et al., 2016). In addition, the commercial feed provided contains nutrients such as protein, fat, carbohydrates, vitamins that meet the needs of mangrove crabs to survive and the presence of ecdysteroid hormones from spinach to support the moulting process and self-defense agents from insect or worm attacks (Edi et al., 2020). The body size of the mud crab used as a test animal also affects the high SR value, the body size of the test crab is 100 grams which indicates the crab is large enough to survive (Edi et al., 2020). Mangrove snail (Telescopium sp.) feed has the lowest SR value because mud crabs must adapt to an environment that is not in accordance with their natural environment. The existence of competition with micro-organisms that enter through the gaps in the container, competition with other crabs can trigger cannibalism (Sihite et al., 2020). The culture system carried out is by confinement of rectangular wering placed in a row (Akbar et al., 2016) and a recirculation system in the form of a three-story box and 4 rows per level (Edi et al., 2020) while for Sihite et al. (2020), the mud crab culture container was not stated exactly, there were only 12 containers with 4 treatments and 3 replications and 1 aquarium as a place for mud crab acclimatization and adaptation.

C. Scylla olivacea

Chicken intestine feed and apple snail meat produced the highest SR for S. olivacea mud crabs. This is because the mature S. olivacea has met its nutritional needs to survive. There is no competition for food and good water quality management also causes the SR value to be high (Das et al., 2020). Artemia and rotifer feeds did not give good results for the survival of mud crabs. Protein needs have actually met the nutritional needs of mud crabs, but there needs to be an enrichment of essential amino acids that are useful for increasing the survival and growth of mangrove crabs. Natural feed enriched with essential amino acids such as histidine for rotifers, leucine and tryptophan for artemia can increase the productivity of mud crabs (Waiho et al., 2018). Artemia contains 57.70% protein, 1.62% ash, 2.22% fat, 0.00% crude fiber and 38.46% Nitrogen-Free Extract (Hadiroseyani and Sutanti, 2013). The nutritional content of rotifers is 15.9 – 22.7% carbohydrates, 21.4 – 24.12% fat, 45.7 – 61.3% protein and 4.5 – 4.6% ash (Sucipto, 2020). Artemia and Rotifera do not have other ingredients needed by mud crabs such as cholesterol, fish oil, vitamins and fiber.

Based on the SR values ​​obtained from these tables, several conclusions were obtained. The mud crabs of S. paramamosain are generally in the juvenile phase, the mud crabs of S. serrata are in the immature phase and the mud crabs of S. olivacea are in the juvenile phase and some are in the immature phase. The difference in the type of feed given to the results of SR is more or less influenced by the species, phase and body size of the mud crab. Mud crabs in the juvenile phase tend to like natural animal feed to support their survival, while mud crabs in the immature phase still require natural feed although it can be combined with artificial feed to support their survival. This is in accordance with the statement of Mulqan et al. (2017) that fish survival can be influenced by several factors. These factors are divided into two, namely internal factors and external factors. Internal factors can consist of the age of the fish and the health condition of the fish. External factors can consist of water quality, feed and environment.

1.2 Feed Convertion Ratio (FCR)

A. Scylla paramamosain

Fish meal 50% gave a highest FCR value in mud crabs of S. paramamosain species. This is because the percentage of protein from fish meal given is not efficient enough for mud crabs. As a result of this, feeding is more frequent to fulfill protein from the nutrients needed by mud crabs so that the FCR produced is quite large (Kader et al., 2017). Fish meal feed and 9% fix oils gave the lowest FCR values. This is because the percentage of protein from fish meal, fat and cholesterol from fix oils fulfills the nutritional needs of mangrove crabs. 9% fix oils contain crude protein, crude fat, BETN and ash, respectively; 46.08%, 11.63%, 24.00% and 11.76%. The amount of protein and fat content of 9% fix oils is sufficient for the nutritional needs of mud crabs (Zhao et al., 2015).

B. Scylla serrata

The trash fish feed gave the highest FCR value to the mud crab S. serrata. This is because the protein content of trash fish is not sufficient to meet the protein needs of mud crabs because it fluctuates. This causes mud crabs to require trash fish as feed in sufficient quantities to meet their protein needs and this causes the FCR to be high (Dyal et al., 2019). The trash fish feed added with crude fish oil (CFO) as much as 6.00% had a low FCR value. CFO complements unstable trash fish protein and nourishes mud crab with fat and cholesterol so that the resulting FCR is quite low. CFO contains 3.622% EPA and 3,556 DHA. The addition of essential fatty acids can streamline the body’s energy utilization so that it becomes more optimal for growth (Hudita et al., 2016).

C. Scylla olivacea

Tilapia feed provided the highest FCR value for mud crabs of S. olivacea species. This is because the protein content in tilapia (O. niloticus) does not meet the nutritional needs of mud crabs when consumed in small quantities. The FCR is high because it takes a lot of tilapia meat to meet nutrient absorption in mud crabs (Das et al., 2020). Artificial feed as much as 20% of the tested mud crab body mass resulted in a low FCR value. This is because artificial feed contains more complete nutrients than tilapia. The artificial feed contains protein, fat, carbohydrates, minerals, and vitamins needed by mangrove crabs so that the nutrients produced are well absorbed by mud crabs. Artificial feed with 20% of crab body mass contains 46.9% crude protein, 9.1% fat, 2.3% crude fiber, 10.9% ash, 30.8% BETN and 18 gross energy. 9 MJ/kg. (Usman et al., 2016).

Based on the FCR values ​​obtained from these tables, several conclusions were obtained. Mud crab species S. paramamosain, S. serrata and S. olivacea had the same trend of FCR results for natural and artificial feeds. Natural feeding has a higher FCR yield compared to artificial feed for mud crabs. This can be affected by nutrients from artificial feeds and additional supplements better meet the nutritional needs of mud crabs.

1.3 Specific Growth Rate (SGR)

A. Scylla paramamosain

The feed with the addition of phospholipid level 2 and cholesterol as much as 1.11 had the highest SGR value for the mud crab type S. paramamosain. This is because crustaceans have a high enough need for phospholipids. Appropriate levels of phospholipids promote growth in some aquatic organisms (Xu et al., 2019). Giving cholesterol is also able to increase weight gain and can increase the metamorphosis of crabs from megalopa to juvenile. The cholesterol requirements of crustaceans are quite diverse because they are influenced by differences in species, levels of life and cultivation conditions (Zheng et al., 2018). The growth of mud crabs in the juvenile stage is faster and shows that the nutrients used have met the maintenance needs so that the remaining nutrients are used to grow. The feed in the form of 7% fat and 0.60% DHA/EPA had the lowest SGR value. This is because the absorption of nutrients obtained from 7% fat and 0.60% DHA/EPA is not optimal. Fat is a source of energy and DHA/EPA is an essential fatty acid for optimal growth of mud crab (Wang et al., 2021). However, the levels of fat and essential fatty acids need to be considered considering that mud crabs require about 13.8% of their body fat (Fujaya et al., 2019). If the fat produced is too little or too much, it causes the growth of mud crab to be not optimal.

B. Scylla serrata

The feed in the form of mangrove snails (Telescopium sp.) with a frequency of feeding 4 times a day has the highest SGR value in mangrove crabs of the type S. serrata. This is due to the large frequency of feeding given to mud crabs. The frequency of 4 times a day is sufficient to meet the maintenance needs of mud crabs to survive so that the remaining nutrients can be channeled for growth needs (Sihite et al., 2020). The feed in the form of a mixture of commercial feed and spinach flour (Amaranthus sp.) had the lowest SGR value. This is because the feed eaten is underutilized, besides the length of feed in the water also causes the nutritional content of the feed to decrease. The eating habit of mud crabs which prefer to tear food also causes food to be wasted when torn (Edi et al., 2020).

C. Scylla olivacea

Artificial feed as much as 40% of the tested mangrove crab body mass had the highest SGR value for S. olivacea mud crabs. This is because the absorption of nutrients obtained from artificial feed is quite optimal and meets the nutritional needs of mud crabs to grow (Usman et al., 2016). The feed in the form of mulberry leaf powder had the lowest SGR value. This is because the artificial feed given has not been used optimally. The nature of the mud crabs which tear their food apart causes the feed given to be destroyed. The conditions of the cultured environment also cause the appetite of mud crabs to decrease, while the need for nutrients for metabolic processes increases, given the existence of self-defense from extreme environments (Kamaruddin et al., 2018).

Based on the SGR values ​​obtained from these tables, several conclusions were obtained. The different species of mud crabs, life phase, body size and density have an influence on the SGR value produced. Artificial feed with vegetable ingredients tends to have a low SGR value for mud crabs. This can be because mangrove crabs still need natural animal ingredients in accordance with the habits of eating mangrove crabs by tearing food. Another influence is the aroma of natural animal ingredients that captivate the sense of smell and appetite of the mud crab.

Conclusions

Types of feed that can be given to mud crabs (Scylla sp.) are natural foods such as trash fish, minced shrimp and rebon shrimp. Types of artificial feed can also be given such as fix oils, cholesterol, EPA and DHA mixed with fish meal. Mud crabs have nutritional needs in the form of protein, cholesterol and fat. Different feeding does not have an effect on the specific growth rate of mangrove crabs but has an effect on the feed conversion ratio. The best type of feed for mud crab today is natural food such as rebon shrimp and minced shrimp, this is because natural feed provides the highest survival rate with a fairly stable growth rate even though the feed conversion ratio is quite high.

References

Agustini, T. W., Y. S. Darmanto., I. Wijayanti., dan P. H. Riyadi. (2016). Pengaruh perbedaan konsentrasi daging terhadap tekstur, nutrisi dan sensori tahu bakso ikan nila. Jurnal Pengolahan Hasil Perikanan Indonesia, 19(3), 214–221.

Akbar, W., Yusnaini, dan W. H. Muskita. (2016). Pertumbuhan kepiting bakau (Scylla serrata) yang diberi pakan usus ayam yang dikukus dan ikan rucah. Media Akuatika.

Ali, S. A. (2019). Nutritional Feeding of Fish and Shrimps in India. MJP Publisher.

Badan Pusat Statistik. (2018).bps.go.id

Budi, S., M. Y. Karim, D. D. Trijuno, M. N. Nessa, dan H. Herlinah. (2018). Pengaruh hormon ecdyson terhadap sintasan dan periode moulting pada larva kepiting bakau Scylla olivacea. Jurnal Riset Akuakultur, 12(4), 335–339.

Das, K. P., S. Mondal, and A. Asif. (2020). Growth and economic performance of different supplementary feed on female mud crab (Scylla olivacea) fattening in plastic box. Asian Journal of Medical and Biological Research. https://doi.org/10.3329/ajmbr.v5i4.45269

Dayal, J. S., C. P. Balasubramanian, K. Ambasankar, R. Jannathulla, and E. A. Claret. (2019). Effect of dietary protein level on fattening and mineral profiles of mud crab, Scylla serrata, in individual cages under mangrove ecosystem. Aquaculture Research. https://doi.org/10.1111/are.14094

Djunaedi, A. (2016). Pertumbuhan dan prosentase molting pada kepiting bakau (Scylla serrata Forsskäl, 1775) dengan pemberian stimulasi molting berbeda. Jurnal Kelautan Tropis, 19(1), 29–36.

Edi, E., W. H. Muskita, O. Astuti, A. Kurnia, M. Hamzah, dan Y. Yusnaini. (2020). Pengaruh penambahan tepung daun bayam dalam pakan komersil terhadap pertumbuhan kepiting bakau (Scylla serrata) yang dipelihara dengan sistem resirkulasi tertutup. Jurnal Media Akuatika, 5(1).

Fujaya, Y., S. Aslamyah, L. Fudjaja, dan N. Alam. (2019). Budidaya dan bisnis kepiting lunak: stimulasi molting dengan ekstrak bayam. Firstbox Media.

Gong, Y. Y., J. X. Lu, X. S. Wang, and Y. Q. Huang. (2017). Response of hatchery-culturedmud crab (Scylla paramamosain) instarfed natural prey and an artificial feed. Israeli Journal of Aquaculture - Bamidgeh.

Hadiroseyani, Y., and A. Sutanti. (2013). Growth of tiger shrimp Penaeus monodon post-larvae fed on Artemia containing Vibrio SKT-b probiotic. Jurnal Akuakultur Indonesia, 12(1), 79–85.

Hudita, K. (2016). Penambahan crude fish oil (CFO) pada pakan terhadap pertumbuhan dan rasio konversi pakan pada kepiting bakau (Scylla serrata). Universitas Airlangga.

Islam, M. L., M. S. Islam, K. Yahya, and R. Hashim. (2017). Effects of essential fatty acids containing natural and commercial diets on larvae rearing of the green mud crab Scylla paramamosain (Estampador 1949). Journal of Scientific Research. https://doi.org/10.3329/jsr.v1i1.28805

Jesson, J., L. Matheson, and F. M. Lacey. (2011). Doing your literature review: Traditional and systematic techniques. Sage.

Kader, M. A., M. Bulbul, M. Asaduzzaman, A. B. Abol-Munafi, N. M. Noordin, M. Ikhwanuddin, M. A. Ambak, M. A. Ghaffar, and M. E. Ali. (2017). Effect of phospholipid supplements to fishmeal replacements on growth performance, feed utilization and fatty acid composition of mud crab, Scylla paramamosain (Estampador 1949). Journal of Sustainability Science and Management.

Kamaruddin, K., U. Usman, dan A. Laining. (2018). Penggunaan tepung daun murbei (Morus alba l) dalam pakan pembesaran kepiting bakau, Scylla olivacea. Jurnal Riset Akuakultur. https://doi.org/10.15578/jra.12.4.2017.351-359

Kar, S., M. A. Salam, and K. S. Rana. (2017). Artificial feed development through fishmeal replacement with non-conventional feed stuff for mud crab (Scylla serrata) fattening. Indian Journal of Applied Research, 3(6), 237–242.

Mulqan, M., E. Rahimi, S. Afdhal, dan I. Dewiyanti. (2017). Pertumbuhan dan kelangsungan hidup benih ikan nila gesit (Oreochromis niloticus) pada sistem akuaponik dengan jenis tanaman yang berbeda. Syiah Kuala University.

Ong, Q. M., R. Fotedar, and T. T. T. Ho. (2020). Selection of locally available diets for rearing Scylla paramamosain megalopa to first crablet stage. Aquaculture. https://doi.org/10.1016/j.aquaculture.2020.735319

Quy, O. M., R. Fotedar, and H. T. T. Thy. (2017). Extension of rotifer (Brachionus plicatilis) inclusions in the larval diets of mud crab, Scylla paramamosain (Estampodor, 1949): Effects on survival, growth, metamorphosis and development time. Modern Applied Science. https://doi.org/10.5539/mas.v12n1p65

Sihite, F. S., C. Mulyani, dan A. Putriningtias. (2020). Optimalisasi frekuensi pemberian pakan keong bakau (Telescopium telescopium) terhadap pertumbuhan kepiting bakau (Scylla serrata). Jurnal Ilmiah Samudra Akuatika. https://doi.org/10.33059/jisa.v4i1.2447

Sucipto, A. (2020). Teknologi Bioflok dalam Budidaya Ikan Nila. Adi Sucipto. https://books.google.co.id/books?id=kmroDwAAQBAJ

Supadminingsih, F. N., A. D. P. Fitri, dan A. Asriyanto. (2018). Pola gerakan stadia umur kepiting bakau (Scylla serrata) dalam merespon makanan yang berbeda (skala laboratorium) the model movement of mud crab’s life stage (Scylla serrata) in responds to different food (laboratory scale). Saintek Perikanan: Indonesian Journal of Fisheries Science and Technology, 12(1), 1–6.

Suryani, N. D. P. I., P. G. S. Julyantoro, dan A. P. W. K. Dewi. (2017). Panjang karapas dan laju pertumbuhan spesifik kepiting bakau (Scylla serrata) yang diberi jenis pakan berbeda di Area Ekowisata Kampung Kepiting, Bali. Journal of Marine and Aquatic Sciences. https://doi.org/10.24843/jmas.2018.v4.i01.38-46

Usman, U., K .Kamaruddin, dan A. Laining. (2016). Performa pertumbuhan krablet kepiting bakau (Scylla olivacea) dengan frekuensi pemberian pakan berbeda pada stadia pendederan. Jurnal Riset Akuakultur. https://doi.org/10.15578/jra.11.2.2016.163-170

Waiho, K., H. Fazhan, E. T. Quinitio, J. C. Baylon, Y. Fujaya, G. Azmie, Q. Wu, X. Shi, M. Ikhwanuddin, and H. Ma. (2018). Larval rearing of mud crab (Scylla): what lies ahead. Aquaculture, 493, 37–50.

Wang, X., M. Jin, X. Cheng, X. Hu, M. Zhao, Y. Yuan, P. Sun, L. Jiao, M. B. Betancor, D. R. Tocher, and Q. Zhou. (2021). Dietary DHA/EPA ratio affects growth, tissue fatty acid profiles and expression of genes involved in lipid metabolism in mud crab Scylla paramamosain supplied with appropriate n-3 LC-PUFA at two lipid levels. Aquaculture. https://doi.org/10.1016/j.aquaculture.2020.736028

Xu, H., J. Wang, T. Han, X. Li, P. Zheng, F. Yin, and C. Wang. (2019). Effects of dietary phospholipids levels on growth performance, lipid metabolism, and antioxidant capacity of the early juvenile green mud crab, Scylla paramamosain (Estampador). Aquaculture Research. https://doi.org/10.1111/are.13922

Zhao, J., X. Wen, S. Li, D. Zhu, and Y. Li. (2015). Effects of dietary lipid levels on growth, feed utilization, body composition and antioxidants of juvenile mud crab Scylla paramamosain (Estampador). Aquaculture. https://doi.org/10.1016/j.aquaculture.2014.09.018

Zheng, P., J. Wang, T. Han, M. Yang, X. Li, and C. Wang. (2018). Effect of dietary cholesterol levels on growth performance, body composition and gene expression of juvenile mud crab Scylla paramamosain. Aquaculture Research. https://doi.org/10.1111/are.13807