Domestication and Feed Conversion Ratio of Cardisoma Armatum, the Nigerian Land Crab


Scientific Study, 2021

34 Pages, Grade: A


Excerpt

Table of content

CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
1.2 OBJECTIVE

CHAPTER TWO
LITERATURE REVIEW
2.1 DESCRIPTION
2.2 LIFE HISTORY AND POPULATION BIOLOGY
2.3 CONDITIONS REQUIRED FOR CRAB CULTURE INVOLVED THE FOLLOWING
2.4 MUSA SPECIE (BANANA)
2.5 WATER TEMPARATURE
2.6 PHYSICAL TOLERANCE
2.7 BEHAVIOUR CHARACTERS
2.8 REPRODUCTION
2.9 HABITAT DISTRIBUTION
2.10 LOCOMOTION
2.11 SALINITY
2.12 CATCHING METHOD
2.13 STOCK CONTROL NETTING
2.14 HARVEST TECHNIQUES
2.15 POST-HARVEST
2.16 MUSA SPP. (BANANA)
2.17 COMPOSITION OF MUSA SPECIE FOLIAGE (BANANA LEAF)

CHAPTER THREE
MATERIALS AND METHODS
3.1 Experimental site
3.2 Sample Size and Technique
3.3 Experimental animals and Design
3.4 Experimental diet
3.5 Growth Parameter Matrix
3.6 Data Analysis

CHAPTER FOUR
RESULTS AND DISCUSSION
4.1 Data Presentation and Analysis
4.2 MORTALITY RECORDS
4.3 DISCUSSION

CHAPTER FIVE
CONCLUSION AND RECOMMENDATION
5.1 CONCLUSION
5.2. RECOMMENDATION

REFERENCE

CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND OF THE STUDY

Crabs are part of the basic components of the ecosystem and they are consumed as food in many countries. Over 100 species of crabs are known worldwide with nine species common in West African countries especially Nigeria.

Crabs are decapods crustaceans which have a very short tail and are covered with a thick shell, or exoskeleton and are armed with a single pair of claws. There are over 6,793 species of crab spread across the oceans, fresh water, and even on land. Among the species are the land crab (Cardisoma Armatum), the big fisted swim crab (callinectes amnicola), and (callinectes latmanus). These 3 species are edible ones (Abby-kalio 1982, Hart and Chindah, 1998).Crabs mostly occur at the mouth of estuaries and along the course of many main rivers (Oyekanmi 1984). Crabs which are the basic components of the ecosystem are the most advanced members of the phylum Arthropoda.

The freshwater crabs of Nigeria are true crabs which can be distinguished from false crabs by not having 5 pairs of the pereiopods totally or partly concealed beneath the carapace, the antennae were always placed between the inner margin of orbit and fused Pterygostomial region with endotome. True crabs belong to the Suborder Brachyura of order Decapoda under Class Crustacea. It shows the greatest size range of all arthropods such as observed in lobsters, prawns, crayfishes, shrimps, hermit crab and true crabs. (Abby-kalio 1982)

Crabs are widely distributed in the tropical and temperate regions of the world. Literature information is scarce on the food values of most edible crabs in West Africa despite the richness of these gastropods. Most people rate the fish higher in preference to crabs which are considered inferior and food for the low income earners. Over 100 species of crabs are known Worldwide with two species; Sudanonautes africanus and Cardisoma armatum readily known to exist with economic value in West Africa; the mud crabs (Sudanonautes africanus) found in estuaries and mangrove. S. africanus inhabits cracks and holes when fully matured and as small individuals are found under rocks in the littoral zone. (Herklots 1988 and Rathbun.1986­)

Crab constitutes one of the main sources of animal protein most especially among coastal dwellers in some parts of Nigeria. Crabs have a high ash, mineral and crude fiber content, serves as a source of minerals consumed either wholly and partially by sick folks, and is often recommended for pregnant women. Crab fisheries, can be capture or farmed and are found in all of the world’s oceans. There are many aquatic crabs, semi-terrestrial crabs and terrestrial crabs, particularly in tropical regions, due to their nutritional value and abundance scoop of inquisitiveness in nutritional values of crabs are generated in recent times, they are highly exploited but only their fleshes are consumed. Animal protein is very vital in the diet because of the various functions it performs. Fish, beef, pork and poultry products are some of the good sources of animal protein which are used for the growth and repair of body tissues. In developing countries, the high cost of these highly valued animal proteins (i.e. fish, beef, and poultry) has made it impossible for the less privilege to eat them. However, lesser valued animal such as crabs may be used to cater for the protein needs of the less privileged people. Generally, Land crab (Cardisoma Armatum) is sometimes referred to as the rainbow crab in Africa, known as moon crab or patriot crab in Nigeria. According to (Burggren and Mchahon 1988) Land crabs is defined as the crabs that show significant behavior, Morphological, physiological and/or biochemical adaptations per-mitting extended activities out of the water.

However gecarcinid species is a terrestrial crab, as all of them must return to the set for larvae release (cuesta et al. 2002) .The known zoeal of all gecarcinids species are marine planktonic, and complete larvae development consists of five or six stages followed by a megalopa.

Crabs constitute an important species in the traditional prawn or fish culture system in some coastal state and union territories, and have become increasingly popular by virtue of meat, quality and large size.

Cardisoma Armatum belongs to the taxonomy of Dormain: Eucaryota, Kingdom: Animalia, Subkingdom: Metazoa and Eumetazoa, Grade: Bilateral, Branch: Protostomia, Infrakingdom: ecdysozoa, Phylum: Arthropoda, Subphylum: Crustacea, Class: Malacostraca , Superorder: Eucarida, Order: Decapoda, Suborder: Pleocyemata, Infraorder: Reptantia, Section: brachyuran, Superfamily: Grapsoidea, Family: Gecarcinidea, Subfamily: Cardisoma, Species: Cardisoma armatum

Land crab (Cardisoma Armatum) is an omnivore which means it eats both plant and meat. In nature, the crab constitute a nuisance by damaging set of net in water and it diet consist mainly of vegetable and other small insects, reptiles, Amphibians and fish, though crabs also serve as prey to mammals, birds and fishes but they constitute one of the most important members of estuarine food chain. In the current feeding method frozen red worms are used for feeding them. Cardisoma uses it claws to collect and hold the food and direct it toward its head part for eating. Recreational fishermen seek enormous interest in this animal for recreational purposes and Many physiologist have used crabs as experimental animals because it is readily available, economic viable, hardiness and complex life cycle (Smallegange and Vander Meer 2003) Adult are sometimes labeled as soap dish crabs in pet industry. This name derives from aggressive nature as adults and when being ship to pet stores, they are often in soap dishes to prevent them from killing each other. The names moon crab and soapdish crab are sometimes applied to other similar crab species, leading to frequent confusion with other colorful crabs which are the three (3) remaining species of Cardisoma.

These species originates from coastal regions of western Africa, but it also occurs inland along some deltas (e.g. the Volta river delta), and on islands such Cape Verde. When young, these crabs typically have a bluish/violet carapace, red-colored legs, and whitish claws. This colouration usually fades as the crab grows older. They can reach a carapace size of 20cm across, although captive’s individuals rarely reach this size. Their diet often consists of mainly fruit, vegetation and carrion. They are known to be cannibalistic, and will consume smaller crabs, smaller reptiles and amphibians, mollusks, fish and insects if they can catch them while the juvenile and adult crabs spend most of their time on dry land, the females must return to the ocean to release their eggs. The eggs hatch into microscopic larvae, and later on developed they will drown. This is a land crab and cannot remain submerged for long periods. .(Herklots and Rathbun.1986­)

Crabs patterns of distribution are related to salinity, sediment characteristics, temperature, ions and water availability, debit and pH and topography. Associated biotic factors like litters’ floristic diversity, forest complexity and harvesting were identified as the determining factors which affected the distribution and abundance of mangrove crabs.(Herklots and Rathbun.1986­)

There are two major forms of land base cardisoma armatum aquaculture which are fattening of crabs with low flesh /water and grow out of juvenile to market size.

Grow out system can be pond base with or without mangroves, although inter tidal pond can also be used .pond of 0.5-1 acre is suitable for crab culture .The maximum stocking density maybe on crab per square meter .The pond culture period extend from three to six months. The water quality needed to be maintained at salinity of 10-35ppt,temperature of 28-32°c,dissolved oxygen of 5ppm-7ppm,ph 7.8- 8.5,water depth of 0.5-1.0m,however this type of culture is not very popular in some countries like India due to non availability of juvenile/seed crab in sufficient quantity and lack of good quality artificial feed.

Crab fattening is essentially an operation during which post molts or water crabs are kept in captivity for short period of 20-30Days until they flesh out or immature female crab are held until their gonads develop and fill the mantle cavity. This is very popular throughout the Asia countries due to increase demand for gravid female and large size hard shelled crab in sea food restaurant. (Herklots and Rathbun.1986­)

Crab seeds are available in the nature of all sizes. Juvenile crabs can be collected from estuaries, lakes, mangroves and salt water lagoons by using bamboo traps, lift nets and scissor net. Land crab culture depends on mainly on natural feed supply and therefore is a major limiting factor for culture of crabs. (Herklots and Rathbun.1986­)

1.2 OBJECTIVE

The objective of this study is to evaluate the domestication and the growth performance of the land crab (Cardisoma Armatum) cultured in a rectangular concrete unit.

CHAPTER TWO

LITERATURE REVIEW

2.1 DESCRIPTION

Cardisoma Armatum originates in the western coastal of Africa but also occur inland along some deltas and on islands such As Cape Verde. (Anon 2007)

However, most crabs are just as happy to hide. In the wild they would dig burrows. In captivity they're just as likely to scoot under a rock or piece of driftwood. They live at the edge of the water. They survive under water for long periods but need access to land to catch their breath. Like all crabs, they have gills that must be kept moist, so they need access to water at all times. A tank with half water and half land works well. Or you can give them an easy to enter and exit dish of water and mostly land. Cardisoma Armatum was originally shipped in plastic soap dish containers and was thus called "soap dish crabs." They came in yellow, purple, red, and blue. They have a long list of known names in different, like rainbow crabs, moon crabs or patriot crabs, Columbian crabs, and others. Land crabs are scavengers; they eat whatever they find including live plants. (Anon 2007)

When young, these crabs typically have bluish/violet carapace, orange-red coloured legs, light –colored abdomen and whitish claws. The colouration usually fades as the animal grows older and they can reach a carapace size of 20cm across, although captive individuals rarely reach the size. The female’s abdominal apron is wider facial field with mandibles. During mating these crabs so like to do cartwheels while Male crabs have narrow abdomen and their claws are of different sizes (Anon 2007)

2.2 LIFE HISTORY AND POPULATION BIOLOGY

The location and time of copulation is not known but has been observed outside their burrow (Taissoun, 1974). The sperm are carried by the female and fertilization of the eggs is internal (Gifford 1962). Fertilized eggs are carried externally on the abdomen .Egg mass is related to the body weight with 300g females carrying approximately 300,000-700,000 eggs (Gifford, 1962, Feliciano 1962, Taissoun 1974). Females lay their fertilized eggs in salt water along the coast. This occurs with lunar phases (nights preceding and after the full moon). The spawning season varies somewhat with geographic location ; In south Florida it is July- October (Gifford, 1962) on Andros the season frequently ends by September and in Venezuela the season continues until later in the year (Taissoun. 1974). During the early evening there are mass migrations of ovigorous females to lays their eggs in coastal saltwater. Female crab may spawn several times during the season. The eggs immediately hatch into free swimming larvae.

Larvae development proceeds through five zoeal and one megalopa stage (costlow and bookhout, 1968a). On land, crabs dig burrows to the watertable (salt or fresh) and must moisten their gills regularly (Gifford, 1962). Larger crabs tend to move further inland and dig burrows up to a maximum of 2.0m (Feliciano, 1962; Herried and Gifford, 1963).

However, where the terrain is low such as Venezuela (Taissoun, 1974) and Andros, marketable size crabs (over 350g) are commonly found in shallow (less than 2 ft) burrows. There are normally only one crab per burrow and one opening per burrow (Feliciano, 1962; herried and Gifford, 1963; Taissoun 1974).

Crabs deposit their solid wastes at the entrance of their burrows which makes it easy to determine if the burrow is "active”. Juvenile and adult crabs can live with either salt or freshwater (depending on the water table) in the burrows but larvae will develop only in salt water (Gifford, 1962).

2.3 CONDITIONS REQUIRED FOR CRAB CULTURE INVOLVED THE FOLLOWING

2.3.1 THE SOIL QUALITY

The suitable soil suitable for crab fattening is sandy or sandy clay as a sandy bottom discourage burrowing.

2.3.2 THE WATER QUALITY

Abundant of good quality water should be available. Crabs are highly tolerant salinity conditions, so brackish water would be ideal for crab culture operation. The water salinity should be about 15-30ppt and not less than 10ppt,the ph should be around 7.8-8.5,temperature at 28°c-30°c and dissolve oxygen of more than 5ppm.

2.3.3 THE SIZE OF POND AND CONSTRUCTION

Crab culture is practiced in ponds, cages, or pens. Small tidal ponds ranging from 0.025 to 1hac in size with water depth of 0.5-1.0m are generally use for the purpose; a sandy bottom is preferable to discourage burrowing. Bunds should have minimum width of 1.0m at the top to prevent crabs from escaping through the bunds. Crabs are capable of climbing over the bunds, which can be prevented by fixing and hanging fences on the dykes.

2.3.4 WATER SUPPLY AND DRAINAGE

In tidal crab, Water exchange is through tides where sluices gates are used to regulate the inflow and outflow of the tidal water. The sluices gates are fitted to prevent the escape of crabs in region where tidal influence is less. However, in artificial culturing ponds, brackish or seawater or freshwater is pumped in and drained out through outlets.

2.3.5 POND MANAGEMENT

Pond preparation for crab culture is done by draining out the water and allowing it to dry before liming is done. The process will help to get rid of the obnoxious gases and also the pathogen and microbes which are detrimental to the cultured crabs. The water is later pumped in from the reservoir tank to maintain height of above 1.5m. (Baliao, D.D., De Los Santos, M.A. & Franco, N.M. 1999)

2.3.6 STOCKING

Soft shelled crab of 8cm carapace width and above or crabs of more than 550g are stocked and usually the stocking density of 1-3 crabs/m² is usually practiced. Crabs of similar sizes are preferred to reduce cannibalism. Pond can be divided into compartment so that crabs of the same sizes can stored together to avoid cannibalism, Male and female crab can also be stored separately and can be cultured along with fishes like chinos, and mullets which are practiced by farmers in India , however it is not recommended. Monoculture of crabs based on scientific practices yield better result.

The size at which crablets are stocked into mangrove pens depends on the size of the netting used and also if a nursery is installed within the pen. In the case of a pen with a nursery, small crablets of less than 1cm CW can be stocked. Once the crablets are larger than 2cm they can be released into the main pen. The density at stocking that is used should produce 1-1.5tonnes/ha.This figure needs to takes into account typical mortality rates experienced, target production per hectare and the size of crab required at harvest. (Baliao, D.D., De Los Santos, M.A. & Franco, N.M. 1999)

2.3.7 TRANSPORTATION OF CRABLETS

Crablets older than larvae can be transported with or without water. Cooling crablets before transport is recommended to prevent both moulting and lower oxygen consumption during transport. Crablets can also be transported in water using the same method as used for post-larval. (Baliao, D.D., De Los Santos, M.A. & Franco, N.M. 1999)

2.3.8 STOCKING OPERATIONS

Preferably, all stock should arrive at a farm with health checks already completed. Even with a clean bill of health, the quality of crablets (and juvenile stages of other species being stocked for polyculture) must be assessed for quality prior to stocking.

To assess the quality of a batch of crablets one should examine the following criteria:

- Visual health – picks a subsample of crablets and examine for fouling, unusual coloration, damage to legs or claws.
- Size variation – while crablets in any batch may be at different moult stages, size variation should be minimal. Extreme variation in size indicates batches may have been combined. Too large a variation in size increases the likelihood of losses to cannibalism.
- Activity – if crablets have been transported to farm at temperatures less than optimal, they may be sluggish. After equilibrating to ambient temperature, they should be actively walking or swimming shrimp or juvenile fish. Out of water, crablets can be transported in containers on moist sand or damp cloth, in containers that are lined and covered to minimize evaporation and resulting desiccation, while ventilated to ensure they can respire adequately. It is recommended that transport of crablets out of water should not exceed 30 hours. (Baliao, D.D., De Los Santos, M.A. & Franco, N.M. 1999)

2.3.9 FEEDING AND FEEDING METHODS

Cardisoma armatum is an omnivore crabs which means it preys on both plant and meat. In nature, the crab diet consists mainly of vegetables and other lives such as small insects, reptiles, amphibians, fishes and it also feed on small quantities of detritus and plant materials such as banana leaves, onions and some other forage leaves. In current feeding method frozen red worms are used for feeding them. Cardisoma armatum uses its claws to collect and hold the food and direct it toward its head part for eating the food. (Matt Clarke 2005 -11-14).

Feeding rates utilized are often quoted as a percentage of the body weight of crabs in the pond as the quality and nutritive value and other natural feeds varies significantly; these figures are difficult to generalize on. Feeding frequency is typically once or twice a day to minimize the risk of cannibalism, which is considered more likely if the crabs are hungry. (Matt Clarke 2005 -11-14).

However banana leaves {Musa spp. (Musaceae)} is a food crop that generates large amount of forage materials that can be used to feed livestock. Banana leaves which grow continuously from the center of the stem are broad blades,1-4m long x 0.7-1.0m wide, with a pronounced supporting mid rib. Banana leaves and pseudo stem can be fed to animal in flesh, ensiled, or dried form. They are bye product of banana production and are usually available near to the field and processing plants. They can found in all tropical and sub region of Asia, America, Africa and Australia where banana are grown. Banana foliage is a useful source of roughages in many tropical countries .Particularly, it can be used as an emergency feed in case of draught or feed shortage. (Scot C. Nelson et al: 2006).

Banana production yield large quantity of forage biomass, for an average crop fruiting 1.5 times in a year. Forage biomass can amount to 13t/ha/year. Banana leaves contain about 85% of water and 10-17% protein (DM basis). Pseudo stems contains mostly water(92-95%)and very little protein(30-35% DM) fiber content is high, in the 50-70% range for NDF and about 30-45%DM for ADF. They can be fed fresh or sun dried whole or chipped. Pseudo stem are easily ensiled if chipped and mixed with easily with fermentable sources of carbohydrates such as molasses or rice barns. (Scot C. Nelson et al: 2006).

2.4 MUSA SPECIE (BANANA)

Banana is an edible fruit, botanically berry, produced by several kinds of large herbaceous, flowering plants in the genus Musa. In some countries, Bananas used for cooking may be called plantains. The fruit is variable in size, color, and firmness, but is usually elongated and curved with soft flesh richen starch covered with a rind which maybe green, yellow, red, purple, or brown when ripe. The fruits grow in clusters hanging from the top of the plant. Almost all modern edible parthenocarpic (seedless) bananas come from two wild species – Musa acuminata and Musa balbisiana. The scientific names of most cultivated bananas are Musa acuminata, Musa balbisiana, and Musa paradisiacal for the hybrid Musa acuminate and M. balbisiana, depending on their genomic constitution. The old scientific name Musa sapientum is no longer used. Musa species are native to tropical Indomalaya and Australia, and are likely to have been first domesticated in Papua New Guinea. They are grown in at least 107 countries, primarily for their fruit, and to a lesser extent to make fiber, banana wine, and banana beer and as ornamental plants .Worldwide; there is no sharp distinction between "bananas" and" plantains". Especially in the Americas and Europe,"banana" usually refers to soft, sweet, dessert bananas, particularly those of the Cavendish group, which are the main exports from banana-growing countries. (Scot C. Nelson et al: 2006.)

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Details

Title
Domestication and Feed Conversion Ratio of Cardisoma Armatum, the Nigerian Land Crab
College
Lagos State University  (Nigeria)
Course
Fisheries and Aquatic biology
Grade
A
Author
Year
2021
Pages
34
Catalog Number
V985062
ISBN (eBook)
9783346343901
ISBN (Book)
9783346343918
Language
English
Tags
Jolaosho Toheeb
Quote paper
Jolaosho Toheeb (Author), 2021, Domestication and Feed Conversion Ratio of Cardisoma Armatum, the Nigerian Land Crab, Munich, GRIN Verlag, https://www.grin.com/document/985062

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