All About Ikan/Fish (tips bela/ternak & pelbagai spesis)

OJey

IV.  PHYSICAL TOLERANCES

Temperature:
The native habitat of walking catfish is tropical southeast Asia. Intolerance to cold temperature is range limiting (Shafland and Pestrak 1982). Behavioral avoidance of environmental extremes during cold/dry seasons involves burrowing into pond and river banks to enter a dormancy that is interrupted with the arrival of spring rains (Courtenay et al. 1974). Deep water may also serve as a thermal refugium during cold snaps (Courtenay 1970).

Winter thermal kills have been documented in walking catfish from as far south as Florida's Broward County (Courtenay 1970).

Salinity:
C. batrachus is euryhaline across its native range, inhabiting fresh and brackish water as well as muddy marshes (Sen 1985). The species thrives in estuarine waters up to 18 ppt salinity (Courtenay et al. 1970).

Dissolved oxygen:
The common name "walking catfish" comes from this species' impressive ability to "walk" on land, traveling between ponds when a home pond dries up or after a heavy rainfall (Courtenay et al. 1974, Hensley and Courtenay 1980, Liem 1987). They walk on their robust pectoral spines, flexing their body to effect awkward movement on land.

Several physiological adaptations allow the species to leave the water for extended periods. These include a greatly reduced gas bladder and gills that are structurally stiffened to prevent collapse on land. The gills also exhibit highly vascularized arborescent (tree-like) organs that act as accessory breathing structures aiding respiration on land and in stagnant waters.

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V.  COMMUNITY ECOLOGY

Trophic Mode:
Walking catfish are benthic (bottom-dwelling) fish that have have been characterized as voracious opportunistic consumers. Most feeding activity occurs at night and their dietary range includes aquatic insects, insect larvae, small fish, fish eggs and larvae, and occasional plant material (Courtenay 1970, Courtenay et al. 1974). Periods of drought may lead to the aggregation of many individuals within isolated pools where they usually rapidly consume available prey items (Courtenay et al. 1974).

When individuals are dormant within mud burrows they typically survive for several months without feeding (Courtenay 1970).

Associated Species:
Florida native species interactions with walking catfish are typically non-beneficial. C. batrachus will outcompete or directly consume several co-occurring native species.

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VI. INVASION INFORMATION

Invasion History:
Walking catfish are native to southeastern Asia, and the natural range of the species includes Sri Lanka, eastern India, Pakistan, Bangladesh, Burma, Ceylon, Malaya, Singapore, Philippines, Borneo, Java, and Thailand (Axelrod et al. 1971, Jayaram 1981 Sen 1985, Talwar and Jhingran 1991). They were originally imported to the U.S. in the 1960s as an aquarium industry candidate species. Unlike many other accidental introductions to the state of Florida, the release of C. batrachus is partly documented. The initial escape of this species, in the mid-1960s, was either from a Broward County, Florida fish farm or from a truck transporting broodstock. The animals that escaped were derived from stock originally imported from Thailand (Courtenay et al. 1974, Courtenay et al. 1984).

A second, independent introduction in 1967-1968 has been implicated in the establishment of a Hillsborough County C. batrachus population (Courtenay et al. 1974, Courtenay 1978). In this case, animals were reportedly intentionally released by fish farmers after the state banned the possession of walking catfish.

Since these initial release events, walking catfish have rapidly expanded their range within Florida. A combination of traits such as high fecundity, the ability to cross land barriers to move between isolated water bodies, and the ability to avoid desiccation during dry seasons make this fish a capable pioneering invader. The ability of this species to utilize networks of man-made drainage canals has further facilitated its spread in Florida and elsewhere (Nico 2005).

Populations of walking catfish became established in Florida within just a couple years of the initial introduction; by 1968 the species was already established in three counties (Courtenay et al. 1984). Within a decade of initial establishment, the Florida range of walking catfish would expand to nearly 20 counties, and by 1984 the range included all counties within the IRL watershed except Volusia.

Potential to Compete With Natives:
Early on, the invasive potential of C. batrachus was recognized, and Lachner (1970) suggested that the walking catfish Florida introduction was at that time potentially the most harmful introduction to date in the country. That author harvested as much as 3,000 lbs of walking catfish per acre from isolated Florida small ponds.

The walking catfish is a threat to the native fish populations in Florida and the broader Gulf of Mexico region. The Gulf States Marine Fisheries Commission calls it "one of the most notorious and harmful non-indigenous species" in the ecosystem.

The impacts from this opportunist feeder are probably most pronounced in small, isolated wetland ponds where walking catfish quickly consume or outcompete other resident populations to become the dominant species in the pond (Shafland 1996). Resident centrarchids (freshwater sunfish) and native catfish species appear particularly susceptible to impacts from this invader.

Baber and Babbitt (2003) note that C. batrachus can also negatively impact native amphibian populations by preying on tadpoles. The ability of walking catfish to exploit isolated, ephemeral water bodies allows them to access tadpole prey stocks that other fish cannot reach.

Possible Economic Consequences of Invasion:
The actual ecological and economic impact of C. batrachus introduction in Florida is still largely unknown. One specific example of an observed economic impacts is the cost associated with barrier fences. Florida fish farmers have had to install such fences to keep walking catfish out of their ponds (Courtenay and Stauffer 1990, Nico 2005).

Although they are reared as a food crop within much of their native range, particularly in India (Sen, 1985), walking catfish are not at this time valued as a food or sport fish in Florida

The walking catfish has been nominated as among 100 of the "World's Worst Invaders" by the Invasive Species Specialist Group (ISSG).


VII.  REFERENCES

Axelrod H.R., Emmens C.W., Sculthorpe D., Winkler W.V., and N. Pronek. 1971. Exotic Tropical Fishes. TFH Publications, Inc. Jersey City, NJ.

Baber M.J. and K.J Babbitt. 2003. The relative impacts of native and introduced predatory fish on a temporary wetland tadpoles assemblage. Oecologia 136:289-295.

Courtenay, W.R., Jr., Sahlman H.F., Miley W.W., II, and D.J. Herrema. 1974. Exotic fishes in fresh and brackish waters of Florida. Biological Conservation 6:292-302.

Courtenay W.R. Jr. and W.W. Miley, II. 1975. Range expansion and Environmental impress of the introduced walking catfish in the United States. Environmental Coservation 2:145-148.

Courtenay W.R., Jr. 1978. Additional range expansion in Florida of the introduced walking catfish. Environmental Conservation 5:273-275.

Courtenay W.R., Jr., Hensley D.A., Taylor J.N., and J.A. McCann. 1984. Distribution of exotic fishes in the continental United States. Pages 41-77 in Courtenay W.R. , Jr., and J.R. Stauffer, Jr. (eds.). Distribution, biology and management of exotic fishes. Johns Hopkins University Press, Baltimore, MD.

Courtenay W.R., Jr. and J.R. Stauffer, Jr. 1990. The introduced fish problem and the aquarium fish industry. Journal of the World Aquaculture Society 21:145-159.

Courtenay, W.R., Jr., Jennings D.P., and J.D. Williams. 1991. Appendix 2, exotic fishes. Pages 97-107 in Robins C.R., Bailey R.M., Bond C.E., Brokker J.R., Lachner E.A., Lea R.N., and W.B. Scott (eds.). Common and scientific names of fishes from the U.S. and Canada. Special Publication 20, American Fisheries Society, Bethesda, MD.

Deacon J.E. and J.E. Williams. 1984. Annotated list of the fishes of Nevada. Proceedings of the Biological Society of Washington 97:103-118.

Hartel K.E. 1992. Non-native fishes known from Massachusetts freshwaters. Occasional Reports of the Museum of Comparative Zoology, Harvard University, Fish Department. September 1992:1-9.

Hensley D.A. and W.R. Courtenay, Jr. 1980. Clarias batrachus (Linnaeus) Walking Catfish. Page 475 In Lee D.S., Gilbert C.R., Hocutt C.H., Jenkins R.E., McAllister D.E., And J.R. Stauffer, Jr. Atlas Of North American Freshwater Fishes. North Carolina Biological Survey Publication #1980-12. North Carolina State Museum Of Natural History. 854 p.

Jayaram K.C. 1981. The Freshwater Fishes Of India, Pakistan, Bangladesh, Burma, and Sri Lanka- A Handbook. Zoological Survey Of India, Calcutta. 475 p.

Lachner E.A., Robins C.R., and W.R. Courtenay, Jr. 1970. Exotic fishes and other aquatic organisms introduced into North America. Smithsonian Contributions to Zoology 59:1-29.

Page L.M. and B.M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. The Peterson Field Guide Series, volume 42. Houghton Mifflin Company, Boston, MA.

Nico L. 2005. Clarias batrachus Nonindigenous Aquatic Species Database, Gainesville, FL.

Rao G.R.M., Singh S.K. and A.K. Sahu,., 1995. Fry and fingerling production of Clarias batrachus (Linnaeus). Asian J. Zool. Sci. 4:7-10.

Sen T.K. 1985. The Fish Fauna Of Assam And Neighbouring North-eastern States Of India. Records Of The Zoological Survey Of India, Miscellaneous Publication, Occasional Paper No. 64. Calcutta. 217 p.

Shafland P.L. and J.M. Pestrak. 1982. Lower lethal temperatures for fourteen non-native fishes in Florida. Environmental Biology of Fishes 7:139-156.

Shafland P.L. 1996. Exotic Fishes of Florida-1994. Reviews in Fisheries Science 4:101-122.

Talwar P.K. and A.G. Jhingran, (eds.). 1992. Inland fishes of India and adjacent countries. A.A. Balkema, Rotterdam, The Netherlands.

Report by:  J. Masterson, Smithsonian Marine Station

OJey

Accepted scientific name:
Clarias batrachus (Linnaeus, 1758) (accepted name)
        [1 literature reference for Clarias batrachus (Linnaeus, 1758)]

Synonyms:
Clarias assamensis Day, 1877 (synonym)
Clarias betrachus (Linnaeus, 1758) (synonym)
Clarias jagur (Hamilton, 1822) (synonym)
Clarias magur (Hamilton, 1822) (ambiguous synonym)
Clarias punctatus Valenciennes, 1840 (synonym)
Macropteronotus jagur Hamilton, 1822 (synonym)
Macropteronotus magur Hamilton, 1822 (ambiguous synonym)
Silurus batrachus Linnaeus, 1758 (synonym)

Common names:
Thailand catfish English
Thai hito English

Pla duk nam jued Thai
Pla duk dan Thai
Pla duk dam Thai
Pla duk Thai

Philippine catfish English
Pantat Banton, Pangasinan, Tagalog
Paltat Ilokano
Pa douk Laotian
Ngakra Manipuri
Nga-khoo Burmese
Mungri Nepali
Masarai Tamil
Marpoo Telugu
Mangri Hindi
Magur Bengali, English, Marathi, Oriya
Mah-gur Bengali
Mahgur Assamese
Leleh Javanese, Malay
Konnamonni Finnish
Koi Assamese, Bengali, English, Japanese, Kanuri
Kug-ga Punjabi
Klarievyi som Russian
Khamagur Khasi
Keli Malay
Kawatsi Kuyunon
Ito Bolinao, Cebuano, Davawenyo, Hiligaynon, Japanese, Kapampangan, Tagalog
Ikan lele Malay
Ikan ****** Malay
Hitong batukan Tagalog
Hito Bikol, Davawenyo, Kuyunon, Tagalog
Froschwels German
Freshwater catfish English
Climbing perch English
Clarias catfish English
C

OJey

http://www.fao.org/docrep/field/003/AB932E/AB932E00.htm
FEEDS FOR CATFISH (Clarias batrachus Linn.) FRY

1.  INTRODUCTION
2.  METHODS
3.  RESULTS
4.  DISCUSSION
5.  REFERENCES
APPENDIX

FEEDS FOR CATFISH (Clarias batrachus Linn.) FRY1

Samran Dhamrongrat2 and Prasit Kasesunchi3

ABSTRACT

Bioled rice bran, Moina sp., boiled tilapia flesh, fresh chub mackerelviscera and fresh pig blood were tested as feeds for raising fry of pladuk dan (Clarias batrachus).  The fry, averaging 0.233 to 0.316 g, were rearedin pottery water jars containing 5 l of water that was exchanged every twodays.  The feeds were applied at the rate of 5% of the body weight of thefry/day.

At the end of the 65 day trials the best growth gains, ranging from0.51 to 0.82 grams/fish, were attained with the Moina, tilapia and mackerelfeeds.  Average weight gains with the rice bran and pig blood feeds were0.35 and 0.38 grams/fish, respectively.  Survival was relatively high inall cases, ranging from 71 to 92%.  The highest net production in each trialwas with mackerel feed, being the equivalent of 10.6 kg/m3 in trial No.1 and6.5 kg/m3 in trial No.2; the corresponding values for tilapia feed were 8.1and 6.0 kg/m3 while net production on Moina feed in trial No.1 only was9.9 kg/m3.

Reasons to account for differences in growth and production resultsfor the same treatment, between trials, were not evident.
This working paper is a translated version of a report which appears inthe Thai Fisheries Gazette, 18:219

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3.  RESULTS

The differences in results amongst replications of a treatmentwere invariably small.  Consequently, all values for a treatment weredetermined by combining the results of replications and averaging them.Data tables are presented in the Appendix to this report.

Growth curves of the fry fed on the various feeds are illustratedin Figure 1 whereas Table1 summarizes the overall result of the trialsin the presentation of growth and production parameters by treatment.This information indicates that the fry grew best when fed on tilapiamackerel and Moina feeds.  In trial No.1 the average net gain attainedby individual surviving fry over the 65 day rearing time was 0.823,0.713 and 0.617 grams.  Fry fed on rice bran only achieved a weightgain of 0.357 grams.  The growth of fry in trial No.2 was less than intrial No.1 for equivalent treatments; the best weight gains, however,were attained with the tilapia (0.520 g) and mackerel (0.513 g) feedsas opposed to pig blood where the increment was 0.388 grams.

Survival rates were relatively high in all cases ranging from71 to 92% (Table 1).
Of the 7 treatments productivity was highest with Moina feedswhere on day 65 the mass of fish per jar was 72.7 grams (Table A-5)which equates to 14.5 kg/m3.  The next highest was attained withmackerel feed being 65.5 grams (14.2 kg/m3) in trial No.1 and 50 grams(9.9 kg/m3) in trial No.2.  The lowest values were with rice bran(42.5 g = 8.5 kg/m3) and pig blood (43.5 g = 8.6 kg/m3).

4.  DISCUSSION

Boiled tilapia flesh, Moina and fresh chub mackerel visceraappear to be suitable feeds for nursing C. batrachus fry.  Comparativelybetter growth was attained with the use of these feeds thanwith boiled rice bran and fresh pig blood that were also tested inthe experiments.


Figure 1.  Growth curves of C. batrachus fry fed on various testfeeds in two trials, 1961 and 1962, Thailand.

Table 1.  Growth and production parameters of C. batrachus fry reared over 65 days in trials comparing variousfeeds, Thailand 1961 and 1962.

	Trial No.1	Trial No.2
	Feed				Feed
	Rice bran	Moina	Tilapia	Mackerel	Tilapia	Mackerel	Pig blood
No. fish stocked:
total 4 jars	343	352	316	417	276	298	343
per m3	17,150	17,600	15,800	20,850	13,800	14,900	17,150
No. fish, da 65:
total 4 jars	262	323	230	298	232	256	280
per m3	13,100	16,150	11,500	14,900	11,600	12,800	14,000
Survival rate (%)	76.4	81.8	72.8	71.5	84.0	85.9	81.6
Weight fish stocked:
av/fish (g)	0.292	0.284	0.316	0.240	0.290	0.268	0.233
per m3 (g)	5,008	4,998	4,993	5,004	4,002	3,993	3,996
Weight of fish, day 65:
av/survivor (g)	0.649	0.901	1.139	0.953	0.810	0.781	0.621
per m3 (g)	8,502	14,551	13,096	14,200	9,396	9,997	8,694
Weight gain:
av/fish (g)	0.337	0.617	0.823	0.713	0.520	0.513	0.388
per m3 (g)	3,494	9,965	8,106	10,624	6,032	6,566	5,432
per fish/day (g)	0.0055	0.0094	0.0126	0.0109	0.0080	0.0078	0.0060
per m3/day (g)	53.7	153.3	124.7	163.4	92.8	101.0	83.6

The particularly high survival rates of the fry in the trialsmay indicate that the rearing methods were quite satisfactory.  Changingwater every two days could have been a singularly important factor.

Reasons to account for the differences in growth of fry fed ontilapia and mackerel between trials No.1 and No.2 are not clear.  Theymay relate to feed quantities which were not generally determined witha precision that would preclude a large variation, or to environmentalfactors such as differences in temperatures through each trial.  Alternatelythe growth differences may merely be expressions in a normal range ofresults that could be expected from the experimental practices employed.

[ Last edited by  OJey at 20-11-2008 02:54 PM ]

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Size, Age, and Growth

Reproductively mature at one year of age, this species is reported toreach a length of 61cm (24 inches) in its native range, although thelargest individuals in South Florida rarely exceed 36cm (14 inches).Overall, little is known regarding the age and growth of this species.


Walking catfish prey on dragonfly larvae
Albert P. Bekker

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Biology:

    Walking catfish possess a large accessory breathing organ which enables them to breath atmospheric oxygen. They are very well known for their ability to "walk" on land for long distances, especially during or immediately following rainfall (Axelrod et al., 1971; Courtenay et al., 1974; Hensley and Courtenay, 1980; Liem, 1987; Shafland, 1994). This species is found in all types of water, but is more common in turbid, muddy and swampy waters (Courtenay et al., 1974; Hensley and Courtenay, 1980, Talwar and Jhingran, 1991).

    Salinity Tolerance: This species occurs in fresh, brackish as well as marshy, muddy waters over its native range (Sen, 1985). Courtenay et al. (1970), reported walking catfish to occur in intercoastal waterways of up to 18 ppt.

    Temperature Tolerance: The Walking catfish is a tropical species with a moderate tolerance to colder waters. Shafland and Pestrak (1982) reported a lower lethal temperature of 9.8癈, based on which they placed Gainesville as the northern limit to its potential range expansion. During cold dry months, walking catfish burrow into the sides of ponds and streams where they remain dormant until the spring rains initiate (Courtenay et al., 1974). Courtenay (1970) reported winter-kills of walking catfish during January of 1970, when the temperature in northern Broward county dropped to 29癋. However, deeper warm waters served as refuges, allowing many walking catfish to survive the brief cold spell.

    Reproduction and Fecundity: This species engages in mass spawning migrations in late spring and early summer (Courtenay et al., 1974). Inundated patty fields have been reported as favored spawning grounds over its native range (Talwar and Jhingran, 1991). Adhesive eggs are laid in a nest or on submerged vegetation (Hensley and Courtenay, 1980). Males guard the nests(Hensley and Courtenay, 1980). Juveniles 50 mm appear in late summer, and late larval stages as well as early juveniles, have been collected until the first week of November in Broward county, Florida (Courtenay et al., 1974). Sexual maturity is attained at the end of the first year (Talwar and Jhingran, 1991).

    Trophic Interactions: Walking catfish are voracious, opportunistic feeders. They are mainly active at night. Major prey items include attached periphyton for the young, insect larvae, insects such as Haliplus sp., dytiscid beetles, mayflies, and dragonflies, fish larvae, attached fish eggs, fish such as Fundulus, Gambusia, and Lepomis, and occasionally they may take plant material (Courtenay, 1970; Courtenay et al., 1974). Courtenay and Miley (1975) and Courtenay (1978) reported walking catfish to kill large bass, without consuming them afterwards. During periods of drought, large numbers of individuals may congregate into isolated pools, and quickly consume most other species present (Courtenay et al., 1974). This species can remain dormant through periods of drought, and go several months without eating. Courtenay (1970) reported keeping several individuals deprived of food for eight months, without any ill effects observable, except minor weight loss.

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Breeding
As the 'Tropical World' article covers this in much detail we will briefly look at the experiences of Ryedale member Mr. Paul Campion who enjoyed both the thrill and despair of spawning a pair of albino batrachus, on several occasions, during the late 1990s. Paul found that it took a two thirds change of water, with water that had been stood for a day added as a replacement, in order to get his pair of batrachus to spawn.

Pre-spawning was always indicated by the pair's increased appetite and the nudging of each other's genital regions. Eggs were then released during a wrapping movement. The aquarist whose batrachus were the parents of Paul's pair told him that, with a lack of suitable nest building sites, these fish had dug a primitive nest into the gravel, but no nest was ever constructed a generation on as the female just scattered eggs all over the substrate. The male then fertilised these eggs, but although a large number had been shed each time not one egg would ever prove to be fertile.

OJey

Download nice info (pdf file) on "Seed production of Magur using a rural model portable hatchery in Assam"

http://rds.yahoo.com/_ylt=A0oGkm ... oductionOfMagur.pdf

[ Last edited by  OJey at 20-11-2008 05:53 PM ]

OJey

http://www.fao.org/docrep/field/003/AC231E/AC231E03.htm

INDUCED BREEDING AND LARVAL REARING of Clarias macrocephalus

by

Vijai Srisuvantach
Manob Thangtrongpiros
Regional Lead Centre in Thailand
National Inland Fisheries Institute
Bangkhen, Bangkok 10900
Thailand

1. INTRODUCTION

Walking catfish in English, or 損la duk

OJey

7.  Fry Mursing
After yolk resorption, usually within 2 days, the larvae aretransferred from hapa to the nursery fiber glass tank.  The fry developfeeding behaviour at about the same time their yolk was absorbed.  Thefood to be given for the first 3 weeks is live moina.


Usually 3 weeksold fry with the size of 2

OJey

Lecture Notes
Aquaculture Practices, Planing and Extension in Thailand

CONTENTS

1.  Aquaculture and its development plan in Thailand
2.  Some information on aquaculture extension in Thailand
3.  Induced breeding and larval rearing ofClarias macrocephalus
4.  Pla Duk Dan culture in circular concrete ponds with waterrecirculating system
5.  Rearing Larvae of Macrobrachium rosenbergii
6.  Observations on the design construction and Managementof small - scale or backyard hatchery forMacrobrachium rosenbergii in Thailand
7.  Cyst production of artemia salina in salt ponds inThailand
8.  Briefing on sea bass culture
9.  Research and trend of cephalopods culture
10.  Shellfish economics: Course outline for NACAtraining group
11.  Lecture Note Openwater Stocking
12.  Pla salid (Trichogaster pectoralis Regan)a life history and manual for culture

[ Last edited by  OJey at 20-11-2008 06:39 PM ]

OJey

Download word file on Breeding and Culture of Magur (Clarias batrachus)

http://rds.yahoo.com/_ylt=A0oGkm ... echno/7breeding.doc

OJey

More on aquaculture:

http://www.nardf.org.np/website/part%201/chapter3/Chapter3.9.htm

dexa

Ikan Pasifik pakai cermin mata


SUASANA persekitaran yang gelap menyebabkan ikan di dasar laut
menyesuaikannya dengan mata masing-masing.

BERLIN - Saintis Jerman menemui seekor ikan dari Lautan Pasifik yang didapati menggunakan cermin sebagai kanta mata untuk membantu penglihatannya di dasar laut yang amat gelap.

Ikan berwajah seram dan berwarna perang itu sebenarnya sudah pun diketahui sejak lebih 120 tahun lalu tetapi saintis gagal menangkap spesimen hidup untuk kajian ilmiah.

Namun tahun lalu seekor daripadanya berjaya ditangkap di perairan Pulau Tonga oleh sepasukan saintis Universiti Tuebingen dekat sini, menurut pengkajinya kepada jurnal Current Biology.

"Lapisan pertama membentuk kanta ala cermin memfokus cahaya ke dalam matanya dan proses evolusi ini mungkin mengambil masa 500 juta tahun," kata Prof. Julian Partridge. - Agensi

kaki_ayam

actually aku baru join sini...aku join ni sbb aku nk mintak tlg la sket...

cousin aku bg ikan...aku rase ikan ni ikan guppy...

ade la lebih 10 ekor dia bg...2 da padam...

ikan ni makanan dia mcm mana yer? aku bg roti last2 tercekik mampus 2 ekor ikan aku...

aku bg makanan dia yg mcm kepingan kertas tuh...

bg yg bijik tuh dia x mau usik pun...

bg aku tips sket...

kaki_ayam

tolong aku bagi tips pasal ikan emas....

aku x mau ikan aku mati...

cikgutuition

Originally posted by kaki_ayam at 15-1-2009 01:39 PM
actually aku baru join sini...aku join ni sbb aku nk mintak tlg la sket...

cousin aku bg ikan...aku rase ikan ni ikan guppy...

ade la lebih 10 ekor dia bg...2 da padam...

ikan ni maka ...

Kaki_Ayam

Saya pun tgh seronok bela ikan Guppy ni,Mak mertua saya pun bela jugak..Ikan ni ko beri je makanan khas dia yg ada jual di kedai ikan tu..Mak mertua aku lagi sempoi..Bela dalam tong sampah je tapi dalam tu letak pokok yg hidup dalam air tu and the rumput2 yg hidup dalam air pun tumbuh..Air dia x pernah tukar pun..Banyakje ikan tu membiak sebab dia suka ada rumput2 tu untuk lekatkan telur dia...Air pun kalau x silap x leh panas sangat..Maknanya  janganle jemur kat panas tempat ikan korangtu..

Saya pun skrg letakkan kan ikan kat dua tempat..Dalam tong sampah hitam yg besar tu and also aquarium..Ada gak ikan yang betinatu bertelur..Nanti saya updatekan lagi..

Lupa nak add..Mak mertua saya bagi makan makanan ikan yang biji2 tu.Makan lakikan2 tu..Lagi satu dia pesan jangan bagi banyak sangat makanan ikan tu..Sehari sekali je..Kalau byk sgt ikan leh mati n air cepat kotor...

dexa

Ikan 'pontianak' ancam Tasik Besar
Oleh Shamsiah Sanin




Haiwan bermulut bulat dan gigi tajam hisap darah hidupan asal di perairan Amerika

NAMA Tasik Besar Amerika Utara sememangnya tidak asing bagi kita. Namun, secara diam-diam Tasik Besar yang luas ini berdepan kemusnahan teruk akibat kehadiran spesies makhluk perosak yang kecil, dikenali sebagai ikan lamprey atau ikan 'pontianak.'

Ikan menyamai belut, mempunyai mulut bulat dan bergigi tajam ini pula bukannya penghuni asal, sebaliknya berhijrah secara tidak sengaja dari Lautan Atlantik pada abad ke-19.

Caranya memusnahkan spesies lain juga menyeramkan - giginya yang tajam digunakan bagi ‘melekatkan’ dirinya pada ikan lain sebelum mengorek isi dan menghisap darah serta cecair pada mangsanya itu.

Ini menyebabkan ikan itu dalam tempoh beberapa minit akibat kehilangan darah selain jangkitan kuman.

Ancaman dibawa ikan lamprey ini pula bukan kecil sebaliknya menyebabkan kemusnahan yang besar kepada habitat asal di kawasan berkenaan.
Ikan salmon menjadi mangsa Lamprey laut.

Setiap tahun agensi yang bertanggungjawab mengawal pembiakan ikan Lamprey terpaksa membelanjakan lebih AS$20 juta (RM70juta) untuk melaksanakan pelbagai kaedah mengurangkan pembiakannya termasuk menggunakan arus elektrik, pelepasan ikan lamprey jantan mandul dan semburan racun khas.

Pada era 1930 hingga 1940-an kehadiran ikan lamprey secara tidak terkawal mengakibatkan industri perikanan air tawar di Tasik Besar terjejas teruk berikutan kemusnahan ikan asal termasuk ikan tamban air tawar, trout dan ikan putih.

Kepupusan ikan asal Tasik Besar menyebabkan satu lagi spesies ikan tamban dikenali alewife membiak terlalu banyak dan memburukkan lagi kemusnahan ekologi di tasik berkenaan. Ikan ini juga dipercayai menjadi punca utama jumlah beberapa ikan lain terjejas berikutan kandungan bahan kimia thiamine di dalam isinya menyebabkan ikan lain yang memakannya menjadi mandul.

Berikutan itu, ahli sains dan penyelidik tidak jemu menjalankan kajian bagi mencari kaedah terbaik mengawal dan seterusnya menghapuskan ikan lamprey.

Terbaru, penyelidik Amerika berjaya menghasil dan melepaskan sejenis hormon seks tiruan ikan lamprey jantan bagi menarik ikan betina berenang ke hulu sungai dan diperangkap. Kejayaan itu dilaporkan dalam sidang Akademi Sains Kebangsaan baru-baru ini.

Langkah menggunakan hormon tiruan ini dipercayai kali pertama dilaksanakan dalam usaha mengawal haiwan perosak selain serangga.

"Kajian mengenai penggunaan hormon haiwan sedang dilakukan dengan meluas, malah kajian terhadap manusia turut dibuat," kata ketua penyelidik dari Universiti Michigan State di East Lansing, Amerika, Profesor Weiming Li.

Bagaimanapun kata beliau kebanyakan penyelidik menganggap, oleh kerana ciri ikan ini yang kompleks, tabiat mereka juga sukar ditentukan hanya dengan kajian ke atas satu hormon.

Kumpulan penyelidik Profesor Li baru-baru ini melepaskan hormon tiruan lamprey jantan di sebuah anak sungai yang menjadi tempat lamprey membiak.

Lamprey betina yang terbau hormon itu mula berenang ke hulu sungai sehingga bertemu sumbernya dan sebilangannya berjaya diperangkap untuk dimusnahkan.



Pusingan hidup semula jadi ikan lamprey bermula daripada penetasan di sungai dan kehidupan dewasa di laut apabila ia mula menjadi ikan parasit dan bergantung hidup dengan darah dan cecair ikan lain yang dihisapnya sehingga menyebabkan ikan itu mati.

Ikan lamprey betina dan jantan yang kekenyangan akan mencari hulu sungai yang sesuai untuk bertelur dan mati.

Berbeza dengan salmon yang mencari anak sungai asal pembiakannya, lamprey boleh membiak di mana-mana sungai.

“Hormon tiruan ini mungkin boleh digunakan untuk menarik lamprey ke kawasan sungai yang tidak sesuai untuk pembiakan.”

Di habitat asal lamprey di Lautan Atlantik, bilangan haiwan ini dikawal pemangsa semula jadi tetapi di Great Lakes ia tidak mempunyai pemangsa.

Lamprey laut pertama kali muncul pada tahun 1800, selepas pembinaan Terusan Erie yang mengubungkan tasik itu dengan New York selesai.

Lamprey mula membiak dengan tidak terkawal apabila satu lagi terusan yang dibina menyediakan ‘pintu masuk’ kepadanya ke bahagian hujung tasik dan ini menjadi permulaan kemusnahan besar-besaran ikan asal di Great Lakes.

"Apa yang terjadi adalah perkara paling buruk pernah berlaku dalam sejarah penempatan orang Eropah di wilayah ini," kata Dr Marc Gaden dari Suruhanjaya Perikanan Great Laakes (GLFC) badan yang bertanggungjawab menangani maslaah lamprey.

Beliau berkata sebelum 1930-an penduduk bergantung kepada ikan asal seperti trout sebagai punca pendapatan, tetapi menjelang 1940-an lamprey menghuni beribu-ribu anak sungai dan menjejaskan dengan teruk industri menangkap ikan di Great Lakes.

Kebanyakan ikan boleh hidup sama ada di air tawar atau air masin saja, atau seperti ikan salmon berhijrah dari lautan ke sungai, tetapi lamprey mampu membiak ketika ia bergerak dari Atlantik ke kawasan air tawar Tasik Besar.

Setiap seekor ikan lamprey boleh memusnahkan sehingga 20 kilogram ikan trout sepanjang tempoh ia menjadi 'parasit'

"Kami amat teruja dengan penghasilan hormon tiruan ini kerana bagi kami ia satu lagi kaedah menangani masalah ikan lamprey. Ia mungkin boleh digunakan untuk memanipulasi tabiat mereka dan memusnahkannya," katanya.

Profesor Li dan pasukannya kini merancang eksperimen lebih besar iaitu menggunakan hormon untuk memerangkap lamprey betina di 20 anak sungai. Ujian ini dijangka mengambil masa tiga tahun untuk disiapkan.

INFO: Lamprey laut

# Lamprey laut atau nama sainsnya Petromyzon marinus

# Asal dari Lautan Atlantik, boleh ditemui di timur Amerika dan Kanada

# Hanya wujud di kawasan Tasik Besar

# Kali pertama dikesan pada 1936 di Tasik Michigan

# Mempunyai bentuk seakan belut, keluarga ikan tanpa rahang yang sudah wujud sejak zaman dinosaur, panjang antara 20 hingga 40 sentimeter, bahagian belakang berwarna coklat gelap, bermulut bulat dengan gigi tajam, mata besar berwarna merah

# Menjadi ikan parasit apabila dewasa

# Ikan lamprey air tawar ditemui di perairan Washington, sesetengahnya menjadi ikan parasit dan ada yang tidak

# Ikan lamprey air tawar parasit: silver lamprey, chesnut lamprey

# Ikan lamprey air tawar bukan parasit: Spesies northen brook lamprey, American brook lamprey.