water density
In order for an object to float on water, how must its density compare to that of water?

a. It must be less than the density of water.
b. It must be the same as the density of water.
c. It must be greater than the density of water.
d. The density of the object doesn’t matter.

Where do you people come from?

water density

Assessment Of Stocking Densities For Optimun Growth Of Fingerlings Of Desi Catfish Clarius Batrachus

ASSESSMENT OF STOCKING DENSITIES FOR OPTIMUN GROWTH OF FINGERLINGS OF DESI CATFISH CLARIUS BATRACHUS

                                                                    P.P.Shelke, R.L.Kale, S.K.Deshmukh

                                                  Krishi Vigyan Kendra, Karda

                                                                        Tq. Risod Distt. Washim (M.S.)

                                     PIN 444506 INDIA

                                                    Email.ID: ppshelke@gmail.com

 

  ABSTRACT

 Experiment was conducted to study the effect of different stocking densities on the water quality, survival and growth of fingerlings of clarias batrachus.  Percent increase in the length was maximum in S1 (20.92%) followed by S2(14.93%) and S3 (10.50%).  The weight (gms) of fish increased from 1.50 to 2.83 in S1, from 1.50 to 2.50 in S2 and 1.50 to 2.08 in S3.  Percent increase in weight was maximum in S1(88.81%)  followed by S2 (66.97%) and S3 (38.81%). It is suggested that  the fingerlings should be stocked in nurseries at the density of about  100-200 per square meter and reared for a further period of 15-20 days.

 Introduction:

 Asian catfish, clarias batrachus is popularly known as desi magur.  The fish is well adopted to live in less oxygenated waters and can live hours together in wet places due to the presence of accessory respiratory organs.  The demand for this fish is owing to its taste and medicinal values.  Fish farmers are unable to take up the culture of species, mainly for want of stocking material and the consumers still depend, to a large extent, on capture sources only.  Hence, research on induced spawning in fingerling raising of this much sought after species is being given importance and technique have been developed for breeding and rearing of Clarias batrachus.  Though the Clarias batrachus have consumer preference, their culture system is yet to be established in Maharashtra. 

 The fish exhibits sexual dimorphism during the breeding season.  Genital papilla in female is button shaped, while in male it is lengthy and pointed.  The fish attains sexual maturity after one year of their age.  Fecundity of the fish is in accordance with the weight and length of the female fish i.e. 50000 – 60000 per Kg body weight of fish.  The magur is usually breaded during June to August   in this region by applying hypophysation technique. 

Materials and Methods:

 Initially the parent material was brought from Central Inland Capture Fisheries Research Institute, Barrackore in West Bengal.  It was transported through Railway in perforated container in AC Cabins.  The parents were kept in Cemented tank of size 15 feet x 6feet x 4 feet.  The tank was encircled by shading net in all the directions and was painted externally by white paint for maintaining the water temperature.  Soil layer was maintained for 8 to 10″  The brooders  were maintained for 3 months till the breeding season.  Regular feeding as per the recommendations of CIFA was done.  Water change was done after every 15 days. water level was maintained for 3 feet.

 Induced breeding was done in the month of June by inducing ova prim hormone.  Fingerlings were developed in indoor hatchery.  These fingerlings were used for the experiment.

 Rectangular ponds of Ferro cement of size  4m x 0.6m x 0.6m was fabricated at KVK campus.  Soil layer was developed at the bottom of depth 0.15 m. Water level was maintained 0.3m. The fingerlings were stocked in three different stocking densities viz  5 per sq.m (S1) , 10 per sq.m (S2) and 15 per sq.m.(S3).  Feeding was done with supplementary diet ( Rice bran-25%, mustard meal -25%, meat meal- 25% and soybean meal 25%.  The feeding was applied on the basis of body weight of fish @ 20% once a day in evening hours.  The experiment was conducted for 105 days. Observation of water temperature was done by Water Thermometer, dissolved oxygen was measured by DO meter, pH was measured by pH meter, salinity was measured by salinity refract meter, conductivity was measured by conductivity meter.  Observations were recorded once in fortnight in morning at 8.00 AM.   

 Results and Discussion:

 Experiment was conducted to study the effect of different stocking densities on the water quality, survival and growth of fingerlings of clarias batrachus.  Following observations were recorded.

 Table: Water quality parameters (Mean + S.E.) and growth of fingerlings of C.batrachus stocked in different densities

Parameters

Stocking Density

S1

S2

S3

Temperature (OC)

18.47a+1.00

18.46a+1.02

18.60a+1.00

DO ( mg/liter)

4.65a+0.23

2.48a+0.21

2.16a+0.35

pH

9.08a+0.17

8.67a+0.13

8.45a+0.16

Salinity, ppt

0.725a+0.03

0.743a+0.03

0.600a+0.03

Conductivity (ppt)

0.862a+0.04

0.895a+0.02

0.907a+0.03

TDS (ppt)

0.430a+0.01

0.450a+0.02

0.455a+0.02

% increase in length

20.92

14.93

10.50

% increase in weight

88.81

66.97

38.81

Conclusions:

 The results of the present study suggested that the survivality decreased within increase in stocking density.  At the density of 5 per square meter the survivavlity was observed to be 100% , it reduced linearly with increase in density to 10 and 15 per square meter.  Therefore it can be concluded that the safest density is 5 per square meter. 

 

 

 

 

About the Author

Does water temperature and/or density affect how much weight scuba divers should use?

Since warm water is denser than colder water and therefore you should float more in warmer water due to density, then should you adjust your weight according to the temperature as you would when switching from fresh water to salt water?

that’s kind of a trick question. differing water temperatures require different exposure suits, which require different weights. diving in the caribbean in a 3mil suit you would use considerably less weights than with your 7mil farmer john in the pacific northwest. so, its really not about the density of the warm versus cold water as much as it is about how much neoprene is between you and that water.

Sure To Grow block water density

Def Leppard English Flag Coolie Cup $9.99 Keep your drink cold while rocking out with this coolie…

Alex Super Baking set – 18 Piece Metal and Plastic Set $12.49 Measure, mix, prep, and bake some imaginary treats| This 18-piece set features a loaf pan, bear pan, heart pan, mixing bowl, rolling pin, whisk, measuring spoons and cup, pastry wheel, 2 star cookie cutters, 2 heart cookie cutter, and an oven mitt. Bon Appetit|…

Set of 2 Heated Stainless Steel Travel Mugs Product Description Keep your favorite beverages hot at all times with this set of 2 stainless heated travel mugs. Plug the detachable cords into any standard 12v car adapter of your car truck or R/V. Durable stainless-steel construction and locking lids ensure a safe trip anywhere. Product Details 12V Heated Travel Mugs – Set of 2 • Capacity: 16 ozs. • Airtight l…

Comforter – Crumble Bear $17.99 This is a soft plush comforter from the Once Upon a Time collection, featuring Crumble Bear. This super soft comforter is perfect to hold on to. Crumble is the feature of this comforter, his head and arms are built into the design. It doubles as a…

Passion of the Christ: Songs (Original Songs Inspired by the Film) $16.99 …

Egyptian Hieroglyphs Made Easy $19.99 Learning and understanding of the ancient Egyptian hieroglyphic language. The hieroglyphic script was the longest lived and earliest form of the Egyptian language. Its use was limited primarily to religious and monumental inscriptions, whereas a more cursive script called hieratic was preferred for administrative and epistolary purposes. Hieroglyphic Egyptian employs pictures of objects, each with…

GE 37771 R40 Heat Lamp, Red, 250-Watt $3.39 250 watt 120 volt R40 Medium Screw (E26) Base Red Heat Lamp Red Incandescent GE Light Bulb…

Scarface – Vinyl Wall Decals Murals Stickers Art Graphic – 44H x29W – by üBer Decals $44.99 Better than wallpaper, wall stickers are a perfect way to decorate your room and express yourself. They are a fun, easy and removable decor solution. These stickers are pre-cut and will only take you several minutes to apply on any surface – walls, doors, windows, and more. Each of our designs come with easy instructions to follow. This is an original design from uBer Decals. All other sellers are…

Coconut Palm Tree – Vinyl Wall Decals Murals Stickers Art Graphic – 72H x 41W – by üBer Decals $64.99 Better than wallpaper, wall stickers are a perfect way to decorate your room and express yourself. They are a fun, easy and removable decor solution. These stickers are pre-cut and will only take you several minutes to apply on any surface – walls, doors, windows, and more. Each of our designs come with easy instructions to follow. This is an original design from uBer Decals. All other sellers are…

Last Night Gus $1.99 …

Google AdWords for The Small Business $16.99 Do you want to create stellar ads that turn into leads and sales? Do you want to minimize the costs of your ad campaigns? Are you spending a lot for a little return? This DVD can help and I believe save you $1,000′s. Do not go it alone; it will cost you in time and money. Learn from this product and get ahead of the pack. Knowing more than your competition is the only thing you need to beat him. …

Charlie Rose – ‘What Just Happened?’ / Religulous (October 13, 2008) $24.95 A conversation about the film ‘What Just Happened?’ with Robert De Niro, Barry Levinson and Art Linson. || A conversation about the film Religulous with Bill Maher and Larry Charles.This product is manufactured on demand using DVD-R recordable media. Amazon.com’s standard return policy will apply….

Gecko Nasal Pad – Large, 4.12 Long $24.95 The Gecko Nasal Pad (formerly the Sleep Comfort Care Pad by Sequal) is intended for patients with Obstructive Sleep Apnea (OSA) who experience pain and discomfort on or around the bridge of their nose associated with using nasal or full face masks. The pad acts as a cushion between the patient’s face and mask, and is simply placed across the bridge of the nose under the mask. The protective polyme…

N.4 High Performance Hair Care – Jour d’automne Mighty Hair Spray – Style Collection 10 oz Aerosol $21.00 A strong, yet flexible hold hair spray that remains in place under high humidity conditions. Keeps hair soft and chic with a no hair spray feeling. Water-free, dry brushable spray gives strong support with no flakes or frizz. Hot tool and root lift values protect hair from heat. Innovative technology provides additional sunscreen properties. Creates long-lasting hair styles and immediate results f…

Kuzy® – AQUA BLUE Keyboard Silicone Cover Skin for Macbook / Macbook Pro 13 15 17 Aluminum Unibody $1.00 Dress up your MacBook Pro in fashionable color, silicone protection now. *** Will Not fit MacBook Air 11″ ***…

Kuzy – GREEN Keyboard Silicone Cover Skin for Macbook / Macbook Pro 13 15 17 Aluminum Unibody $1.00 Dress up your MacBook Pro in fashionable color, silicone protection now. *** Will Not fit MacBook Air 11″ ***…

ASUS (RT-N10+) Wireless-N 150 Entry Home Router: Fast Ethernet and support upto 4 Guest SSID(Open source DDWRT support) $25.98 The ASUS RT-N10+ EZ N Wireless Router can provide four wireless networks which feature dynamic bandwidth allocation and access control. With the ASUS RT-N10+ EZ N Wireless Router, you can allow guests to access the Internet without sharing your password and private network devices by creating a virtual wireless router for guest. Keep the high bandwidth and secure private network for yourself. Purc…

Arm And Hammer Large Drawstring Liners – 29210 – Bci $6.25 Provides natural odor control from baking soda.For pans up to 18.5 x 14.75 x 9.75 .Size12 COUNTColor BCI – 684487…

Arm And Hammer Hooded Pan System – 22118 – Bci $20.04 Compatible with arm and hammer deodorizer dispenser (sold seperately).Carbon/zeolite filter for odor control.Continuous antimicrobial protection.Door included.Easy to clean.Infused with arm and hammer odor neutralizers.SizeJUMBOColor WHITE/TANBCI – 684535…

Cow Ears Case Of 50 Pack of 50 Vanilla Case Of 50 $55.95 Package of 50. Cow Ears Case Of 50 Pack of 50 Vanilla Case Of 50 Best Buy Bones All-natural and healthy pet treat. Baked, making these chews low fat and high in protein. Great alternative to rawhide. Ingredients…

Lilyette Women’s Minimizer Bra #427 $32.00 Experience the elegance of our Lilyette® Simplex Minimizer Bra with Embroidery!Minimizes your bust    Elegant embroidery adds femininityNo wire poke throughFlexible fitFabric ContentCups: 69% Nylon, 31% Lycra® ElastaneEmbroidery: 57% Rayon, 31% Nylon, 12% PolyesterBack: 92% Nylon, 8% Lycra® ElastaneImported…

Maidenform Flexees® Ultimate Slimmer Unlined Minimizer® Body Briefer Your flawless look will be complete with Flexees® Ultimate Slimmer Unlined Minimizer® Body Briefer!      Minimizes and shapes the body Matte and shine fabric and lace accents provides feminine styling  Perfect under all types of clothing      Decreases the bust-line a full size      Provides a flawless look under clothesFabric ContentCups and Front Panel: 78% Nylon, 22% ElastaneB…

Western Chief Boys 2-7 Batman Raincoat Okay seriously? How cool is this Batman raincoat by Western Chief? Your little superhero will wear it rain or shine. In fact, you might just have to pry him out of it at the end of each day. With front snap closure, deep pockets, hood and built-in cape, this coat is sure to be a huge hit! Matching rain boots and umbrella are also available to complete the look. Imported….

Green Toys Sand Play Set $11.00 Kids will ‘dig’ building castles and hunting for buried treasure with the environmentally friendly Sand Play Set from Green ToysTM. Made of recycled plastic, this classic 4-piece collection of tools consists of a bucket, sand castle mold, shovel and rake. Made in the U.S.A from recycled plastic milk containers, which helps save energy, reduces landfill waste, and lowers greenhouse gas emissions, a…

Power Wheels Dune Racer $199.99 The Power Wheels Fisher-Price Stinger XS is a 2 seat, 12v BPRO with large off road tires. This cool dune buggy’s main feature is Monster Traction which delivers superior terrain performance versus other BPROs. * The Power Wheels Fisher-Price Stinger XS is a 2 seat with front storage comparment and seat belts for added play. * Drive two forward speeds 2.5-5 mph and 1 reverse speed 2.5 mph. * Incl…

Alex Toys Draw like A Pro $31.54 A fun and easy way to draw…just turn down the lights, switch on the projector, insert a preprinted slide and trace away| Comes with 124 slides, 6 markers, 10 sheets of paper, and a flip book….

Spark Plugs Pack 10 $1.91 For automotive, motorcycle and marine engines. Unique copper core and exclusive electrode design assures fast starts, peak performance and long life. Chosen by more engine builders and car makers than any other. The source for serious power. . Sold in standard packs only. Package subject to change….

MANIFOLD SET R134a $83.99 Features and Benefits: Anti-flutter gauges smooth out needle movement Yellow hose includes shut-off valve Piston type free-floating valves reduce o-ring wear Extra access port for vacuum line Gauges can be recalibrated to maintain accuracyR-134A Brass Manifold with 3 60″ nylon barrier hoses and standard R-134A Couplers. Coupler sizes 14mm, 15mm, 16mm, 17mm, 18mm and 19mm.  Inner nylon layer …

TOYOTA AVALON 2006-2012 CAR SUV Truck Auto Center Armrest Cover Center Armrest covers protect, renew and add comfort to the center console of your vehicle. This cover fits a 2006-2012 TOYOTA AVALON. Picture shown is of an example of our product on a center armrest. Cover is made from a fleece fabric and is machine washable…

Stride Rite Brady Washable Sandal (Toddler/Little Kid) $44.00 Kids Stride Rite, Brady Closed toe adventure Sandals A great fusion of a sneaker and sandal made to be extra-durable Can be Machine washed and air dried leather and mesh uppers in a breathable but still protective sandal style Antimicrobial treated fabric linings to wick away moisture and prevent odors Dual adjustable straps – one at the instep and the other at heel for a personalized and sec…