A NEW PRINCIPLE OF AQUICULTURE AND TRANSPORTATION OF LIVE FISHES
By A. D. Mead, Ph. D
ESSENTIAL FEATURES AND DEVELOPMENT OF THE METHOD.
The method and apparatus herein described as a novel and practical method
of fish culture have gradually developed through eleven years of continuous
experimentation at the marine station of the Rhode Island Commission of
Inland Fisheries. It may be said, indeed, that the method and the station have
developed together.
The aim has been throughout to provide as simply as possible the essential features of the natural environment, biological and physical, for aquatic animals while kept in confinement, and to introduce as little as possible the unnatural features which are frequently considered necessary in artificial culture.
Upon this principle there has been sought a feasible method of providing water agreeable to the particular species in regard to the various component salts, well aerated but not over aerated, having the proper temperature, density, and current, and containing appropriate food in available condition; while providing at the same time for the elimination of waste products of animal respiration, and avoiding the dangerous chemical and bacterial impurities almost invariably present where the water is passed through systems of piston pumps, closed conduits, and storage tanks, and is aerated by means of forced air.
The first step in the development of the method was a very direct and simple concession, namely, that of going to the ocean instead of trying to bring the ocean into a house on land. The floating laboratory and hatchery was therefore adopted as a feasible method of circumventing, if not surmounting, many difficulties.
During the first and second seasons of work it was clearly demonstrated that the starfish {Asterias jorbesii) could be reared in the course of the summer (four months) from the larval stage to over 50 millimeters measured from mouth to tip of arm (nearly twice the length of sexually mature specimens captured in June, the breeding season, and therefore a year old), in cars of appropriate shape floating in the water between the pontoons of the houseboat.
In this case living food was supplied at first in the form of small barnacles which had set on boards, and later, as the starfishes grew larger, clams, oysters, and mussels were given them to eat. The conditions in these cars were completely adequate for the healthy life of these slow-moving animals, and were abnormal only in that the young starfishes were protected from their enemies (excepting always their cannibal brethren) and were better fed than they often are under natural conditions.
In many cases where they were especially well fed they far outstripped in rapidity of growth individuals found along the shore. They throve splendidly and were perfectly healthy.
This way of raising starfishes may hardly be dignified by the term ” method,” and yet the better condition of these specimens as compared with those usually seen in an aquarium—even in an aquarium where many fishes live for a long time—is a striking fact. It suggests also that there is often something the matter with aquarium water which, whatever the cause, makes it unsuitable for the rearing of very sensitive animals.
At the floating laboratory, animals with the burrowing habit can also be kept confined and protected and under constant observation by simply putting them into a box of sand suspended in the water. Specimens of the soft-shell clam (Mya arenaria) may in this way be very successfully and rapidly reared, and they give every indication of being in a perfectly normal environment.
Indeed, in our experiments, when they were kept just under the surface of the water and in the tidal current, they grew more rapidly than in the most favorable shore locality I have ever seen. In one experiment with clams ranging from 5 to 17 millimeters the increase in bulk during five weeks and two days was 1,861 per cent.
In the case of sessile animals like oysters, Crepidula, Anomia, Molgula, Botryllus, sea anemones, tubiculous worms, etc., and of those which spin a byssus, like the mussel, young clams, and pectens, it is only necessary to provide the proper surface for them to set on and protection from predatory animals.
In case of the hatching of such eggs as those of the flatfish, Menidia, Fundulus, and the lobster, with which we have had experience in the course of our operations, it would seem that the term “hatching” could hardly be used in a transtive sense, for, if the eggs are provided simply with water of proper constitution, temperature, and conditions for respiration, the eggs inevitably hatch themselves.
These nonpelagic eggs, in fact, belong to the same category as the sessile or slow-moving animals and may be treated accordingly. The method of stripping and swirling lobster eggs has been given up with us and instead the ripe-berried hen-lobsters are allowed to crawl about in the rearing cars with the result that the eggs hatch most satisfactorily.
Similarly, the eggs of the flatfish (Pseudopleuronectes) were hatched with almost no loss by placing them on a piece of scrim which formed the bottom of a box about 6 inches deep floated on the top of the water in a protected pool. The eggs of Menidia and Fundulus are hatched successfully by practically the same treatment.
READ MUCH MORE INSIDE… 58 Pages
DOWNLOAD YOUR COPY NOW “A NEW PRINCIPLE OF AQUICULTURE AND TRANSPORTATION OF LIVE FISHES” $9.95
Click on the Red Button Below for Instant Access!
Your name and email will Never be shared, sold, or given to anyone.
We keep our subscriber’s privacy sacred. We do not sell or rent your personal information to other parties. What’s more you can always unsubscribe at any time!
Regards, Coyalita
Copyright © 2021-2024 1-Stop-Sporting-Goods.com All Rights Reserved Privacy Policy – Earnings Disclaimer – Terms of Use – Contact Us
Please note. The ebook is in PDF. file format. You need an Adobe Acrobat Reader to be able to read the ebook. If you do not have Adobe Acrobat Reader installed in your computer, you can download it at http://www.adobe.com. It’s completely FREE.
About Author
