4
VICTOR L. LOOSANOFF A N D HARRY C. DAVIS
Most of the other species, however, were studied less intensively, work
on them being confined to culturing their larvae and observing the
appearance and general behavior of the latter. Naturally, our knowledge
of the requirements of larvae of such species is still fragmentary but,
nevertheless, we shall present the information already available even
though it is admittedly incomplete.
11. EQUIPMENT
The rearing of larval and juvenile bivalves requires an adequate
supply of sea water of proper salinity and free of substances that may
interfere with their normal development. The water used at Milford
Laboratory is pumped from the Wepawaug River at a point about
100 yd from its entrance into Long Island Sound. Because the tidal
rise and fall in this area is from B to 10 ft, the flushing rate of thiR
comparativcly narrow and shdlow inlet i N relatively high.
The sca water is pumped into a 8000-gal wooden storage tank
located in tho laboratory attic. Because pumping normally takes
place 16 hr before and after the high tide stage, the salinity of the
water is usually near 27 parts per thousand, which is virtually the
same as in Long Island Sound, where the majority of the forms, the
larvae of which are described in this article, exists. To assure a supply
of water of high salinity the intake of the salt water system is located
approximately 4 ft below the mean low water mark; therefore, it is at a
safe distance from the surface layers which, after periods of heavy
rains, may be greatly diluted.
The main pump providing the laboratory with salt water is rubberlined. The intake and distribution lines, as well as the check and
cutoff valves, are made of lead. The faucetn, however, are of hard
rubber. The storage tank is of cyj)r(:sH wootl'and irs peiritd innid,? with
asphalt paint.
We prefer lead pipe8 because, although p i p mcufc! of Hnveral new
plastics are nontoxic, light and inaxpennive, they ponrrtnn mvctrel
important disadvantages. One of them ia that n i n w it in oftcrtr rremwnrrry
to reduce fouling inside of tho pipw by trmtjng t h m with hot we&
or steam, t,hiH trontment, Commoniy uned with 1cta.d pipcH, cannot be
employed in HywtarnR contairiing plaHtic parts ae it may c a u ~ e damage,
especially at the joints of the pipeline.
Another serious disadvantage in wing plastics is that they adsorb
and absorb many chemicals, including insecticides, and once contaminated can themselves become a murce of later contamination of
the sea water. Moreover, since somc pla~tics are permeable to inseoticides and other compounds, these materials might enter from the sur-
VICTOR L. LOOSANOFF A N D HARRY C. DAVIS
Most of the other species, however, were studied less intensively, work
on them being confined to culturing their larvae and observing the
appearance and general behavior of the latter. Naturally, our knowledge
of the requirements of larvae of such species is still fragmentary but,
nevertheless, we shall present the information already available even
though it is admittedly incomplete.
11. EQUIPMENT
The rearing of larval and juvenile bivalves requires an adequate
supply of sea water of proper salinity and free of substances that may
interfere with their normal development. The water used at Milford
Laboratory is pumped from the Wepawaug River at a point about
100 yd from its entrance into Long Island Sound. Because the tidal
rise and fall in this area is from B to 10 ft, the flushing rate of thiR
comparativcly narrow and shdlow inlet i N relatively high.
The sca water is pumped into a 8000-gal wooden storage tank
located in tho laboratory attic. Because pumping normally takes
place 16 hr before and after the high tide stage, the salinity of the
water is usually near 27 parts per thousand, which is virtually the
same as in Long Island Sound, where the majority of the forms, the
larvae of which are described in this article, exists. To assure a supply
of water of high salinity the intake of the salt water system is located
approximately 4 ft below the mean low water mark; therefore, it is at a
safe distance from the surface layers which, after periods of heavy
rains, may be greatly diluted.
The main pump providing the laboratory with salt water is rubberlined. The intake and distribution lines, as well as the check and
cutoff valves, are made of lead. The faucetn, however, are of hard
rubber. The storage tank is of cyj)r(:sH wootl'and irs peiritd innid,? with
asphalt paint.
We prefer lead pipe8 because, although p i p mcufc! of Hnveral new
plastics are nontoxic, light and inaxpennive, they ponrrtnn mvctrel
important disadvantages. One of them ia that n i n w it in oftcrtr rremwnrrry
to reduce fouling inside of tho pipw by trmtjng t h m with hot we&
or steam, t,hiH trontment, Commoniy uned with 1cta.d pipcH, cannot be
employed in HywtarnR contairiing plaHtic parts ae it may c a u ~ e damage,
especially at the joints of the pipeline.
Another serious disadvantage in wing plastics is that they adsorb
and absorb many chemicals, including insecticides, and once contaminated can themselves become a murce of later contamination of
the sea water. Moreover, since somc pla~tics are permeable to inseoticides and other compounds, these materials might enter from the sur-