Dear,
I am using the fluorochrome calcein to mark larval abalone i.e. abalone still in the planktonic (swimming) phase, less than one millimeter in length. I would like to know if anyone has marked larvae (of any sort) this small and what method(s) they used to detect the fluorescence. I am interested in viewing the larvae fluorescence on a macro-scale (with a standard 35 mm camera) and on the micro-scale, using a compound microscope. I do know that the excitation peak for calcein is 490 nm and the emmission peak is 520 nm. If any one has information on filter types, light sources, microscope models, film and objective types I would greatly appreciate a reply.
If you feel your reply should be read by everyone else in the list please respond to:
Otherwise, please reply to me directly on:
In response to : Alan Harvey (italics)
Rotifers are excellent food for very small zoeae, although they are rather more trouble than Artemia nauplii, since you have to keep an active population running, plus you have to keep an active algal culture running concurrently.
COMMENTS 1:
I have successfully raised Daphnia spp. by feeding them fish food (pellets or flakes) put through a blender. This allowed me to raise Daphnia without keeping an algal culture which was a pain. I found that I could blend a bunch of fish food and keep it in the fridge for several days, adding a bit to the Daphnia tanks every day or every few days. This may also work for some rotifers. Though this method seemed a little safer than yeast, which can make a tank foul very quickly. But... these Daphnia tanks were not pretty and did need to be watched for anoxia.
COMMENTS 2:
Speaking of easy ways to raise invertebrates, I have sustained and raised Daphnia pulex (taken from a dystrophic lake) on Chlorella capsules. I found them in our local coop in the vitamin section. They were a little pricey but convenient.
D. Rae Barnhisel, Ph.D.
Molecular Evolution Program
Marine Biological Laboratory
7 MBL Street
Woods Hole, MA 02543
Phone: 508/289-7393
Fax: 508/457-4727
Rotifers are excellent food for very small zoeae, although they are rather more trouble than Artemia nauplii, since you have to keep an active population running, plus you have to keep an active algal culture running concurrently. Isochrysis galbana (or its 'Tahitian' strain, which tolerates higher temperatures) is probably the best rotifer food in terms of zoeal health. If you can't find females with late stage embryos, try feeding the females newly hatched Artemia nauplii. Flake fish food also seems to be very widely acceptable to decapods, but is of course harder on the system than live food. Depending on the species, determining hermit crab ovigery is quick and easy to maddeningly time-consuming. Best technique: hold the shell aperture up and well submerged, holding the shell with forceps if possible (doesn't work with all species), in a darkened room with a light on the crab. If it's a cooperative species, the crab will attempt to right the shell and in doing so extend far enough out of the shell to allow you to see the egg clusters. With some species I've had to put the crabs in a tub, in sand, aperture up, with a piece of one way glass between me and the crab, otherwise they will not expose themselves appropriately.
Assistant Curator of Invertebrates
American Museum of Natural History
Central Park West at 79th Street
New York, NY 10024
(212) 769-5638; fax (212) 769-5783
A former student of mine (Ms. Patricia Aleman-Diaz) reared Pinnotherid crab larvae (adult female less or about 1 cm carapace width) using a 1:1 combination of Monochrysis:Chaetoceros. Dr.G.W. Pohle has used a discrete combination of Tetraselmis-Skeletonema and fertilized eggs of Mellita (Echinodermata: Echinoidea). Depending the relative size of the larvae you may need to supplement with new hatched Artemia nauplii in advanced stages.
Ernesto Campos
Professor of Zoology
Facultad de Ciencias
Universidad Autonoma de Baja California
Apartado Postal 2300, Ensenada,
Baja California 22800 Mexico
U.S. address
Facultad de Ciencias, U.A.B.C.
4492 Camino de la Plaza (Ste.Ese. 1108)
San Ysidro, California 92173-3097
U.S.A.
I am seeking advice from anyone who has experienced problems (fish health) with supersaturation in aquaculture systems. My main question is - at what level is supersaturated water a problem to fish? Recognizing that variability undoubedtly exists among species and perhaps life stages - any input would be appreciated.
My scenario here is frequent outbreaks of "popeye" in raceway systems holding white seabass - a marine sciaenid.
Supersaturation has been speculated as the culprit by some - although I am not convinced. Our present raceway systems are constructed of concrete (40'x10') filled to a depth of 1'. Water is pumped from a coastal lagoon at a depth of 14' and makes one pass through the system. Water flows through biomedia (to help knock gases out) before entering the pool at flow rates of 100-200gpm. We have also observed this problem in certain floating raceways culturing the same.
Using a Sweeney saturometer, we have obtained fairly consistent readings of 102% (+- 0.5). That seems "over-saturated" to me not "super-saturated".
COMMENTS 1:
We have been raising rainbow trout fingerlings at 120-140% O2 saturation for 4 years now with no sign of health problems. As long as the Total Gas Pressure is <110%, (whether due to nitrogen or oxygen saturation) we do not have a problem. We do see some evidence of seasonal popeye, but this is due to a bacterial infection which messes up the fishes ion/osmotic system. The popeye is actually caused by fluid, as opposed to gas.
Doug Aloisi
Neosho NFH
Neosho MO
COMMENTS 2:
I have had some supersaturation problems with marine larvae (seabass and seabream), particularly associated to sudden changes in temperature. We don't have a saturometer, but only a DO meter, and those problems arrive when oxygen is higher then 100% saturation. This problem is very acute and causes hyperinflation of the swimbladder, which causes mortality and the larvae are unable to recover.
I tried to avoid this problem to use a degasification column (biomedia column), as you have, and I got some improvements. Concerning your 102% gas saturation, I don't have comparative readings, however in that case it seems to me that if that value results from N or CO2, you need to care about that.
Maria Teresa Dinis
Maria Teresa Dinis
Universidade do Algarve, UCTRA, 8000 Faro, Portugal
tel. +351 89 800927, fax +351 89 818353 Maria Teresa Dinis
COMMENTS 3:
We have been raising rainbow trout fingerlings at 120-140% O2 saturation for 4 years now with no sign of health problems. As long as the Total gas Pressure is <110%, (whether due to nitrogen or oxygen saturation) we do not have a problem. We do see some evidence of seasonal popeye, but this is due to a bacterial infection which messes up the fishes ion/osmotic system. The popeye is actually caused by fluid, as opposed to gas.
Doug Aloisi
Neosho NFH
Neosho MO
What is the very recent situation with microdiets for marine fish larvae? Two main approaches are obviously followed on in the last few years: a) to replace living feed from the beginning and b) earlier weaning.
Is there anybody dealing with this topic right now and knows more about the situation just at this time?
In our research team we presently use only live and frozen material, but I know that Laval University, (Quebec province, Canada), are working on a project of microencapsulated feed for sturgeon and snow crab. This project was supposed to be initiated last year but has been delayed. IMO opinion, this will not work with snow crab larvae cause the size of the feed and also if I look to their initial report on snow crab raising, they are not going into the right direction. But I cannot tell for sturgeons.
You might try to contact Dr. Delanou at GREREBA (which stands for Groupe de recherche en recyclage biologique et aquaculture) Université Laval
For several years (some time ago) while I was culturing Skeletonema costatum (among others) in Boston water, it would clump and sink to the bottom every spring. I never did figure out what was interfering, presumably metabolites from some other species which was blooming. But once summer started, the Skel began to behave normally. I'm sure that there are algologists that have more information. Virtually every hatchery culturing microalgae as food has periods when one or another species experiences "decreased performance" I have never heard an explanation that would allow a prediction of this type of event, however dinoflagellate blooms have been well studied and there is indication that chemical speciation in the water affected by eg. increased organic load allows a bloom to form. Hope you hear from someone more knowledgable.
Kathy Rhodes.
By: Dale B. Donar
Molluscan hatcheries are well aware of the seasonality problem, as it is usually also reflected in poor growth of molluscan larvae. One way around the problem is to save carboys of water from the "good season" for use with critical cultures during the "poor season". (These can be filtered, UV-treated, etc. and kept dark). This is a reasonable solution for a small hatchery or a research lab when you may only need a few hundred gallons SW, but is generally not going to be much help to a large hatchery needing tens of thousands of gallons.. We used to use stored water at MBL (Woods Hole) for aplysia culture during the "poor seasons". This seasonality was especially noticeable when trying to metamorphose competent larvae. Using water from the "good season" was sometimes the only way to get successful metamorphosis.
There is one heck of a good PhD. thesis here for someone courageous (or foolish?) enough to face the risks.
Dr. Dale B. Bonar
Aquatic Environmental Services
Port Townsend, WA
Burnham, USA
By Youlian
In this case, I think the problem would be minimized if you use aged sea water (>1 year) to prepare your culture medium or treat your fresh seawater by UV light or charcoal for > 1 hour.
By Borgeson
With all due respect, I have found a single pass through a perfectly maintained UV unit to be a highly unreliable means of treating seawater for algae culture. I also see no purpose to aging seawater for 1 year (!) other than to kill competing microorganisms, a job that is done quite well, and quickly, by pasteurization...or autoclaving, as the original poster is
already doing. I think we need to know a bit more about culture conditions before we can give much in the way of advice.
I would like to clarify that the treatment of UV or charcoal for > hour is not just for pasteurization to kill competing microorganisms. The most important is to oxidize a substantialamount of DOC, some of which may be excreted by blooming algae, etc. A single pass through a UV unit is not sufficient!
However, caution should be taken when oxidize DOC in the seawater before use. Some species may need certain organic matter to sustain growth. We have found in our research that UV treated medium promoted growth of certain species but inhibit others. Thus, my suggestion of UV treatment of seawater is not universally useful for algal culture. It may be good for mine, but not necessary good for yours. We have to try for certain species (strains) before give a conclusion.
Youlian Pan
By Borgeson
After poor, inconsistent results with UV, I tried pasteurization at 70 degrees C, and have had routinely good results ever since with some 30 species of algae, diatoms and dinoflagellates. I am not familiar with the need to oxidize DOC. My style is to run 1 micrometer filtered seawater thru a heat exchanger, let it cool, add sterile Guillard f/2 nutrients and vitamins, adjust pH, and inoculate. Perhaps the 70 degree C treatment is doing some carbon oxidation... With N. California seawater treated in this way, I see no seasonality to algae health; somewhat difficult species such as Rhodomonas are thriving, knock wood.
The harvest this year, to date, on the GSL has been slightly ahead of the disastrous 1994/95 harvest season. However, this could have been predicted because the number of permits on the lake increased from 29 to 63 so a lot more effort was expended. The month of December has been very poor harvesting and the cystsare showing signs of breaking and the quality of the Dec. product will certainly be below 75%. The 1994/95 season although poor in quantity was not felt so sharply as the shortage this season will be. This is because in the 94/95 season most harvesters had inventories of lower quality product that had been unmarketable before and with the shortage this product was then saleable and filled a large amount of the product shipped. This year the lower quality cysts are consumed and we cannot expect the harvest to get any better as the majority of the cysts have already been harvested.
Laboratory of Aquaculture & Artemia Reference Center, Ghent University
Rozier 44, B-9000 Gent, Belgium
tel +32-9-2643754; fax +32-9-2644193 (or +32-55-302871)
LARVAL ALERT!! We are interested in getting a regular supply (fora short while) of viable eggs of ANY marine fish capable of taking rotifers or brine shrimp nauplii as first foods, for
studies on factors influencing variability of post-hatchingsurvival. Right now we're using Chromis cyanea and Balistes vetula and having too much trouble getting them through first feeding.
Any and all help, ideas, greatly appreciated.
For the Chromis and Balistes, if anybody has a good culture of marine Euplotes or alternative first food, that would be of interest, too.
Les Kaufman
Boston University Marine Program
Department of Biology
Boston University
5 Cummington Street
Boston, MA 02215, USA
phone: 617-353-5560
fax: 617-353-6340
Daniel Benetti
Crisostomo, David P.
1st line of address
Voice: (671)735-2001~7
Guam Cooperative Extension
Fax : (671)734-6842
University of Guam
Coordinates: 13.5N, 144.7E
UOG Station
Mangilao, Guam USA 96923
'Job posting available'
Technician wanted to assist with research on the development of haddock for aquaculture. Work focuses on the maintenance and feeding of the early life history stages of haddock. Position available for immediate commencement. Salary commensurate with experience. Please forward resume to Paul Henderson/Ganin Downing, UNB-Saint John, P.O. Box 5050, Saint John, N.B., E2J4H6 Canada
tel: (506) 648 5794
Fax: (506) 648 5650
SETTLEMENT AND METAMORPHOSIS OF MARINE INVERTEBRATE LARVAE
an International Symposium
Jointly organised by the Marine Biological Association (UK), JRDC (Japan) and the University of Plymouth, UK, July 15-19, 1996.
5 Themes planned:
Contact: Dr. Tony Clare, Marine Biological Association, Citadel Hill, Plymouth PL1 2PB, UK. Tel: +44 (1752)633100; Fax: +44 (1752)633102; e-mail: T.Clare@pml.ac.uk
Please reply no later than February 19th 1996.
(Department of Fisheries and Oceans, Biological Sciences Branch, Pacific Biological Station, Nanaimo, B.C. V9R 5K, Canada)
(Department of Aquaculture, University of Tasmania, P.O.Box 1214, Launceston, Tasmania, 7250, Australia)
(Department of Zoology and Physiology, Louisiana State University, Baton rouge, LA70803, USA)
(Unite d'Ecologie des Eaux Douces, Facultes Universitaires N.D. de la Paix, 61, rue de Bruxelles, B-5000 Namur, Belgium)
(National Center for Mariculture, Israel Oceanographic and Limnological Research, P.O.Box 1212, Eilat 88112, Israel)
(Laboratory of General Biology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, 54006 Thessaloniki, Greece)
(Caribbean Marine Research Center, 805 East 46th Place, Vero Beach, Fl, USA)
Enclosed is the Scientific Programme for the Workshop; the exact breakdown for the four days (18-21 March 1996) will be sent in the last Circular, in February 1996. We would like to give you here some information about the publication of the Proceedings, preparation of abstracts, room reservations and advance payment to confirm hotel accommodation.
PROCEEDINGS: Both based on our questionnaire and offer from some of the participants, we have decided to publish the Workshop Proceedings in FRESHWATER BIOLOGY as a special issue (instructions enclosed). We hope to get confirmation from Dr. Hildrew, the Chief Editor soon. This tentative information is based on correspondence with Dr. William R. DeMott (member of the Editorial Board of FWB and also a workshop participant) who has also agreed to coordinate the work of the editorial committee).
ABSTRACT: The participants are requested to either send us or bring with them a copy of Abstract and deliver it to us on arrival on 17 March. This will enable us to Xerox it and distribute it the participants before the start of the Workshop on 18 March.
ADVANCE PAYMENT: All the participants are requested to make an advance payment of Dutch Guilders 200.= (net, excluding transfer/ conversion charges) which will be adjusted against your Workshop Registration Fee on arrival (we need this amount to confirm your reservation at the Motel Breukelen. This payment should be made by 15 JANUARY 1996 to ONE of the following two account numbers:
1. Koninklijke Nederlandse Akademie van Wetenschappen, NIOO/Centrum voor Limnologie,
NIEUWERSLUIS, Account No. 42.05.55.374 with ABN-AMRO bank at BREUKELEN
OR
2. Koninklijke Nederlandse Akademie van Wetenschappen, NIOO/Centrum voor Limnologie,
NIEUWERSLUIS, Account No. 66.28.86 with the POSTBANK
in favour of "Plankton Workshop (March 1996)"; please send us a copy of your bank draft/cheque/transfer order by post at the postal address given below:
With our best wishes and Season's Greetings
Ramesh Gulati
Paul Weers
Centre of Limnology
Rijksstraatweg 6
3631 AC Nieuwersluis
The Netherlands
Tel/Lab: (..)31.294.239.300/...350
Fax/Lab: (..)31.294.232.224
e-mail: gulati@cl.nioo.cl OR weers@cl.nioo.cl
Tel/Fax: (..)31.35.624.4407 (Home: Ramesh Gulati)
Address:
Centre of Limnology,
Rijksstraatweg 6
3631 AC Nieuwersluis,
The Netherlands
PROGRAMME:
1. PHYTOPLANKTON
2. EFFECTS OF ENVIRONMENTAL FACTORS ON COMPOSITION
3. ZOOPLANKTON
4. EFFECT OF NUTRIENT LIMITATION OF FOOD ON GROWTH OF ZOOPLANKTON
5. ASPECTS OF FOOD WEB