Date: 21 Aug 1997
From: Eric Arthur B Routledg <routledg@cca-gw.cca.ufsc.br>
To: shellfish@kenyon.edu
QUESTION:
Mussel hatchery production is well world wide known as a no economical activity. However, I know few countries like China and New Zealand, where there is some research and production of mussel spat. I am trying to get references about this subject without much success, so I would like to exchange ideas with persons who have been involved or could have discussions on this topic, like who really does any kind of research in this area? Did anyone hear about remote settlement of mussel larvae?
In a week time, I start the conditioning of a group of broodstock to
induce them to spawn at our hatchery at the Federal University of Santa Catarina situated in the south of Brazil. We work with other molluscs too, as Crassostrea gigas, Crassostrea rizhophorae(mangrove oyster) and Nodipecten nodosus.
Does anyone have any sugestions in this trial? As I don't have plenty salt water, I am thinking about a closed system using a 400 litre tank, with 100 individuals between 6 and 8 cm. The water will be changed every 24 hours and temperature will be constant (21 C). The algae will be Tetrasemis tetrathele. I just dont have any idea about the quantity, there are a few references for oysters but none for mussels.
Eric Routledge
E-MAIL: routledg@cca.ufsc.br
Address: CAIXA POSTAL 10228
LAGOA
FLORIANOPOLIS - SC
CEP. 88062 - 970
BRAZIL
FAX. 55 48 3318653
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COMMENTS 1:
Mussels are among the few types of bivalves that we have NOT worked with here at the Milford (Connecticut, USA) Lab. I am a bit
concerned, however, that the Tetraselmis you are planning to feed the
larvae may be too big, if mussel larvae are similar to other bivalve
larvae in their feeding capabilities. Maybe someone else out there
can provide specific input on particle sizes that can be ingested by
mussel larvae.
Our feeding regimes for larvae are based upon algal packed-cell volume (determined by centrifuging the algal culture in a Hopkins tube), and assume a larval density of 10-15 per ml. Daily feeding regimes are in the range of 0.025 ml packed cells of algae per liter of larval culture to 0.15 ml packed algal cells per liter of larval culture,
increasing about linearly as larvae grow. Generally, we feed larvae
small prymnesiophyte flagellates, such as the "ISO's" and various
Pavlova strains. We have determined that larvae of several bivalves
can consume (and grow very well on) Tetraselmis, but only after they
have grown for several days on a diet of smaller algal cells. At
first feeding, the larvae we have worked with (oysters, clams,
scallops) cannot eat a cell as large as our Tetraselmis strains.
Gary H. Wikfors
NOAA, NMFS
Milford, CT USA
Gary.Wikfors@noaa.gov
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COMMENTS 2:
In Washington State (USA) the mussel industry relies primarily on a non indigenous species (Mytilus galloprovincialis). Consequently, companies must rely on hatchery produced seed. Both Coast Oyster Company and Taylor United (two of the biggest shellfish producers in the region) have a hatchery supplying mussel seed.
Madelon Mottet, Ph.D.
Alaska-Southeast Bio-Research
704 Sawmill Creek Blvd.
Sitka, Alaska 99835 USA
madelon@ptialaska.net
Tel/Fax (907) 747 3862
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COMMENTS 3:
I would agree with Gary Wikfors last post on algal species/sizes for
mussel larvae. I grew M. edulis larvae here in New York with the traditional flagellates early on, converting to the diatom Thalassiosira weisfloggi at post set. That was before we started using "Gary's" high lipid strains of Tetraselmis, which I highly recommend feeding to
shellfish just pre- and post set.
Gregg Rivara
Cornell Cooperative Extension-Suffolk
3690 Cedar Beach Road
Southold, NY 11971
516-852-8660
516-852-8662
grivara@cce.cornell.edu
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COMMENTS 4:
At Taylor United here in Washington State we have been producing mussel spat for about the last 5 years. Our farms have been supplied entirely with seed from our hatchery using Mytilus edulis galloprovincialis found here on the west coast. Our methods have evolved somewhat over this period and we are still working on improving, especially in the nursery stages. The larvae of this mussel are quite hardy and grow on the same algae we use for oysters and clams. We have about 5 species of small algae available for the larvae. This past year we have produced triploid mussels in addition to our usual diploids. We are beginning to work on conditioning broodstock for spawning because we find the natural spawning period to limit our production schedule. In the nursery these mussels are also quite hardy and are heavy feeders. Our production has been limited somewhat by algae available to the nursery. I work on the nursery and grow-out of mussels but can find answers for you about the larval rearing if you are interested. There is a group in Tasmania also commercially producing mussel seed. I don't have the name right now but will look for it.
Kurt Johnson
Taylor United Inc
kwjohn@whidbey.com
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