Squid is a LOT of water weight compared to a lot of the market shrimp / prawn we feed rays. Yes, they do offer some stuff that shrimp lack - but a mixed diet is still best to use. Think about what each species of ray would be getting in the river, and shoot for that mix of food/nutrient intake for them.
Squid
- Thread starter omojena
- Start date
coeus;3383651; said:
i feel like someone explained the essential amino acids to you wrong, they are the amino acids OUR bodies cannot synthesize, these may be different in different organisms and i doubt their have been studies about this on fresh water rays
its still probably pretty nutritional, just thought that term should be used correctly, 3 years of high school biology taught me the vocab pretty good
Essential amino acid requirements are pretty consistent for all vertebrates. The biochemistry that limits our ability to synthesize certain amino acids is highly conserved evolutionarily.
I don't know know of studies specifically looking at rays but a number of studies have examined the amino acid requirements of various fish species since the 1950s (if you want to look them up John Halver was one of the main guys who did a lot of the work).
According to my old marine bio textbook the essential requirements for chinook salmon (based on Halver's initial test diet) are: arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Quantitative requirements vary slightly from species to species (eg. salmon need more arginine and catfish need less threonine).
omojena;3387877; said:
Is Hikari claiming proprietary information for rays specifically or just fish in general? If the latter that seems a little odd given that a lot of this stuff was published decades ago.
For those of you with access to a library you can check out this reference for a comprehensive review of the required amino acids:
Wilson RP, Halver JE. Protein and amino acide requirements of fishes. Ann. Rev. Nutr. 1986. 6:225-44
They show the required amounts of all the amino acids as a % of total diet and a % total protein. They review chinook and coho salmon, carp, japanese eel, channel cats, lake trout, rainbow trout, bream and tilapia. Not really aquarium fish but the requirements are pretty similar across the board which would suggest that they should also be similar for most aquarium fish.
