fish & fats...

[Magnum Man]

on another thread @GaryE ... said "Plus we humans are kind of fat, and they can't digest us well." brings up a question... I've seen warnings against feeding of some meats to fish, yet beef heart is often fed to Discus... assuming there is not typically a lot of fat on the heart muscle, but there could be...

so is this aversion to fats, just "some" fats... I've noticed Tilapia are particularly oily / fatty, when cleaning them, certainly other fish are fatty... are these fish not as often consumed by other fish??? ( whales eat herring ), for example... but they are mammals, but I think Tuna eat Herring...

is it the type of fat that's the problem???

 

[TwoTankAmin]

I am not even close to being educated on the biology of food and fish. However, I do know this. When I need to encourgage/assist the Hypancistrus plecos to spawn. I feed then Repashy Spawn & Grow. Here is the info on that food.

Spawn & Grow – Fresh Water

Conditioning Gel Premix

Our Growth and Conditioning Formula for Insectivorous and Carnivorous Freshwater Fish.

INFORMATION: This product is designed as a “recovery formula” for malnourished and stressed imported specimens, as well as for conditioning Broodstock. Also great for raising fry. This formula is high in fat and not suitable as a staple diet for most species.

And here is the ingredient list whixn is quite varied:

INGREDIENTS: Squid Meal, Krill Meal, Fish Meal, Schizochytrium Algae, Dried Brewer’s Yeast, Coconut Meal, Dried Seaweed Meal, Lecithin, Spirulina Algae, Locust Bean Gum, Citric Acid, Taurine, Dried Kelp, Dried Watermelon, RoseHips, Hibiscus Flower, Marigold Flower, Paprika, Turmeric, Calcium Propionate and Potassium Sorbate (as preservatives), Magnesium Amino Acid Chelate, Zinc Methionine Hydroxy Analogue Chelate, Manganese Methionine Hydroxy Analogue Chelate, Copper Methionine Hydroxy Analogue Chelate. Vitamins: (Vitamin A Supplement, Vitamin D Supplement, Calcium L-Ascorbyl-2- Monophosphate, Vitamin E Supplement, Niacin, Beta Carotene, d-Calcium Pantothenate, Riboflavin, Pyridoxine Hydrochloride, Thiamine Mononitrate, Folic Acid, Biotin, Vitamin B-12 Supplement, Menadione Sodium Bisulfite Complex).

GUARANTEED ANALYSIS: Crude Protein min. 45%, Crude Fat min. 10%, Crude Fiber max. 5%, Moisture max. 8%, Ash max. 13%.

What I do know is when I use this food for conditioning for breeding it works quite well. it also seems to promote growth in youngsters. I also do pay attention to the "warning" not to use this food as a staple. So I would feed is several times over a week to 10 days when I there is a specific need to do so.

One last observtion re beef heart. At a presentation by Dr. Tanner at an NEC weekend event for which I closed down my space in the vendor room to attend, I was most impressed when he said, "Never feed any fish beef heart." I did keep discus for a few years and I never fed beef heart. I like to call it bee farts........

 

[GaryE]

Fish fats and mammal fats are different. Fish in general can't digest animal fat. I imagine sharks who eat tourists have a miserable time pooping out undigested beer bellies.
Back before cheap air travel, sea food was expensive and unavailable in the interior. Long ago aquarists came up with a hack - goat and beef hearts were cheap, and the heart is a mammal's leanest organ. So they made beefheart recipes. There is zero reason to do that now, but this hobby hates change. The creativity of those old recipe makers was brilliant, but we dully follow their lead long after they would have replaced the mammal heart with shrimp, white fleshed fish, etc.
You can take the old recipes and do that - I use fish and sea food ingredients.

So beefheart is a true leftover. Nothing stops you from driving an oxcart to work, but there are better ways. Oh yes, and ox heart was also used a lot, but you can't find good oxen at the grocery store anymore. Cool hack though. They were clever.

 

[sharkweek178]

The way I see it, warm blooded mammals aren't a part of most fishes' natural diet. I'm no scientist but mammal flesh seems pretty far removed from insects, crustaceans, and other aquatic creatures.

 

[sharkweek178]

Fish fats and mammal fats are different. Fish in general can't digest animal fat. I imagine sharks who eat tourists have a miserable time pooping out undigested beer bellies.
Back before cheap air travel, sea food was expensive and unavailable in the interior. Long ago aquarists came up with a hack - goat and beef hearts were cheap, and the heart is a mammal's leanest organ. So they made beefheart recipes. There is zero reason to do that now, but this hobby hates change. The creativity of those old recipe makers was brilliant, but we dully follow their lead long after they would have replaced the mammal heart with shrimp, white fleshed fish, etc.
You can take the old recipes and do that - I use fish and sea food ingredients.

So beefheart is a true leftover. Nothing stops you from driving an oxcart to work, but there are better ways. Oh yes, and ox heart was also used a lot, but you can't find good oxen at the grocery store anymore. Cool hack though. They were clever.

Sharks are a little different. They burn a lot of energy with movement so they need to eat foods that are high in oils like bony fish like tunas or high fat aquatic mammals like whales or seals. Humans actually don't have enough of either fats or oils to be a good meal for sharks.

 

[Colin_T]

Fish don't digest mammal fat or meat well, and they don't digest poultry meat that well either. Yes they can live on it but it's not good for them. People can live on bread and cereals but that isn't good for us.

Years ago Jack Wattley fed discus on beef heart and liver because it was cheap and he didn't know what to feed them. It became a staple due to TFH books on discus and other freshwater fishes being fed beef heart. It's a crap food for fish and is usually full of fat. Shops that sell the stuff need to update their knowledge and get rid of the mammal meat from their fish food section.

Fish should get marine meats (prawn, fish, squid, etc) and insects and their larvae, worms, and aquatic plants. Fish don't digest terrestrial plant matter as well as aquatic plant matter. However, they digest it better than mammal meat.

 

[TwoTankAmin]

What I wonder about re plants is in the Amazon is that in the rainy season rivers etc. seriously overflow their normal banks. I remember watching a vid about fish in the Pantenal.

The Pantanal is a natural region encompassing the world's largest tropical wetland area, and the world's largest flooded grasslands. It is located mostly within the Brazilian state of Mato Grosso do Sul, but it extends into Mato Grosso and portions of Bolivia and Paraguay.

I also found this (Bold added by me):

FIELDS​

Seasonally flooded fields (locally named largoswides) are grassland landscapes with grasses that do not in occur the cerrado, but are found in Southern (Pampa and Chaco) and Northern (Amazonia) regions of South America, with species of the genus Axonopus and Paspalum, among others.

There are are herbaceous species such as: Tucum - Bactris glaucescens, Cotton - Ipomoea fistulosa, Spinning herb - Solanum glaucophyllum.

Among the trees (sparse), stand out: Piúva-de-folha-múlha-múlha-múlha-múlha-mupda - Tabebuia heptaphylla, Morcegueiro - Andira inermis.

During the flood phase, aquatic vegetation develops, such as the Erva-red - Ludwigia sp., Aguapés - Eichornia sp.

from https://www.pousoalegrepantanal.com/pantanal-vegetation