Brine Shrimp vs Copepods - Which is best?

The Marine hobby is subject to a lot of heresy. 'My uncle's mate's sister's cousin's boss's son did it so I trust them and I am sure it works'. It leads to some breakthroughs, to be fair but also some disastrous practices and other things which whilst aren't particularly harmful, are just kind of wrong.

One of those things that is 'just wrong', is how much more popular Copepods are than Brine Shrimp. Now, before you jump down my throat, I will start by saying that Copepods ARE great. They absolutely deserve their place in aquaculture, but before you decide I'm a crazy person and close this blog, I implore you to read on. PLEASE. I beg.

First off, Copepods are not all made equally. At current, there are about 13000 described species of Copepods. Realistically, there may be closer to 20000. To give some context, there are only about 6500 species of Mammals. That is almost as much 'Diversity' as the judge's panel of any given British Television Talent Show.

Copepods are divided over 10 orders, with the majority of species you may be familiar hailing from the orders Calanoida, Cyclopoida and Harpacticoida.

Copepods are wildly diverse. WILDLY. Some Copepods are parasites of Whales, whilst others survive on rotting leaves in damp soil of the Amazon. Each species fills a niche, often uninhabitable by other 'pods'.

Time for a tangent.... Being a fly on the wall of marine shops, I have heard some simply wild takes. Which actually aren't quite so wild. But they are, if you stick with me. Here are a few

1. Copepods will stop your fish getting white spot

2. Copepods will clear a tank of Diatoms

3. Copepods will increase water quality

4. Copepods will reduce mulm and detritus in a tank

Now in the context of an aquarium, the points above are highly unlikely to occur. Now, I am not a scientist, so I can neither prove for nor against but practically, if we look at the species available to the hobbyist, I can confidently say that this is not going to happen.

Which species are available in the hobby then?

The two most common Copepods you will encounter are Tigriopus (Harpacticoid) and Pseudocalanus (Calanoid). The former is a rockpool species which thrives in higher temps and strong Phytoplankton concentrations. The latter on the other hand is a Coldwater, Pelagic species which requires Isochrysis and similar golden Phytoplanktons to breed and thrive. Long story short, neither are likely to form stable populations or do much positive work in a reef tank without temperature ranges being way out for Coral and Fish, or Nutrient/Plankton concentrations being too high for an ornamental aquarium.

Big twist? If you are buying frozen Copepods, you may be surprised to hear that you are actually buying Freshwater Cyclops. I guess it checks out though, they are still Copepods!

OK, but you can see Copepods swimming around in your tank? Those are probably incidental. Brought in on Coral and Live rock and they are probably surviving well in low population densities. Get them under a scope and see if you can ID them. They are unlikely to be a species which can be cultured en-masse, but they will certainly help as a clean up crew in your tank.

So, to summarise, using Copepods in your reef aquarium is more or less as a feed ONLY. You are not helping to cycle the tank, build a fauna population or keep the tank clean. They are just feed. Well, they are a good feed! Copepods are full of essential fatty acids and the small size makes them perfect for Pipefish, Mandarins and other small species. Most Anthias are specialised Copepod feeders too, so they are useful when fed regularly to newly imported Anthias and similar species. Copepods are also ideal for feeding Corals, too!

On the other hand, using shop bought Copepods are useless in aquariums without fish and aquariums with only large fish species. They will die, rot away and ad to your bioload. Not good!

So, this is where Brine Shrimp comes in.

Brine shrimp was one of, if not, the first cultured live fish food. Highly culturable, very high in nutrients if enriched before feeding (Our brine shrimps are high in HUFA and fatty acids) and palatable to almost all marine species!

One of the key differences between Copepods and Brine Shrimps is juts how much you get per bag. Buy a bag of each and compare the difference. Now throw both bags into your tank at the same time and see which your fish go after first. You might be shocked (Insert clickbait youtube face here)

To summarise - I suppose what I am trying to say is that for the vast majority of reef keepers, a bag of Brine Shrimp will be far more well received and useful to your tank than a bag of brine shrimp. Try it, and let us know your findings!

Brine Shrimp

Buy Now