Copepods are tiny crustaceans that can either hitchhike their way into your tank or are added deliberately, as a natural and nutritional food for your saltwater fishThis article will focus on a few of the most popular copepods for sale to feed to your reef aquarium and boost its biodiversity.
Some fish, like mandarinfish, will not do well in a new reef tank that does not have a natural population of ‘pods. There are over 13,000 species of copepods in the world. Characterizing all of those species would be the subject of a Ph.D. study textbook. That’s not my style and candidly, I don’t have the expertise to write an article of that. Where I do have a little bit of experience is with copepods as a thriving part of a reef tank and as larval fish food, you can culture.
What you will find in this article
As mentioned before, there are tons of different species of copepods, with their own unique features that make them a distinct species. But at the risk of over-simplification (often a problem when you have a simple mind like I do), what they all have in common are a tiny size, a complex development progression, and numbers to provide a great source of energy and nutrients to filter feeders and fish.
Many species of copepods live as parasites, implanting themselves within and living off of other sea creatures. However, non-parasitic, ‘free-living’ Copepods fall into two basic categories: free swimming (called pelagic), and bottom-dwelling (called benthic).
Pelagic swimmers (free-swimming)
Free swimming or pelagic copepods are able to move about in the water column. Most pelagic species survive by grazing on phytoplankton. A single copepod can eat over 300,000 individual phytoplankton cells per day.
Free-swimming species, or at least species with free-swimming larval stages, are the type that is best for feeding larval fish.
Those copepods that live on the ocean floor or on the reef (crawling around the substrate primarily, rather than free-swimming) are called benthic copepods. These crustaceans often feed on organic detritus that sinks from the seas above or feed on bacteria that feed on this material.
Development in culture
Copepods have an extremely complex developmental process and undergo several metamorphosis stages. I’m over-simplifying a bit again here, but the juvenile form (during certain stages…and unless you’re talking to an uber-geek) is called a nauplius stage (nauplii if you’re referring to a group of larvae).
You might recognize that baby brine shrimp share the same stage name.
Establishing a culture
You can encourage copepods to grow in your aquarium, simply by adding a culture to your tank. Keep in mind that you’re adding a delicious live food to your tank. But with some luck, that you can encourage by allowing safe places for the ‘pods to grow, your culture could take hold. Most commonly, that safe place is called a refugium, which often has macroalgae and other pod-favorable habitats, away from hungry mouths.
You could also build a culture using techniques similar to what I’ve described before with growing phytoplankton and rotifers.
Of course, if you really want a healthy/large populations of pods, you’re going to need to meet their specific care requirements, including food.
What are the most popular copepods you can purchase?
At the time of this article, there are 4 popular copepods for sale (cultures, that is) that can be purchased relatively easily, near me, although you may have different or better options if you live near an academic center or aquaculture house willing to share. Here is some info about the 4 most popular strains:
Tigriopus californicus pods
This species of copepod is well known for being easy to keep in captivity, which is why it has been the subject of many scientific studies. They are sold under the name Tigger, Tiger or Tigriopus californicus andare native to the Pacific coast of North America, from Baja to Alaska and have adapted to thrive in the harsh conditions of high water tide pools. These are the most commonly available copepods for sale that I see.
In these high, isolated pools, ocean water is not exchanged with each tide but instead reaches these pools only on rare occasions. As a result, these pools host the gamut of less than ideal water conditions, such as fluctuating temperature and salinity. As such, Tigger pods have adapted to withstand typical fluctuations in water quality. Your reef tank water parameters better not fluctuate wildly, and therefore I wouldn’t say that these pods are ideally suited to live in a reef tank, but since reef water quality tends to be in a pure sweet spot, they should do alright.
Tigriopus californicus should be offered microalgae as food, to boost populations. Adding them to your tank will also boost the productive clean-up-crew aspect of your tank, helping to keep the tank clean.
Tisbe biminiensis pods
The next copepod on this list of the most popular species is Tisbe biminiensis. It is an enticing food source in a reef tank, because, although this copepod is benthic in its adult form (stays close to the sand and rocks), they will occasionally swim into the water column with that characteristic jerky motion that drives all fish crazy (with hunger).
Tisbe biminiensis is also a prolific species that can easily maintain a strong population on the floor of most aquarium’s. Native to broad ranges of tropical waters, Tisbe copepods begin life as pelagic nauplius, floating about in the water column, providing food for predators of the smallest zooplankton. As adults, Tisbe biminiensis inhabits the tank floor, grazing on detritus and algae.
Adult Tisbe copepods live only about a month, but produce a new brood of larvae every few days, providing an ideal, continual stream of both cleaning adults that are nutritious prey, and free-floating nauplius that is perfect forage for corals and other predators of the smallest floating prey. Also being tolerant of a wide range of water conditions, Tisbe biminiensis is among the most ideal inhabitants of the home aquarium.
The life cycle of the Apocyclops panamensis is can be useful food for the aquarium and for larval fish, in some instances. Adults are benthic (substrate attached) and juveniles are pelagic. Apocyclops panamensis offer great nutritional value to fish and filter feeders in the aquarium and are fast breeding like Tisbe to maintain strong populations in a small space. Apocyclops copepods are omnivores, feeding on detritus and algae in addition to phytoplankton but will benefit from adding phytoplankton to the tank.
Parvocalanus crassirostris copepods
Parvocalanus crassirostris are very small pelagic copepods that can be a great food source for larval fish and filter feeders. Their tiny nauplius stage is small enough to feed filter feeders and other larvae with tiny mouths. As you may have noticed in this hobby, tiny mouths need tiny foods and the larvae from this live food might do the trick for those tiniest of mouths.
They have been successfully used as a direct feed food source for fish breeding programs. This species relies entirely on phytoplankton for food, so a healthy phytoplankton population will be essential to maintain a population. Parvocalanus crassirostris is are nutritionally rich but may require a bit more attention to properly care for and maintain in a home aquarium compared the adaptable species above, depending on conditions. Many report excellent results in aquariums with this species, however.
As I become more comfortable with the fact that I’ve become an old-timer in this hobby, I’m often amazed to look back at all the progress that has been made. Innovation and progress abound (that was a funny word choice, but I’ll leave it there) everywhere: equipment, techniques, broodstock, and live foods. I wasn’t there for the sterile, bleached aquariums of the past, but it’s amazing to think about the complex ecosystems we can create (complete with our own food chains).
Like any living thing, copepods have their own specific care requirements. You can’t assume success just by buying any old culture of copepods for sale and then plopping them in your tank that you will have success. Hopefully, this article provides an overview and jumping off point for some of the most popular copepods for sale and is the start of your investigation about how to care for and grow these amazing, tiny invertebrates in your tanks.