There are rumors being spread on the Internet that the Tigriopus californicus species of copepod is a cold-water species and will either quickly die or not reproduce in the warmer waters of a reef system. As with any rumor, there is a small bit of truth, and a lot of bad information.
Tigger-Pods is the copyrighted trade name for Reef Nutrition's product containing thousands of live Tigriopus californicus copepods. They are cultured in tanks inside a greenhouse at water temperatures ranging from 65 to 85 °F.
While it is true Tigriopus californicus come from the west coast of North America, they have a vast reported range from the tip of Baja California (Mexico) to Alaska. That is just the reported range on paper; it doesn’t mean they are not found outside of that range. People have reported seeing them further down the Pacific West Coast, as far as Honduras.
Climate / Temperature
They do not live in the open ocean - they live in the warm upper splash zone tide pools. They are not adapted to survive in the kind of environment that the open ocean typically provides. Anyone who has spent any time tide-pooling in the upper splash zones of the coast of California can tell you the upper pools can experience extended periods (days to weeks) of daily highs in the mid to high 90’s (°F) during summer.
Also, see "Habitat characters of Tigriopus californicus (Copepoda: Harpacticoida)" from the Journal of the Marine Biological Association of the United Kingdom where copepod populations were found at water temperatures of 6–33°C (42F to 92F).
Reproduction Above 74°F
It is a myth that all Tigriopus californicus do not do well in warm conditions originates from mis-interpretation of a research study of Canadian populations. In these samples from much colder water, it was found that 2-5% more males than females were produced when cultured above 75°F. Such a slight departure from a 50:50 sex ratio will have a negligible effect on the breeding success of a population. Furthermore, although this temperature effect may occur in the cold–water adapted strains collected for that trial, no similar studies are reported of populations from warmer waters. Reed Mariculture’s Tigger-Pods were originally collected in California, over a 1,000 miles further south. Our Tigriopus californicus have been cultured successfully at near reef temps (mid 70's to 80's during the summer) for several years now.
Tigger-Pods are significantly larger than most copepods that come in with live rock. Most such pods are between 300-500 microns, while Tigger-Pods are 1000-1500 microns. It's difficult to find microplankton in this size range, so Tigger-Pods can be a valuable addition to your reef system.
Tigger-pods will typically not thrive in your main tank for three reasons:
- there is no place for them to hide, and they are such attractive food that they get eaten quickly and disappear
- there is not enough food (microalgae) for them
- it takes 20-30 days from when their eggs are laid until they mature into breeding adults ready to start laying eggs, so the chances that they can persist long enough to breed under these conditions is practically zero.
The best way to culture Tigger-Pods is to put them in your sump or refugium where they are safe, or culture them in a separate tank. Either way, give them lots of microalgae (like Phyto-Feast) to feed on.
The bottom line is that Tigger-Pods (Tigriopus californicus) are a very good species of copepod to have in your reef system. They are a highly adaptable species that thrive at cold temperatures, reef system temperatures, and intermediate temperatures. They are also very good feed organisms (easy to capture and a good nutritional profile), and will culture well when given the right conditions and food.