Foods for Breeding Syngnathids
Seahorses and their syngnathid relatives provide some interesting challenges raising from birth. Although they produce larger young than many marine species, they often ignore foods that have been the standard for raising marine fish. They must be supplied live food at birth, and each species has it’s own requirements based on size and behavior.
There are three foods that are used the most frequently when attempting to raise syngnathids; artemia nauplii (aka baby brine shrimp or bbs), copepods, and rotifers. Artemia nauplii is by in far the easiest, as it is simple to hatch and come from cysts that can be stored until needed. Unfortunately, most syngnathids fair poorly when raised on baby brine shrimp alone. This is because artemia doesn’t contain the right lipid profile that syngnathids need for growth and survival.
When artemia nauplii are used, enriching to get the right lipids is paramount to success. Many food trials have been done on different species of seahorses, and unenriched brine shrimp as a sole food source show poor survival rates. Marine animals need High Unsaturated Fatty Acids (HUFAS) in their diets. Docosahexaenoic Acid (DHA) and Eicosapentaenoic Acid (EPA) are essential to marine fish, Syngnathids included. Unlike some land animals and freshwater fish, marine fish cannot synthesis these from other molecules. While EPA is found abundantly, DHA is harder to come by.
Artemia nauplii naturally have EPA during the first few hours after hatching, which is why you will get recommendations to feed quickly after hatching. However, they still lack DHA; the only way to add it back in is by enriching with a product high in DHA.
Rotifers are usually the next options in cases where larval fish are too small for artemia nauplii. They are significantly smaller than newly hatched brine shrimp, about half the size. Unfortunately, syngnathids generally fare poorly with them. The reason isn’t exactly clear, but one hypothesis is that rotifers don’t move like typical prey items for synganthids. Rotifers use cilia to glide through water in a smooth motion. However most plankton seahorses and pipefish would naturally eat move in short, jerky bursts. While there isn’t a clear answer, use of rotifers exclusively tends to have poor survival rates.
Copepods are thought to be a better food source than brine shrimp or rotifers. They have a better nutritional profile and move in a manner that is more natural for syngnathid young to hunt. One study recently showed that seahorses use less energy consuming copepods than they do artemia nauplii, even though brine shrimp do not show evasive maneuvers that copepods do.
The down side to this is, of the three, copepods are the most difficult to raise. If you live near the ocean, collecting wild copepods is an option. But even collecting poses some challenges, like the introduction of parasites or predatory plankton. Raising cultures of copepods are best, but they can be space and time consuming, and you have to fine the right species that will thrive and produce in large numbers in captivity.
Having the right copepod is also extremely important. Some of the easiest to raise are harpacticoids which are generally benthic (preferring surfaces). Unfortunately, they don’t make the best food for newborn syngnathids, as their tendency to live on the surface of things puts them out of the view of seahorses and pipefish fry. Calanoid copepods are generally thought to be the best, as they are pelagic (free-swimming), and probably make up a big portion of the diet of young syngnathids when growing up in the wild. They are, however, more difficult to culture. Still, if you can do it, you will be rewarded with higher success rates. Cyclopoid copepods are another free-swimming copepod. While they aren’t as common in marine environment, there are a few that have been cultured and make a good food choice.
Below are the reported first foods of broods of species that have been raised successfully.
bbs = artemia nauplii
|Species||Common Name||Food||Size at Birth||Orientation|
|Seahorses Hippocampus spp.|
|H. abdominalis||Pot Bellied Seahorse||artemia nauplii||14-18 mm||hitching|
|Hippocampus alatus||Winged Seahorse||unknown|
|H. algiricus||West African Seahorse||unknown|
|H. angustus||Narrow Bellied Seahorse||artemia nauplii1||10 mm||hitching|
|H. barbouri||Barbour’s Seahorse||bbs||hitching|
|H. bargibanti||Pygmy Seahorse||unknown||2-4 mm|
|H. borboniesis||Réunion Seahorse||unknown|
|H. breviceps||Short Snouted Seahorse||bbs||14-16 mm||hitching|
|H. camelopardalis||Giraffe Seahorse||unknown|
|H. capensis||Knysna Seahorse||bbs||8-16 mm||hitching|
|H. colemani||Coleman’s Pygmy seahorse||unknown|
|H. comes||Tiger Tail Seahorse||bbs (sort of2), copepods
|H. coronatus||Crowned Seahorse||bbs + copepod nauplii
|H. debelius||Soft Coral Seahorse||unknown|
|H. denise||Denise’s Seahorse||unknown|
|H. erectus3||Souther Lined Seahorse||bbs||9 mm||hitching4|
|H. cf erectus3||Northern Lined Seahorse||rotifers, copepods||7 mm||pelagic|
|H. fisheri||Fisher’s Seahorse||rotifers + copepods
|H. fuscus||Sea Pony||bbs||10 mm||hitching|
|H. grandiceps||Big-head Seahorse||unknown|
|H. guttulatus||Speckled Seahorse||bbs||15-16 mm||hitching|
|H. hippocampus||European Seahorse||bbs|
|H. histrix||Thorny Seahorse||unknown|
|H. ingens||Pacific Giant Seahorse||rotifers + copepods – wild copepods||7 mm||pelagic|
|H. jayakari||Jayakar’s Seahorse||unknown|
|H. kampylotrachelos||Smooth Seahorse||unknown|
|H. kelloggi||Great Seahorse||unknown|
|H. kuda||Spotted Seahorse||bbs5|
|H. lichtensteini||Lichtenstein’s Seahorse||unknown|
|H. minotaur||Bullneck Seahorse||unknown|
|H. mohnikei||Japanese Seahorse||unknown||6 mm|
|Hippocampus moluccensis||Moluccan Seahorse||unknown|
|Hippocampus patagonicus||Patagonian Seahorse||unknown|
|H. pontohi||Pontoh’s Seahorse||unknown|
|H. procerus||Emperor Seahorse||bbs||hitching|
|H. queenslandicus||Queensland Seahorse||unknown|
|H. reidi||Brazilian Seahorse||rotifers + copepods||7 mm||pelagic|
|H. satomiae||Satomi’s Pygmy Seahorse||unknown|
|H. severnsi||Sulawesi Pygmy Seahorse||unknown|
|H. sindonis||Shiho’s Seahorse||unknown|
|H. spinosissimus||Hedgehog Seahorse||unknown|
|H. subelongatus||West Australian Seahorse||bbs||12.6 mm|
|H. taeniopterus||Common seahorse||rotifers + copepods||7 mm||pelagic|
|H. trimaculatus||Three-Spot Seahorse||copepods + rotifers9|
|H. tuberculatus||Knobby Seahorse||bbs||10-12 mm||hitching|
|H. whitei||White’s Seahorse||bbs||8-10 mm||hitching|
|H. zebra||Zebra Seahorse||unknown|
|H. zosterae||Dwarf Seahorse||bbs||5-9 mm||hitching|
|Phyllopteryx taeniolatus||Weedy Seadragon||instar II artemia, enriched6||20 mm||pelagic|
|Phycodurus eques||Leafy Seadragon||1 day old mysis7||35 mm||pelagic|
|Haliichthys taeniophorus||Ribbon Seadragon||rotifers + bbs||12mm||pelagic|
|Doryrhamphus dactyliophorus||Banded Pipefish||copepods8||5 mm||pelagic|
|Doryrhamphus excisus||Blue Striped Pipefish||copepods, rotifers 9||5 mm||pelagic|
|Doryrhamphus multiannulatus||mulitibanded pipefish||copepods, rotifers 10||pelagic|
|Heraldia nocturna||Upside-down Pipefish||unknown||5-6 mm12|
|Sygnathoides biaculeatus||Alligator pipefish||bbs|
|Syngnathus acus||Greater Pipefish||bbs||30 mm|
|Syngnathus scovelli||Gulf Pipefish||bbs15|
|Solestomus spp.||hybrid ghost pipefish||copepods11|
|1. Reports suggest some can take nhbs (newly hatched brine shrimp) at birth but many will need rotifers or other small prey to get started.|
|2. My own experience says they won’t eat newly hatched brine shrimp at birth and meed to be fed copepods. Specifically Euterpina accutifrons. Others have indicated they’ll consume bbs at birth but have no survival when started on it.|
|3. Northern and southern populations of H. erectus vary significantly in the size and behavior of their fry. There is some debate whether or not they are different species, which has yet to be resolved. For the purposes of rearing, they are best treated differently.|
|4. Spends most of the daylight hours free-swimming but does hitch at night from birth. It isn’t for a couple weeks until they start hitching regularly.|
|5. There are conflicting reports whether or not they can take nhbs as their first food. This is likely due to confusion around the H. kuda species and similar species.|
|6. Yolk sack lasts a few days, may not eat until yolk sack is gone.|
|7. Will not eat until yolk sack is absorbed.|
|8. One report says bbs was used, but also acknoledged the rearing tank was full of copepods and they were not fed for the first 2 days. Chances are they were initially eating copepods.|
|9. Mixed information, some say rotifers taken, other say rotifers are ignore. May be a species identification issue.|
|10. Mixed information again, some reports of them taking rotifers, some not.|
|11. Early success with copepods (to 13 days). Attempts to rear on entriched rotifers failed.|
Food size is also very important, in addition to type. Too big for a specific species, and they won’t be able to consume it, too small and it might take too much effort to find, or be ignored entirely. Dan Underwood of Seahorse Source takes the approach of feeding plankton by size, not food type. His fry get all types of plankton; such as barnacle and crab larvae, along with copepods. Below is a brief description of how he determines what to feed:
In general, we start with 120 to 330 microns for the first 3 days. Then we go to 250 to 500 for the next week. After that we go to 330 to 670 for the next week. We do overlap with the sizes as we change. Towards the end of the 2nd week, we slowly begin to add enriched Artemia. This is done primarily for H. reidi, H. kuda and H. ingens. It is also important to note that fry can consume 1 to 2 food items per minute. Multiply that out for the daylight hours and you roughly need 1,000 food items per fry per day.
The table below contains commonly raised food species, and their sizes.
|Food Organism||Scientific Name||Adult Size||Nauplii Size|
|Newly Hatched Brine Shrimp||Artemia salina||400 – 475 Âµm|
|Newly Hatched Brine Shrimp
(San Francisco strain)
|Artemia franciscana||400 Âµm|
|L Strain Rotifers||Brachionus plicatilis||200 – 360 Î¼m|
|S Strain Rotifers||Brachionis rotundiform||150 – 220Î¼m|
|Saltwater Daphnia||Moina salina||2 – 3mm||500Î¼m|
|Saltwater Mysis||Americanmysis bahia
|4.4 – 9.4 mm||500 Î¼m|
|Apocyclops panamensis||Apocyclops panamensis||600 – 700 Âµm||70 Âµm (wide)
120 um long
|Euterpina accutifrons||Euterpina accutifrons||500 – 600 Âµm||50 – 60 Âµm|
|Nitokra lacustris1||Nitokra lacustris||237 Âµm||100 Âµm|
|Parvocalanus crassirostris||Parvocalanus crassirostris||200 – 300 Âµm||40 – 100 Âµm|
|Pseudodiaptomus serricauldatus||Pseudodiaptomus serricauldatus||700 – 850 Âµm||65 – 70 Âµm|
|Reef pods Tangerine||Unknown||2 – 2.5 mm||100 – 200 Âµm|
|Tigger Pods3||Tigriopus californicus||1000 – 1400 Âµm||100 – 150 Âµm|
|Tisbe biminiensis2||Tisbe biminiensis||700 – 1000 Âµm||55 – 140 Âµm|
|1. Adults are benthic, however, nauplii are pelagic, thus the nauplii of this species may be appropriate for feeding.|
|2. Benthic copepod. May not be appropriate food, but commonly available so included in this table.|
|3. Caution advised feeding: Tigriopus spp. copepodites have been observed clawing their way out of the guts of H. kuda fry at Seahorse Ireland – observed and confirmed by Adelaide Rhodes. Tigriopus californicus has also been indicated in stress related death of non-syngnathid fish larvae due to their clinging behavior. Other copepods have been indicated in problematic behavor with fry so it is best to investigate copepod species thoroughly before committing to using for rearing syngnathids.|
A special thanks to Dan Underwood of Seahorse Source, who was willing to share his thoughts and methods as well as keep me on the right track with this article.
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