Foods for Breeding Syngnathids

Written By: | Date Posted: 09/18/2012 | 1 Comment |
Copepod detail.

Copepod detail. Photo by Stephen Begin.

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.

First Foods

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.

Juvenile Seahorse and Artemia nauplii. Photo courtesy of Louise Hines

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.

Differences between copepods.

Drawing courtesy of Jesse Claggett.

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 bbs2, copepods
(Euterpina acutifrons)
9mm pelagic
H. coronatus Crowned Seahorse bbs + copepod nauplii
(Tigriopus japonicus)
14.5 mm
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
(Euterpina acutifrons)
6 mm pelagic
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
Sea Dragons
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
Pipefish
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
Ghost Pipefish
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 0 survival.
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 Sizes

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 µm
Newly Hatched Brine Shrimp
(San Francisco strain)
Artemia franciscana 400 µm
L Strain Rotifers Brachionus plicatilis 200 – 360 μm
S Strain Rotifers Brachionis rotundiform 150 – 220μm
Saltwater Daphnia Moina salina 2 – 3mm 500μm
Saltwater Mysis Americanmysis bahia
(Mysidopsis bahia)
4.4 – 9.4 mm 500 μm
Apocyclops panamensis Apocyclops panamensis 600 – 700 µm 70 µm (wide)
120 um long
Euterpina accutifrons Euterpina accutifrons 500 – 600 µm 50 – 60 µm
Nitokra lacustris1 Nitokra lacustris 237 µm 100 µm
Parvocalanus crassirostris Parvocalanus crassirostris 200 – 300 µm 40 – 100 µm
Pseudodiaptomus serricauldatus Pseudodiaptomus serricauldatus 700 – 850 µm 65 – 70 µm
Reef pods Tangerine Unknown 2 – 2.5 mm 100 – 200 µm
Tigger Pods3 Tigriopus californicus 1000 – 1400 µm 100 – 150 µm
Tisbe biminiensis2 Tisbe biminiensis 700 – 1000 µm 55 – 140 µm
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.

This document is intended to be a “living document” and will be updated as more information is discovered. If you have new information to add to this article, please email webmaster@fusedjaw.com

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.

Juvenile Hippocampus erectus

Juvenile Hippocampus erectus hunting. Photo courtesy of CritterHeaven.

References

Krejci SE, Lin J, Turingan R (2011).. Variations in Feeding Kinematics of Western Atlantic Seahorses. Presented at: Fifth International Public Aquarium Husbandry Series: Husbandry, Management and Conservation of Syngnathids Symposium; 2011 Nov 2-4, Chicago, IL

Gardner, T. (2003). The copepod/Artemia tradeoff in the captive culture of Hippocampus erectus, a vulnerable species in lower New York State, in: Cato, J.C.; Brown, C.L. (Ed.) (2003). Marine ornamental species: collection, culture and conservation. pp. 297-303

Thompson, Vanessa J. & Dianne J. Bray (2009). Pygmy Seahorse Hippocampus bargibanti.
Accessed 18 September 2012. http://foa.webboy.net/species/Hippocampus/bargibanti in Fishes of Australia http://foa.webboy.net/

(2005) Pygmy Seahorse  Birth and Incubation. Accessed 18 September 2012. http://homepage2.nifty.com/tatsuro33/pigumi050423.htm in Journal of Breeding and Rearing Seahorses.

Young Don, Jung Min, Lee Young – Don, Noh Gyoung – Ane (2006). Parturition and Early Growth of Crowned Seahorse, Hippocampus coronatus in Korea in Korean Journal of Aquaculture 19, Issue 2, 2006.5, 109-118

A. Murugan, S. Dhanya, R.A. Sreepada, S. Rajagopal, T. Balasubramanian (2009). Breeding and mass-scale rearing of three spotted seahorse, Hippocampus trimaculatus Leach under captive conditions, Aquaculture, Volume 290, Issues 1–2, 4 May 2009, Pages 87-96, ISSN 0044-8486, 10.1016/j.aquaculture.2009.01.033.

Robert A. Burhans (undated). Pipefish Husbandry & Propagation. Accessed 18 September 2012 in http://www.utahreefs.com/articles/Pipefish_final.pdf

One Response to “Foods for Breeding Syngnathids”

  1. reinhard Says:

    can you provide a source whee i can get a culture of Nitokra lacustris copepods ?
    thank you
    reinhard

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