Reply To: Reidi or Fuscus

Dear Joe:

That’s an easy choice, sir – Hippocampus reidi is one of the most difficult species of seahorses to raise in the world (virtually impossible for a home hobbyist), whereas Hippocampus fuscus is perhaps the easiest of all seahorse species to raise. Go with the Hippocampus fuscus, Joe.

For example, this is what my new book says regarding the difficultly level of raising newborn Hippocampus reidi seahorses:

Ease of Rearing:
Hippocampus reidi fry are notoriously difficult to raise. Along with the closely related H. ingens, these Brazilian beauties are considered the second hardest species to rear after the Hawaiian seahorse (Hippocampus fisheri). The Brazilian breeding machine – Hippocampus reidi – is the most prolific of all the seahorses (Abbott 2003). They have a well-deserved reputation for churning out brood after brood every two weeks with relentless regularity, and hold the world record for delivering ~1600 young in a single brood (anecdotal reports of broods up to 2000 fry are not uncommon)! Not bad for a livebearer. But with that many fetal fry crammed into one incubator pouch, the inevitable tradeoff is that the young are born at a considerably smaller size than most seahorses (Abbott 2003). The newborns are too small to accept newly hatched Artemia nauplii as their first food, and must therefore be fed on copepods and rotifers initially, which are much more difficult to culture and provide in large numbers. They also go through a lengthy pelagic phase, drifting freely with the plankton for up to 1-2 months, which makes H. reidi fry notoriously difficult to raise (Abbott 2003).

Contrast that with what my new book has to say regarding the ease of rearing billboard at the Hippocampus fuscus:

Ease of Rearing:
About as easy as it gets! H. fuscus fry are suitable for the easy rearing method. Small broods of large, well-developed benthic fry that can take Artemia nauplii (newly hatched brine shrimp) as their first foods make this one of the very easiest seahorses to raise. H. fuscus is quite comparable to H. zosterae and H. capensis in ease of rearing.

In short, Joe, if breeding is a consideration, then Hippocampus fuscus wins hands down!

Here is my complete species summary for Hippocampus fuscus, sir:

Hippocampus fuscus (Tropical, Benthic)
Common name: Sea Pony, Black Sea Pony or Black Seaponie.
Scientific name: Hippocampus fuscus Ruppell 1838
Synonyms:
Hippocampus brachyrhynchus
Hippocampus natalensis
Maximum size: 5 inches (12.5cm).
Climate: tropical: 20 degrees S to 20 degrees N
Distribution:
Indian Ocean (Sri Lanka) and Red Sea.

Meristic Counts:
Rings: 11 trunk rings + 34 tail rings (tail rings vary from 33-37).
Dorsal fin rays: 16 rays (varies from 14-17) spanning 2 trunk rings + 1 tail ring.
Pectoral fin rays: 15 soft rays (varies from 14-16).
Morphometrics:
Snout Length: 2.7 (2.4-3.0) in head length.
Other distinctive characters:
Coronet: usually low and insignificant so that the arch of the neck forms a smooth unbroken curve; sometimes slightly raised and rough in texture.
Spines: low to slightly developed (smooth bodied).
Key Features: head appears large compared to the size of the body.
Adult Height: 3 to 4-3/4 inches (8-12cm).

Color and Pattern:
As its common name suggests, the Black Sea Pony (H. fuscus) is usually dark in color but bright yellow specimens also occur. Background coloration varies from pale yellowish brown to dark gray to black, often with large pale areas or saddles on its back. A large whitish patch on the back of the neck is typical of many specimens and may be diagnostic for this species in some areas (Kuiter 2000).

Breeding Habits:
Breeding Season: unknown; may breed year round in captivity.
Gestation Period: about 18-24 days (varies with water temperature).
Egg Diameter: 1.8 mm.
Brood Size: 10-120 fry; typical brood size is about 80.
Size at Birth: about ~1/2” (10 mm).
Onset of sexual maturity: 4 months at about 2 inches (4-5 cm) in length.
Pelagic/Demersal (benthic): fry are benthic from birth.
Ease of Rearing:
About as easy as it gets! H. fuscus fry are suitable for the easy rearing method. Small broods of large, well-developed benthic fry that can take Artemia nauplii (newly hatched brine shrimp) as their first foods make this one of the very easiest seahorses to raise. H. fuscus is quite comparable to H. zosterae and H. capensis in ease of rearing.

Natural Habitat: algal reefs or eelgrass beds (Zostera sp.) in shallow protected lagoons from 3-33 feet (1-10 meters) deep.
Natural History:
The Sea Pony has not been studied in the wild and little is known about the natural history of H. fuscus. It is believed to be monogamous since adults pair bond and conduct daily greetings in the aquarium (Lourie, Vincent & Hall 1999). These are diurnal seahorses that are active by day.
Females produce large eggs 1.8 mm in diameter with clutches ranging from 30-140 eggs. After receiving these ova, males give birth to broods of 10-120 young after a gestation period of 18-24 days.

Preferred Parameters:
Temperature = range 72F to 78F (22C-26C), optimum 75F (24C).
Specific Gravity = range 1.022 – 1.026, optimum 1.0245
pH = 8.2 – 8.4
Ammonia = 0
Nitrite = 0
Nitrate = 0-20 ppm
Suggested Stocking Density: 1 pair per 5 gallons (20 liters).

Aquarium Requirements:
The Sea Pony (H. fuscus) has no special care requirements and is generally quite tolerant regarding aquarium parameters. These hardy little seahorses should thrive in a standard SHOWLR tank equipped with a good protein skimmer and heavily planted with Caulerpa and other macroalgae to simulate its natural eelgrass habitat.

Juvenile Rearing Tanks:

H. fuscus has proven to be very easy to raise. They can be raised in a basic benthic nursery using the easy rearing method and do well on newly hatched brine shrimp (Artemia nauplii). Survivorship is generally very good and success rates are high.

Wolfgang Mai has been very successful rearing H. fuscus using the following methods described below. He prefers a bare-bottomed in-tank nursery about 4 by 12 inches (10 x 30 cm) suspended within a larger host aquarium (Mai 2004b). Mai finds a nursery this size will comfortably house up to 80 fry (Mai 2004b) providing there are plenty of artificial hitching posts (plastic grids). He cautions that the benthic fry will perch on each other if insufficient holdfasts are provided, thereby interfering with efficient feeding, and notes that artificial hitching posts are much easier to clean and sterilize than live Caulerpa (Mai 2004b).

The tops of his in-tank nurseries are covered with mesh to allow uneaten Artemia nauplii that have lost most of their nutritional value to escape (Mai 2004b). Mai cleans out his suspended nurseries between feedings by lifting the inner fry tank halfway out of the host aquarium and then resubmerging it, which flushes out the detritus and debris that accumulates on the bottom (Mai 2004b). This has the added benefit of flushing any excess Artemia remaining from the last feeding out of the nursery. In between feedings, fecal pellets are siphoned off the bottom as often as possible using a length of airline tubing (Mai 2004b).

Over the next 30 days, Mai keeps a close eye on the developing fry and separates the fast-growing young from the smaller fry that are lagging behind (Mai 2004b). The slow-growing fry are weeded out from their bigger brethren and transferred to separate grow-out tanks for further rearing, so that all the young have been segregated by size after the first month or so (Mai 2004b). Mai begins offering the young frozen food every now and then during this period to supplement their staple diet of live Artemia and gradually accustom them to nonliving food (Mai 2004b).

He uses the smallest possible grow-out tanks at this point in order to maintain an adequate feeding density for the young. The bare-bottomed rearing tanks are siphoned off 2 or 3 times daily to remove fecal pellets and detritus (Mai 2004b). Once a week, the entire tank and all the artificial hitching posts are cleansed and scrubbed thoroughly with hot water and a brush (Mai 2004b). The young fuscus are removed with a strainer for this procedure, and Mai finds that exposing the juveniles to the air at this stage of their development causes them no harm whatsoever (Mai 2004b).

At the age of two months, the juveniles need more room and are transferred to larger bare-bottom rearing tanks for further growth (Mai 2004b). Mai maintains the same regimen of daily siphoning and weekly tank (and hitching post) scrubbings (Mai 2004b). He warns that skimping on this regular maintenance will result in the formation of a bacterial slime that covers everything in the tank and sickens the seahorses (Mai 2004b).

The juveniles mature at the age of about 4 months when they have reached a size of 4-5 centimeters or about 2 inches (Mai 2004b). They are ready to be transferred to the display tank when they are around 4-5 months old. Mai notes that transferring the young to a large, decorated aquarium too early will severely impact their growth and health (Mai 2004b).

Diet, Nutrition, and Feeding Techniques:

H. fuscus fry can be started on newly hatched Artemia nauplii. They grow rapidly and should be offered progressively larger (older) brine shrimp nauplii as they develop and mature. Its important to enrich brine shrimp older than 8 hours once they reach Instar II and beyond.

Mai has determined that the best growth is achieved newly hatched Artemia nauplii12-16 hours old that have refrigerated at 41-45 F (5-7 C) for 24-36 hours to keep them in an arrested state of development and enriched with fatty acids and vitamins throughout this period of suspended animation (Mai 2004b). The metabolism and growth of the Artemia slows to a virtually standstill when refrigerated, allowing the nauplii to retain most of their yolk sacs and remain small enough for even newborn fry to accept even after 2 to 3 days of continuous enrichment (Mai 2004b). This method of enrichment produces brine shrimp nauplii with unsurpassed nutritional value. See the chapter on rearing for more information on the refrigeration method of fortifying brine Artemia nauplii.

The fry grow rapidly on this diet, putting on their most substantial growth from days 6 to 25, during which time they gained an average of 1 millimeter in total length per day (Mai 2004b). After this initial growth spurt, the growth rate of the fuscus fry slowed again, so they grew about 2 millimeters per week between day 25 and day 40 (Mai 2004b).

The young are ready to be weaned onto defrosted Artemia nauplii and chopped frozen Mysis by the age of 6-8 weeks and rapidly learn to eat such nonliving prey. By the age of 2 months, most of the juvenile fuscus should be eating frozen baby brine shrimp and small defrosted mysids as their staple diet (Mai 2004b).

Adult H. fuscus are aggressive feeders that are very easy to feed. They greedily accept all the usual live foods and frozen fodder, thriving on enriched frozen Mysis as their staple diet. Mai reports that the adults thrive when feed frozen foods 3 times a day (Mai 2004b). He feeds a combination of freshly thawed Mysis shrimp and defrosted adult brine shrimp, and notes that his seaponies much prefer the Mysis (Mai 2004b). This means the 2 types or frozen foods should never be offered at the same time or the seahorses will concentrate on the mysids and ignore the Artemia. For best results, he recommends providing each adult with 10-20 Mysis shrimp or adult shrimp over the course of the day, with the Artemia comprising about 20% of their daily diet (Mai 2004b).

Discussion:

H. fuscus is very similar to the charming Cape Seahorse (H. capensis) in appearance and behavior. Both species are closely related to H. kuda and are likely offshoots of the kuda complex. It may be helpful for hobbyists to think of H. fuscus as a warm-water version of H. capensis that shares its many desirable traits.

As such, this is the perfect seahorse for the aquarium. Even wild-caught H. fuscus are very hardy (Garrick-Maidment 1997). Once they have been captive-bred for a few generations, these sea ponies will be all but bulletproof. Wild specimens are very easy to wean onto to a diet of nonliving foods and captive-bred H. fuscus thrive on a staple diet of frozen Mysis (Garrick-Maidment 1997).

H. fuscus is seldom seen in the US and captive-bred specimens have never been available to hobbyists. This prolific species is ideally suited for aquaculture and has long been raised on a limited basis in Europe and the UK. In view of this, I am always amazed that H. fuscus is not already being worked by one of large seahorse farms in Australia or the USA. That will surely change and it is only a matter of time before a line of captive-bred H. fuscus appears on the market. In this case, perhaps it will be Kealan Doyle at Seahorse Ireland who leads the way.

One thing is for certain — once Carol Cozzi-Schmarr in Kona, Hawaii or Tracy Warland in Port Lincoln, Australia get their hands on sufficient H. fuscus broodstock, they will have an instant hit on their hands. Hobbyists will find a tropical seahorse that has all the virtues of captive-bred H. capensis but without any temperature concerns whatsoever to be virtually irresistible. A multigenerational line of H. fuscus has unlimited potential and could quickly become the most popular seahorse in the ornamental fish industry, surpassing even such perennial favorites as H. erectus and the ever-popular dwarf seahorse (H. zosterae) in that regard. (H. fuscus is much easier to breed and raise than H. erectus and both larger and easier to feed than H. zosterae.)

Bottom Line:

Nearly indestructible when farm-raised, H. fuscus is the ideal “starter” seahorse, and is highly recommended for beginners. A great choice for breeding projects.

Together with H. erectus and H. zosterae, the Sea Pony (H. fuscus) gets my top recommendation. If you ever have a chance to acquire captive-bred fuscus, snap them up!

Additional Information (to learn more about Hippocampus fuscus, please consult the following references):

Hippocampus fuscus, Sea pony. 27 Feb. 2004. Fish Base.
<http://www.fishbase.org/Summary/SpeciesSummary.cfm?id=25955&gt;

Mai, Wolfgang. 2004b. “Improved Techniques for Raising Hippocampus kuda and H. fuscus.” Coral. Vol. 1, Num. 1. February/March 2004.

©Copyright 2009. All rights reserved. Permission to reproduce is granted by the author (Peter Giwojna) for your personal use only and is not transferable without written permission by Ocean Rider and the original author.