Dear Vonbeamer:
If the lethargic seahorse is a male, the relative inactivity he is displaying may well be natural behavior for an animal that is adapted to a sedentary lifestyle as an ambush predator. It is normal for male seahorses to be somewhat less active than the females. Males tend to be real homebodies that will often choose one particular hitching post as their home base and spend much of there time perched right there (think of your Dad hunkered down in his favorite easy chair in the den). Researchers studying seahorses in the field therefore refer to males as "site-specific" because they can be found at the same tiny patch of reef or seagrass day after day, rarely straying from their chosen spot. Mature males are often naturally more shy and retiring than females, which can be quite brazen at times. I suspect this is due to their parental duties — during the breeding season, pair-bonded males are ordinarily ALWAYS pregnant, and they can’t risk exposing their precious cargo to any more risk than absolutely necessary.) The unfettered females tend to be far more footloose and fancy free, and in the wild they typically roam over a home territory of up to 100 square meters. So I wouldn’t worry if your male only tends to wander around the tank on occasion, whereas your female is more active and explores more.
Also, if this lethargy is a relatively recent development, and the inactive seahorse is male, it occurs to me that you may be noticing "broody" behavior. Pregnant males often become increasingly shy and reclusive. Gravid males may go off their feed as the pregnancy progresses, missing meals and failing to show up at the feeding station at the appointed time, or even going into hiding. It’s possible your lethargic seahorse may be carrying a brood of young and has become less active and relatively immobile as a result. Have you noticed any dancing, color changes, pouch displays or other indications of courtship lately?
Your water quality parameters are fairly decent, but it would be best to stabilize the water temperature in the 72°F-75°F range, which is optimum for H. erectus, and to raise your pH up a notch or two (8.2 or slightly above). You might try performing a water change to see if the seahorses respond favorably.
In short, as long as the lethargic seahorse is eating and breathing normally and otherwise behaving as usual, you needn’t be overly concerned about his behavior at this point. Make sure your water quality is up to snuff and let us know right away if he develops any more symptoms.
Best of luck with your new seahorses, Vonbeamer!
Respectfully,
Pete Giwojna
Ocean Rider, Inc. is an Organic Hawaiian-Based Seahorse Aqua-Farm & Aquarium that Follows Strict Good Farming Practices in Raising Seahorses and Other Aquatic Life.
