Re: What is the social life of the seahorse like?

Dear Laua:


Thank you for the interesting question!  When I was in Sara Lewis' lab as an 
undergraduate at Tufts University, I observed seahorse behavior.  The 
graduate student I worked with at the time was Heather Masonjones and we 
relied heavily on earlier studies performed by Amanda Vincent.

Seahorses are fascinating fish which are related to pipefishes and sea 
dragons.  They are unusual in that there is internal fertilization in the 
male.  In other words, the males get pregnant rather than females.  
Seahorses monogamously pair-bond during the breeding season, meaning that 
one male and one female stay together throughout a whole season, unless one 
of the individuals is killed.  In the early morning, the pair reinforce 
their pair bond by performing a morning greeting.  The two seahorses rise up 
toward the surface, quivering next to each other.  The male also seems to 
glow.  This is an abbreviated version of their courtship dance, which 
precedes mating, where the female deposits her eggs into the male's pouch.  
If the pair is left alone, most of the rest of the day is spent swimming 
around the seagrass beds where they make their home, feeding on small 
crustaceans and plankton.

If many seahorses are present in one seagrass bed, they sometimes will 
aggressively attack each other - they can be quite territorial, especially 
during the breeding season.  When one seahorse attacks the other, it wraps 
its prehensile tail around the other seahorse (head, body, tail, whatever is 
convenient) which the other seahorse tries to resist.  The other seahorse 
will also usually try to retaliate by wrapping its tail around the first 
seahorse, or else it will swim away.  I've never seen a seahorse actually 
injure another seahorse, but their tails have become pretty tangled.

So that's the social life of the seahorse - courting, breeding, defending 
territory, and an awful lot of time is spent sitting still and feeding.  I 
hope this answers your question!

Sincerely,
Ingrid Dodge
Mad Scientist

Kvarnemo C. Moore GI. Jones AG. Nelson WS. Avise JC.  Monogamous pair bonds 
and mate switching in the Western Australian seahorse
Hippocampus subelongatus.  Journal of Evolutionary Biology. 13(6):882-888, 
2000 Nov.

Masonjones HD. Lewis SM.  COURTSHIP BEHAVIOR IN THE DWARF SEAHORSE, 
HIPPOCAMPUS ZOSTERAE. Copeia. (3):634-640, 1996 Aug 1. 

Vincent ACJ. Sadler LM.  FAITHFUL PAIR BONDS IN WILD SEAHORSES, HIPPOCAMPUS 
WHITEI.  Animal Behaviour. 50(Part 6):1557-1569, 1995 Dec.

Vincent ACJ.  A ROLE FOR DAILY GREETINGS IN MAINTAINING SEAHORSE PAIR BONDS.   
Animal Behaviour.  49(1):258-260, 1995 Jan.