Mating Behavior of Macrobrachium crenulatum
Posted: Mon Jun 30, 2008 7:57 am
Yesterday evening, I video-taped mating behavior in some M. crenulatum I recently shipped back from Puerto Rico: http://www.vimeo.com/1256512.
As far as I know, this is the first such footage ever taken for crenulatum. The female was being temporarily housed in a plastic "Kritter Keeper" submered within the larger aquarium where the male was residing. I had offered shrimp pellets to all of my new shrimp the night of their arrival; this female crenulatum was the only one to leave the food untouched. I attributed this to the stress of transport, but around 1 PM the following day, I noticed it to have molted. The cast shell, suprisingly enough, was left completely untouched. Around 12 hours later, I happened to observe the male probing the top of the plastic container, and opened the lid to see what happened next.
The eggs (thousands upon thousands, and quite miniscule) descended amongst the pleopods around 30 minutes later. In the meantime, the male set about consuming the fresh exuvium, which seemed compellingly similar to the "nuptial gift" phenomenon in certain predatory insects and arachids. At present, I don't have any other data points for crenulatum, so it's impossible to determine whether the male's meal was incidental or par for the course.
I was surprised that the female cuticle remained soft enough for spermatophore placement so long after molting. Perhaps anti-hardening agents are released into the post-ecdysis exoskeleton by reproductively receptive females, since the window of opportunity for mating might otherwise be quite narrow if population density is low or concentrated downstream of the female's pool.
I will try to rear the resultant young.
As far as I know, this is the first such footage ever taken for crenulatum. The female was being temporarily housed in a plastic "Kritter Keeper" submered within the larger aquarium where the male was residing. I had offered shrimp pellets to all of my new shrimp the night of their arrival; this female crenulatum was the only one to leave the food untouched. I attributed this to the stress of transport, but around 1 PM the following day, I noticed it to have molted. The cast shell, suprisingly enough, was left completely untouched. Around 12 hours later, I happened to observe the male probing the top of the plastic container, and opened the lid to see what happened next.
The eggs (thousands upon thousands, and quite miniscule) descended amongst the pleopods around 30 minutes later. In the meantime, the male set about consuming the fresh exuvium, which seemed compellingly similar to the "nuptial gift" phenomenon in certain predatory insects and arachids. At present, I don't have any other data points for crenulatum, so it's impossible to determine whether the male's meal was incidental or par for the course.
I was surprised that the female cuticle remained soft enough for spermatophore placement so long after molting. Perhaps anti-hardening agents are released into the post-ecdysis exoskeleton by reproductively receptive females, since the window of opportunity for mating might otherwise be quite narrow if population density is low or concentrated downstream of the female's pool.
I will try to rear the resultant young.
