of mantis shrimps. In healthy aquarium systems with a
harmonious fish community, the latter seldom do any
harm and are surprisingly interesting to watch. Whenever I discover a mantis shrimp (for example in live rock)
I put it in one of my aquaria. But it is a fact that no mantis shrimp can establish itself long-term where there is
an Alpheus living; after a few days there is loud cracking
in the passageway system, then silence—and the mantis
shrimp is never seen again.
One recent observation has now reinforced this particularly clearly: I obtained a splendid mantis shrimp, a
young Odontodactylus scyllarus barely 4 inches ( 10 cm)
long, from a colleague. As soon as it was introduced, it
bolted like lightning among some loose fragments of
coral and tried to disappear into a crevice. At the same
moment, the significantly smaller Alpheus pistol shrimp,
resident in the tank for years, came rushing up to the
larger, well-armed mantis shrimp (literally like a bullet
from a gun) cracking away and stirring up sediment.
It had obviously noticed the intruder—this was not a
chance encounter. It all happened faster than the eye
could resister: in a split second, the mantis shrimp was
seriously injured, floating belly-up and motionless in the
current, and disintegrated into two pieces when I made
haste to rescue it. A truly macabre, albeit impressive, execution, which gave me pause for thought.
reliable protection against mantis shrimps! And it is
precisely the latter that are among the commonest inhabitants of marine passageway systems. Of course they
are—usually—not specialized fish predators. In my aquaria at least, the occasional losses to mantis shrimps have
involved gobies (and once an Ecsenius midas), that were
either very young or had rashly chanced to enter the cave
of a mantis shrimp, out of fear or while precipitately following a piece of food.
In the wild, symbiotic partnerships form early on,
at the juvenile stage. Small bottom-dwelling gobies have
little or no armament and hence are attractive prey for
any predator. So it may be that under natural conditions
protection against the ubiquitous mantis shrimps is one
of the important prerequisites for survival!
Field biologists are once again requested...
The balance be Tween risk and reward
Could this provide a clue to the real reason for a symbiotic goby involving itself with such a dangerous landlord as an Alpheus Obviously the Alpheus would provide
references
Eichholz, I. 1998. nachzucht von Cryptocentrus cinctus. dATZ
51: 10.
Bergbauer, M. 1999. Fangschreckenkrebse. Das Aquarium 366:
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dürbaum, J. 1999. Eine Symbiose par excellence:
pistolenkrebse (Alpheidae, Crustacea) und Grundel (Gobiidae,
pisces); Videobeobachtungen im Aquarium. 5th Internat.
Meerwasser-Symposium, Bochum.
Thaler, E. 2005. “Schwerpunkt: korallenriffe”. Biologie in unserer
Zeit 3: 162–165.
Wickler, W.: Gesang in der Tierwelt. In: Musik und
Musikunterricht: Geschichte—Gegenwart—Zukunft, (Ed.) M.
Liedtke. Verlag Julius klinkhardt, Bad Heilbrunn 2000, 35-43.
