Haplochromis sp. ''Dayglow'' Cichlid-Forum  
Photo Contest
Search Library:
Search Forum »
   
The hybrid cichlid... pet or problem?
by Damian Jones (number6)
Page  1  |  2  |  3

The word "hybrid" derives from the Greek, meaning "son of outrageous conduct". The word "hybrid" in the world of cichlids has been become nothing short of controversial, if not an emotional topic for many.

Hybrid cichlids are any cross of two previously unmixed groups or bloodlines of fish. In the most common usage, hybrid refers to the crossing of any two or more species, Genus or Family of animal. Less common usage, but of importance to any breeder of cichlids, is intra-specific hybridization. This is the crossing of two distinct bloodlines, variants, or locations within a species. Some of these intra-specific crosses may be the crossing of two differently named variants, two differently colored variants, or could simply be the crossing of the same species collected from separate geographical populations.

DNA fingerprinting on the cichlids of the Rift Lakes shows that geographically separated, but similar morphs are less closely related than different morphs living side by side.(1) It is easy to understand that one can get a blending of different characteristics when you cross blue and orange fish, but it is less obvious when the fish look similar, but have hidden differences. The result is the same. The hybrid either expresses one or the other allele, or some combination of the two. We can simplify things by saying that each parent contributes one copy of each gene and they work as a pair to shape the new hybrid cichlid and its behavior.

How these two copies may work together, or not work well together, is impossible to predict. First generation hybrids of Metriaclima zebra and Labeotropheus fuelleborni show interesting results.(2) M. zebra eat particles floating in the water and therefore, their mouths and teeth are designed for this type of feeding. L. fuelleborni scrape algae off rocks with teeth uniquely designed for such a purpose. The 1st generation hybrids of M.zebra and L. fuelleborni had jaws and teeth were a melding of the two traits, but had more in common with the less specialized open water styled feeding of the M. zebra. It is not an uncommon result for specialized features or abilities to be diminished or lost after hybridization events. If this occurred naturally in the original habitat, then environmental pressures shape what happens next. If the mouth and teeth offer a competitive advantage over the specialized teeth, then the specialization can be modified or lost. If the environmental pressure that resulted in the specialization is still there, then that pressure drives a re-specialization or the hybrids may be reabsorbed by one or both of the parent species.

Is this at all unnatural? Evidence suggests not. Studies on the cichlid Pungu maclareni from the Cameroon point to this species of cichlid being the result of very recent hybridization between two species.(3) The other cichlid species in the crater lakes show a comparatively high degree of hybridization compared to average fish. In a rapidly changing environment, recent evidence suggests that hybridization, or extreme outcrossing is a way for individuals to get an evolutionary jump start on the competition. The term hybrid vigor has often been used to describe the extreme phenotypes commonly found after a hybridization event. Certain characteristics may be masked by being in a heterozygous (having an unalike pair of alleles) and these features may offer an advantage that other individuals do not offer. The healthiest fish get the mates, and there new genotypes are carried into the population.

Continue to next page »

Copyright © 2021 Cichlid-Forum.com. All Rights Reserved.
F.A.Q.
 
Login to access your personal folder.

0 User(s) in Chat
93720 Members
875371 Posts
681 Classifieds