Monday, March 7, 2016

Black Carp are Breeding

Black Carp - Wikipedia
The St. Louis Post-Dispatch reports the chance finding of two juvenile black carp in a ditch connected to the Mississippi that has raised concerns about a new invasive species.  Unlike the bighead, silver, and grass carp, the so called "Asian carp" threatening our major rivers, black carp have been uncommon in the wild and not known to reproduce.

Black carp (Mylopharyngodon piceus) are also called black Chinese roach which probably should have been a clue.  They have been introduced cautiously by the aquaculture industry to control snails.  Strict controls on their transport as well as birth control measures kept them in check.  Only triploid fish were permitted, those with three pairs of genes which makes them sterile.  If this idea of releasing only sterile exotic species sounds familiar, Callery pears will probably come to mind.

Black Carp - Duane Chapman USGS
Of the four Asian carp species grown in China and Vietnam for food, the black carp is most prized for their flavor.  They are harder to raise in aquaculture as they eat only snails and mussels.  Trematodes (flukes) that can infect aquaculture are parasites that potentially threaten humans.  They require snails to complete their life cycle, hence the use of black carp to limit their spread.

Several black carp with normal diploid genes have been found in rivers but the hope was that their infrequency would prevent successful mating.  Now at least one pair has successfully mated.  The Mississippi has the most diverse collection of mollusk species in the world and three-fourths of these species are listed as threatened or endangered.  The spread of black carp which can weigh up to 150 pounds is a serious threat to mollusk diversity.  Just what we needed, another $%#^ invasive species!
Harbinger of Spring - REK
Now it is officially spring at Bull Mills.  Barb found the first Harbinger of Spring so let the fun begin.  On a more pleasant note you can review March Phenology Findings here.

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