Interactions

            Paddlefish are very valuable for humans.  Their meat is white, firm, and boneless making it very similar to sturgeon in taste and texture.  Not only is the meat valued for its taste, but Paddlefish roe, or eggs, are also very valuable in that they are made into caviar.  Paddlefish are also important for humans in ways of expanding our knowledge through research and education.
            There are a number of parasitic organisms that use the American Paddlefish as their hosts.  As of today, there are six known Trematoda—Anallocreadium spathula, larval forms of Clinostomum marginatum, Cotylaspis cokeri, Diclybothrium hamulatum, Distomum isoporum armatum, and Halipegus perplexus—three known Cestoda—Marsipometra confusa, M. hastata, and M. parva—two known Nematoda—Camallanus oxycephalus and larval forms of Contracaecum spiculigerum—one known Leech, Illinobdella moorei, and one known Crustacea, Ergasilus elongatus, that prey on Polyodon spathula.  Besides these parasitic organisms, Polyodon spathula, is also heavily parasitized by the Ichthyomyzon spp. such as Ichthyomyzon castaneus, the Chestnut lamprey, or the Silver lamprey, Ichthyomyzon unicuspis.  Chestnut lampreys do not consume the whole Paddlefish, but they can weaken the Paddlefish.  However, in extreme cases, there could be a result in the death of the Paddlefish.  There can and has been as many as thirty lampreys found attached to a single Paddlefish!  To see a lamprey wound on a Paddlefish (Figure 3) or  a lamprey still attached to a Paddlefish (Figure 4) see the pictures below.

 Figure 12.  Paddlefish with a visible lamprey wound to the bottom right of the picture. 

Figure 13.  Paddlefish with a lamprey still attached as well as numerous visible lamprey wounds.


Figure 14.  Daphnia:  Paddlefish food.

            Like any other organism, Polyodon spathula can also get diseases.  As of right now, there are two known diseases that this species can get:  rostrum (paddle) degenerative disease and “Ich” infections.  Rostrum degenerative disease causes deformity of the rostrum, as well as a narrowing and/or downward curvature of the rostrum.  The causes of this disease are believed to be Aeromonas bacteria and columnaris disease bacteria which were both isolated from the rostrum.  For treatment, Chloramine-T at a rate of 20mg/L for one hour has experimentally stopped the progress of this disease in raceways, or flow-through systems.  “Ich” infections are a result of the parasite Ichthyophthirius multifilis.  Treatment of this infection consists of salt at 3ppt or raising water temperatures to 86 degrees Celsius for several days have been successful in eliminating the parasite in raceways.
            Paddlefish live in a habitat where many different and diverse organisms also live such as Daphnia spp., black crappie, zebra mussels, Lake Sturgeon, small mouth bass, bluegill, and catfish to name a few.

You thought the interactions that the Paddlefish had were interesting, wait until you get the Facts!

 

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