TN00340 RIVER PIGTOE PLEUROBEMA CORDATUM
TN00340PHYSICAL DESCRIPTION: THIS SPECIES COMPLEX IS CHARACTERIZED BY HIGHLY VARIABLE SHELL MORPHOLOGY THAT VARIES ESPECIALLY IN RELATION TO STREAM SIZE *TN5774*, GENERAL CHARACTERISTICS OF THE GENUS ARE AS FOLLOWS: SHELL ROUNDED, SUBQUADRATE, OVAL, OR SOMEWHAT ELONGATE, BEAKS PLACED ANTERIORLY, BEAKS GENERALLY PROMINENT WITH MODERATELY DEEP BEAK CAVITIES, HINGE TEETH WELL-DEVELOPED, OUTER SURFACE WITHOUT SCULPTURE, NACRE GENERALLY WHITISH *TN5774*, LENGTH RANGES FROM 37 TO 93 MM, HEIGHT RANGES FROM 31 TO 76 MM, WIDTH RANGES FROM 21 TO 51 MM *TN5761* REPRODUCTION: SPECIES IS TACHYTICTIC, WITH EMBRYO ONLY RETAINED FOR A SHORT TIME, BOTH SEXES MATURE BY 4 YEARS OF AGE, IN TENNESSEE RIVER, PEAK SPAWNING OCCURS IN EARLY SPRING, TEMPERATURE GREATER THAN 20 DEGREES C REQUIRED FOR GLOCHIDIA MATURATION, GLOCHIDIA RELEASED 4-6 WEEKS FOLLOWING FERTILIZATION, WITH PEAK RELEASES IN JUNE, GLOCHIDIA ARE 0.14 X 0.15 MM AND HOOKLESS, ROSEFIN SHINER IS ONLY HOST FISH SPECIES IDENTIFIED, GLOCHIDIA DROP OFF HOST AFTER 14-18 DAYS, HOST FISH MUST BE SMALL, FREE-LIVING NAIADS DOUBLE IN SIZE IN 3 WEEKS, GAMETOGENESIS CYCLES HAVE BEEN INVESTIGATED *TN5777* POPULATION PARAMETERS: MAXIMUM AGE IS 25-30 YEARS *TN5777*, IN 1960'S, DENSITY IN KENTUCKY LAKE BEDS ESTIMATED AT 0.234 PER SQUARE YARD *TN5761*, ALTHOUGH THIS SPECIES WAS ONCE ONE OF THE MOST ABUNDANT AND IMPORTANT MUSSEL SPECIES IN TENNESSEE RIVER AND ITS IMPOUNDMENTS, OVERHARVESTING AND INABILITY OF SPECIES TO SUCCESSFULLY REPRODUCE IN RESERVOIR ENVIRONMENTS HAVE LED TO DECLINING POPULATIONS *TN5761 *TN5765* AT PRESENT TIME, MOST POPULATIONS IN RESERVOIR BEDS ARE CONSIDERED TERMINAL *TN5765* *TN5761* DENSITIES HAVE BEEN ESTIMATED AT 0.15 PER SQ. METER IN THE CLINCH RIVER AND BETWEEN 0.10 AND 0.67 PER SQUARE METER IN THE DUCK RIVER *TN5778*
References for Life History Codes
9286
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