Reproductive Biology of the Trout Perch, Percopsis omiscomaycus (Walbaum), in Beech Fork of Twelvepole Creek, Wayne County, West Virginia

1975 ◽  
Vol 93 (2) ◽  
pp. 434 ◽  
Author(s):  
S. E. Muth
1991 ◽  
Vol 65 (6) ◽  
pp. 957-972 ◽  
Author(s):  
Ronald L. Martino

Abundant and well-preserved tetrapod footprints have been discovered in the Glenshaw Formation (Lower Conemaugh Group) in Wayne County, West Virginia. The tracks occur along at least three horizons within a 30-cm-thick stratigraphic interval about 15 m (50 ft) above the Brush Creek Limestone; they are of Missourian age. The tracks are preserved mainly as casts on the underside of thin-bedded, ripple cross-laminated sandstones and less commonly as molds in intervening dark-gray shales. Associated body fossils include Spirorbis worm tubes and washed-in plant debris. Facies characteristics indicate the tracks were formed along the margins of an ephemeral lake in a flood basin setting adjacent to delta plain fluviodeltaic channel systems. Short-lived lacustrine conditions were likely to have resulted from a seasonal tropical to subtropical climate.Most of the tracks can be assigned to the ichnogenus Limnopus, making them one of the earliest known occurrences. At least five trackways are discernible with an external width ranging from 320 to 400 mm. Limnopus glenshawensis, a new ichnospecies, is herein proposed and various morphologic and locomotion parameters are quantified. Mean values include stride/manus, 407 mm; stride/pes, 411 mm; oblique pace/manus, 313 mm; oblique pace/pes, 317 mm; pace angle/manus, 82.4 degrees; pace angle/pes, 80.5 degrees; glenoacetabular distance, 329 mm; manus length, 87.2 mm; manus width, 104.2 mm; pes length, 121.4 mm; pes width, 112.7 mm. The tracemaker was most likely an eryopoid amphibian with a total length of slightly over 1 m.


Author(s):  
Alan N. Hodgson

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.


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