Effects of Porous Mesh Groynes on Macroinvertebrates of a Sandy Beach, Santa Rosa Island, Florida, U.S.A.

The use of porous mesh groynes to accrete sand and stop erosion is a relatively new method of beach nourishment. Five groyne, five intergroyne, and five control transects outside the groyne area on a beach near Destin, FL were sampled during the initial 3 mo after installment of groynes for Arenicola cristata (polychaete) burrow numbers, benthic macroinvertebrate numbers, and dry mass. Salinity, temperature, turbidity, and current velocity were measured at one location within the groyne site and control site. Current velocity was reduced and sand was accreted in the groyne site relative to the control site. Few significant changes or interactions (time X site) were found. Coquina (Donax), mole crab (Emerita), and several species of polychaete were not eliminated near groynes after installation of the groyne field. Arenicola cristata (polychaete) burrow numbers were higher near groynes. This is in contrast to dramatic changes often noted in the first few months after other types of beach nourishment techniques, such as sand pumping, where fauna can be completely eliminated

Eccentricity of the Apical System and Peristome of Sand Dollars (Echinodermata: Echinoidea: Clypeasteroida: Scutellina)

Eccentricity, location of structures away from a central position, is associated with directional movement. Although sand dollars have directional movement, only eccentricity of the anus is apparent. Eccentricity of the apical system and peristome is less apparent. We have found the apical system and the peristome are statistically significantly slightly anterior in Mellita tenuis, Mellita quinquiesperforata, Mellita isometra, and Encope aberrans. The apical system of Leodia sexiesperforata is central and that of Echinarachnius parma is anterior, whereas the peristome of both is statistically significantly slightly posterior. The usual selective pressure for pronounced anterior location of the mouth in animals with directional movement may be countered by the mode of feeding in sand dollars that utilizes the oral surface. The basis for the eccentricity of the apical system is not known

Nitrate Impacts on Florida Apple Snail (Pomacea paludosa) Survival and Growth

38 slides in Powerpoint presentation

A note on calculating P values from 0.15-0.005 for the Anderson-Darling normality test using the F distribution

Exact P values in the range 0.15-0.005 for the Anderson-Darling statistic can be calculated using the F distribution by modifying the asymptotic statistic A* with a simple formula. The formula calculates F* and P is calculated using [image omitted]�.EDF test,

Zoogeography and systematics of the shallow water echinodermata of Texas

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references.Not availabl

Autotomy of Globiferous Pedicellariae in the Sea Urchin Lytechinus variegatus (Echinodermata: Echinoidea)

Pedicellariae are small structures on sea urchins used in cleaning the test and in defense. In most species, when globiferous pedicellariae (one of 4 types) contact an object it causes the pedicellariae to grasp the object in a defensive reaction. Very few instances have been documented where pedicellariae are released into the water column. Lytechinus variegatus was exposed to 4 treatments of control, physical tapping, water swirling around the animal, and direct jet of water at the animal in 4 separate experiments including two live field tests, an anesthetized test, and a euthanized test. Globiferous pedicellariae were released into the water in response to the direct jet of water, with the greatest response seen in individuals tested in the field and the least response in euthanized urchins. The other treatments did not elicit a large response. Release of pedicellariae into the water may be a preemptive defense before coming in physical contact with a predator