Patterns of Development in Florida Opisthobranchs (Mollusca: Opisthobranchia: Gastropoda)
The developmental pattern of invertebrates is a significant component of life history, influencing population distribution, recruitment, genetic variation, and extinction. The most recent study examining developmental strategies in Florida opisthobranchs focused on one group of opisthobranchs (Order Ascoglossa). The purpose of this study is to examine developmental patterns in opisthobranch mollusks from the five major orders of opisthobranchs from Florida. Specimens were collected from sixteen sites: 8 sites in the Florida Bay and 8 sites in the Atlantic Ocean. Living specimens were maintained at Keys Marine Laboratory (KML) in Long Key where species were identified and cultured to document embryonic development and determine developmental mode. Twenty-one percent of collected species (n = 3) spawned in the laboratory. The size of spawn, size and volume of the egg capsules, and egg diameter were recorded upon deposition. Embryonic development was observed daily through hatching. Mode of development was inferred for embryos not surviving through hatching. Egg diameter ranged from 140-158 µm. Two species, Haminoea antillarum and Phyllaplysia engeli were determined to have Type 3 development. Based on the small number of eggs per mass and large egg diameter, development for the third species, Ercolania fuscata, is hypothesized to be either Type 2-lecithotrophic or Type 3-encapsulated development. Based on these results and modes of development documented in the literature record for Florida opisthobranchs (n = 56), the Florida opisthobranch fauna appears to be predominately Type 2 (lecithotrophic) or Type 3 (direct development), in contrast to Thorson’s Rule.
Virginia Wesleyan College
P31 • William H. Dees1, Adam D. Richard1, Jesse P. Dupre1, Sawyer M. McMicken2, Caleb M. Ardizzone1, Omar E. Christian2, Cecilia W. Richmond3, Jill Hightower4, Janet R. Woolman3
The Effect of Extracts and Freshly-Cut Parts From Louisiana Native Plants on Aedes aegypti Mosquitoes
We evaluated the effect of extracts and freshly-cut parts from plants native to Louisiana on female Aedes aegypti mosquitoes. The following plants were used in making hexane, acetone and methanolic extracts: Rattlesnake Master, Eryngium yuccifolium, Cluster Bushmint, Hyptis alata, and Wooly Rose Mallow, Hibiscus lasiocarpus. The following plants (and plant parts) were used in experiments of freshly-cut plants: E. yuccifolium (leaves and flowers), Coreopsis, Coreopsis lanceolata (leaves and petals), American Beautyberry, Callicarpa americana (leaves and unripe berries), and Slender Mountain Mint, Pycnanthemum tenuifolium (leaves and flowers). For the extract experiments, mosquitoes were placed in standard glass Petri dishes treated with extracts. For the experiments with plant parts, standard plastic Petri dishes were used to hold mosquitoes and cut plant parts. A 10% sucrose solution served as a food source for mosquitoes during the Petri dish tests. We recorded percent mortality at 24, 48, 72 and 96 h. We also recorded percent mortality at 168 h for the extract experiments. We observed 57% mortality in adult mosquitoes after 24 h exposure to methanolic extracts of E. yuccifolium buds. After 7 days (168 h), we observed 96% mortality in mosquitoes exposed to hexane extracts of Hyptis alata stems and 93% mortality in mosquitoes exposed to methanolic extracts of E. yuccifolium buds. Mosquitoes exposed to freshly-cut leaves of all plants, except P. tenuifolium, exhibited greater mortality than controls. We observed up to 85% mortality in adult mosquitoes after 24 h exposure to freshly-cut flowers of E. yuccifolium.
1 Dept. of Biology and Health Sciences, McNeese State University, Lake Charles, LA; 2 Dept. of Chemistry and Physics, McNeese State University, Lake Charles, LA; 3 Louisiana Environmental Research Center, McNeese State University, Lake Charles, LA; 4 Calcasieu Parish Mosquito and Rodent Control Dept., Lake Charles, LA
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P32 • William H. Dees1, Jesse P. Dupre1, Adam D. Richard1, Sawyer M. McMicken2, Caleb M. Ardizzone1, Omar E. Christian2, Cecilia W. Richmond3, Jill Hightower4, Janet R. Woolman3
We evaluated the effect of Louisiana native plant extracts on ovipositing Aedes aegypti mosquitoes. Bioassays were conducted in screened cages (46x46x46 cm) containing plastic cups lined with germination paper on which eggs were deposited. Each cup contained 60 mL distilled water and 10 uL of hexane, acetone or methanolic plant extracts. Extracts were made from the following plant parts: (1) stems and roots from Cluster Bushmint, Hyptis alata; (2) stems and roots from Wooly Rose Mallow, Hibiscus lasiocarpus; and (3) buds, stems and roots from Rattlesnake Master, Eryngium yuccifolium. The bioassay was conducted for 24 h. After 24 h, the germination paper in each cup was removed and the eggs on each paper were counted. We calculated the oviposition activity index (OAI) for each extract. Hexane extracts of E. yuccifolium buds and roots and the acetone extract of E. yuccifolium stems repelled ovipositing mosquitoes. Ovipositing mosquitoes were slightly attracted to hexane extracts of E. yuccifolium stems, methanolic extracts of Hyptis alata roots and methanolic extracts of E. yuccifolium stems and roots. Ovipositing mosquitoes demonstrated the greatest attraction to acetone, hexane, and methanolic Hibiscus lasiocarpus root extracts. The OAI ranges for the H. lasiocarpus root extracts were (+)0.32-0.41 on a scale of (+)1 (attraction) to (-)1 (repellency).
1 Dept. of Biology and Health Sciences, McNeese State University, Lake Charles, LA; 2 Dept. of Chemistry and Physics, McNeese State University, Lake Charles, LA; 3 Louisiana Environmental Research Center, McNeese State University, Lake Charles, LA; 4 Calcasieu Parish Mosquito and Rodent Control Dept, Lake Charles, LA
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P33 • Orlando Benavides, Raquel Casado, Rosario Rodriguez, Gretert Montano, Frank Coro
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