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Full-Text Articles in Life Sciences
Changes In Shell Morphology Of Elimia Comalensis (Gastropoda: Pleuroceridae) From The Edwards Plateau, Texas, Russell L. Minton, Scott A. Reese, Kim Swanger, Kathryn E. Perez, David M. Hayes
Changes In Shell Morphology Of Elimia Comalensis (Gastropoda: Pleuroceridae) From The Edwards Plateau, Texas, Russell L. Minton, Scott A. Reese, Kim Swanger, Kathryn E. Perez, David M. Hayes
Biology Faculty Publications and Presentations
Species in the pleurocerid genus Elimia are important components of freshwater systems in the eastern United States, but little is known about their natural history. Using dual-simultaneous linear regression and principal components analyses, we show patterns of morphological change in two populations of E. comalensis from the Edwards Plateau, Texas. Both populations had similar rates of change for all shell measurements analyzed, and both showed similar decreases in growth as total length of shell increased. However, the size at which growth slowed was different between populations, and small shells tended to have a consistent shape, while larger shells were more …
Compromised Weaponry Enhances Crayfish Tailflipping, Sandra Y. Espinoza, Zen Faulkes
Compromised Weaponry Enhances Crayfish Tailflipping, Sandra Y. Espinoza, Zen Faulkes
Biology Faculty Publications and Presentations
As a defense strategy, many crustaceans perform one of two well described stereotyped single fast tailflips (~6 ms in adult crayfish), which are triggered by a neural circuit that includes medial giant interneurons (MG) and lateral giant interneurons (LG). Tailflips can also occur without these giant interneurons firing, however; these non-giant tailflips are variable, repetitive, and significantly longer (~150 ms). Previous work showed that crayfish exposed to natural stimulus respond with a non-giant tailflip significantly faster than when presented with an artificial stimulus and that complete removal of claws lowered tailflipping threshold. We tested whether compromising weapons would influence tailflipping. …
Re-Occurrence Of The Tropical Green Macroalga, Penicillus Capitatus (Chlorophyta: Bryopsidales), In Lower Laguna Madre Of South Texas., Joseph L. Kowalski, Donald L. Hockaday, Gilbert H. Boza Jr., Hudson R. Deyoe
Re-Occurrence Of The Tropical Green Macroalga, Penicillus Capitatus (Chlorophyta: Bryopsidales), In Lower Laguna Madre Of South Texas., Joseph L. Kowalski, Donald L. Hockaday, Gilbert H. Boza Jr., Hudson R. Deyoe
Biology Faculty Publications and Presentations
The siphonaceous green alga Penicillus capitatus Lamarck is a common macroalga of the Carribean and Gulf of Mexico (Littler & Littler 2000). This shaving brush-shaped macroalga was a common inhabitant of the Lower Laguna Madre Texas (LLM) until about 40 years ago when the population was decimated following a salinity decline in the fall of 1959, another salinity reduction due to Hurricane Carla in 1961, and finally a severe freeze in 1962 (Sorensen 1963). Since that time, there have been no reports of P. capitatus in the LLM. During a reconnaissance trip in July 2006, a small population was found …
Sensory Modulation Of Crustacean Non-Giant Tailflipping, Sandra Y. Espinoza, Zen Faulkes
Sensory Modulation Of Crustacean Non-Giant Tailflipping, Sandra Y. Espinoza, Zen Faulkes
Biology Faculty Publications and Presentations
As a first step in re-examining the modulation of non-giant tailflipping, we further investigate how the presence of weapons affects non-giant tailflipping. Removing both claws significantly changes the threshold for tailflipping (Krasne and Wine, 1975; Lang et al., 1977). Claw removal affects several variables at once, however; e.g., the animal’s mass; visual stimuli associated with having claws; tactile and proprioceptive cues. For example, a crayfish with claws that are present but useless might “bluff,” and may not tailflip away from a stimuli more than an intact animal.
Effects Of Temperature And Illumination On Background Matching In Mediterranean Geckos (Hemidactylus Turcicus), Frederic Zaidan, Pamela L. Wiebusch
Effects Of Temperature And Illumination On Background Matching In Mediterranean Geckos (Hemidactylus Turcicus), Frederic Zaidan, Pamela L. Wiebusch
Biology Faculty Publications and Presentations
The ability to change skin color is a relatively common phenomenon in lizards whose occurrence is often related to crypsis. Field observations suggest that Mediterranean geckos (an often ubiquitous introduced species in many metropolitan areas of the southern United States) have the ability to lighten and darken in response to their background. On light backgrounds, the geckos were typically light pink whereas on dark backgrounds they were typically much darker with a brownish hue to their skin. This study investigated the ability to background match in this species, the main effects of temperature (20, 25, and 30[degrees]C), illumination (total darkness …
Trampling, Peeling And Nibbling Mussels: An Experimental Assessment Of Mechanical And Predatory Damage To Shells Of Mytilus Trossulus (Mollusca: Mytilidae), Carlos E. Cintra-Buenrostro
Trampling, Peeling And Nibbling Mussels: An Experimental Assessment Of Mechanical And Predatory Damage To Shells Of Mytilus Trossulus (Mollusca: Mytilidae), Carlos E. Cintra-Buenrostro
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
Shell damage, if properly recognized, can provide information about biotic interactions between molluscs and their predators. However, it can be difficult to distinguish predatory damage from mechanical breakage, thus making interpretation of damaged modern and fossil shells problematic. To establish a clear-cut distinction between antemortem predatory crab damage and ante- and postmortem mechanical damage in Mytilus trossulus shells, a combined field and experimental approach was used. Mussels were exposed to predation by crabs, tumbled-live, tumbled-dead, and trampled. After 100 h of tumbling, live-collected mussel shells were abraded and disarticulated but not otherwise damaged. Eight percent of the dead-collected shells were …