The Rio Grande cichlid (Herichthys cyanoguttatus) has been established in the Greater New Orleans Metropolitan Area (GNOMA) for at least 20 years. It is often the most common fish species in urban canals and has also been found in natural waterways outside of the GNOMA. The effects and potential for further spread of H. cyanoguttatus is uncertain. My research addressed how extensive the cichlids spread in the GNOMA, how H. cyanoguttatus interacted with L. macrochirus, a native fish, and what salinity tolerance this species has. Surveys on Lake Pontchartrain and in the GNOMA indicated that H. cyanoguttatus is well established in urban habitats. These surveys also indicate that H. cyanoguttatus has spread rapidly into Bayou Saint John and City Park in recent years and that H. cyanoguttatus populations were relatively unaffected by Hurricanes Katrina and Rita. There is little evidence that H. cyanoguttatus has become established outside of the GNOMA, but this lack of persistence cannot be explained by abiotic variables I measured. Salinity may be a factor and this was measured in growth trials of H. cyanoguttatus. Salinities up to 16 ppt, however, had no significant effect on H. cyanoguttatus growth. Interspecific behavioral experiments were conducted to examine potential biotic interactions with native fish species. Prior resident trials indicated that H. cyanoguttatus was aggressive whether holding territory or not, and that native bluegill (Lepomis macrochirus) was only aggressive while holding territory. Feeding experiments were performed to examine biotic interactions between H. cyanoguttatus and L. macrochirus. Lepomis macrochirus grew faster than H. cyanoguttatus when inter- and intraspecific trials were compared; however, no significant growth differences were seen when trials were structured with L. macrochirus as prior residents. The major findings of my research are a high salinity tolerance of H. cyanoguttatus, a potential mechanism for H. cyanoguttatus affecting native fishes through aggression as residents and invaders, and the presence of H. cyanoguttatus throughout the GNOMA, before and after the hurricanes.

The brain has been one of the central foci in studies of vertebrate evolution. Work in East African cichlids and other emerging fish models like the Mexican cavefish (Astyanax mexicanus) offer new insight on the role of patterning on brain evolution. These fish can be grouped into two major categories according to habitat; for cichlids it is rock-dwelling (known locally as mbuna) and sand-dwelling (non-mbuna) lineage. The brain development of mbuna versus non-mbuna is defined by changes in gene deployment working along the dorsal/ventral (DV) and anterior/posterior (AP) neuraxes, respectively. Comparison of disparate fish ecotypes offer a new perspective of the role of patterning on brain evolution; through the slight and early modification of signal pathways working across 3-D axes, and a subsequent magnifying effect across ontogeny, evolution can generate widespread changes in the brain. To illustrate this patterning model of brain evolution, two comparative studies were done between mbuna and non-mbuna, examining the action of gene pathways that work to pattern the cichlid forebrain. The first study found that non-mbuna cichlids have a more rapid AP expansion of a gene pathway (Wingless) into the presumptive midbrain and diencephalon versus mbuna. These forebrain structures are involved in sight processing and could be of ecological benefit to vision-focused non-mbuna. The second study described a difference within the developing telencephalon. The embryonic telencephalon is split into the pallium, which processes visual signals, and the subpallium, which develops into the olfactory bulbs. Mbuna possess a larger subpallium relative to non-mbuna, which have a larger pallium. This was correlated to a more rapid expansion of another gene pathway (Hedgehog) along the DV axis. The difference in size of the pallial vs. subpallialial comparments between cichlids can be correlated to expanded olfaction in mbuna and vision in non-mbuna adult brains. Overall, East African cichlids are an excellent system to investigate the role of patterning on brain evolution because they allow for the comparison of the earliest patterning events in brain ontogeny between distinct ecotypes. These fish systems link study in brain development to the brain morphology comparisons employed in classic studies of brain evolution.

Historical biogeography of cichlid fishes within the Usumacinta province (Mexico, Guatemala, and Belize) is reviewed based on newly collected material specifically for this study. Five areas of endemism within the province were recognized using Parsimony analysis of endemicity. Dispersal-Vicariance analysis implemented in S-DIVA suggests only one of them (the Grijalva-Usumacinta) as the ancestral area for the whole fauna. Other areas of endemism within the Usumacinta province were colonized from this area by dispersals. This biogeographic interpretation suggests a long evolution of the richest cichlid fauna in Middle America in the Grijalva-Usumacinta area of endemism in a sympatric context.

Invasive species have caused billions of dollars in damages to their introduced environment through direct effects on wildlife and by altering their introduced habitats. For a species to be considered invasive, it must successfully navigate the stages of invasion: it must be introduced, become established, spread, and have a quantifiable impact on its introduced environment. The numbers of introductions and individuals released affects the genetic diversity of nonnative populations which, in turn, can affect their invasion success. The Mayan Cichlid (Cichlasoma urophthalmus) is endemic to the Atlantic coast of Mexico and Central America. It was first detected in the United States in 1983 in Everglades National Park. Since then, it has spread across more than 70,000 hectares throughout southern and central Florida. I have established the Mayan Cichlid to be a successful invader in Florida by quantifying per capita negative impacts of Mayan Cichlids on densities of Sheepshead Minnow (Cyprinodon variegatus), Marsh Killifish (Fundulus confluentus), and Eastern Mosquitofish (Gambusia holbrooki) over a 15-year period. I also analyzed the role of genetics in the invasion success of the Mayan Cichlid. I used a mitochondrial gene, cytochrome b, and 17 microsatellite loci to identify the sources for the Mayan Cichlid introduction into Florida. Cytochrome b data supported an introduction from Guatemala; microsatellite data suggested movement of Mayan Cichlids from the upper Yucatán Peninsula to Guatemala and introductions from Guatemala and Belize to Florida. I also found evidence of cytonuclear disequilibrium together with low genetic diversity within the Florida population which indicate a population bottleneck and admixture between two distinct lineages upon introduction, followed by rapid spread resulting in a panmictic population genetically distinct from the native range populations. I found much less genetic structure and a weaker correlation between genetic diversity and geographic distance within Florida compared with Mexico and Central America. Low number of effective alleles, heterozygosities, and FST values and the genetic similarity of Florida sites also indicate an admixed population or one that has rapidly expanded from a small initial group.

Jaguar Guapote (Parachromis managuensis) and Amphilophus spp. were assessed for effects of temperature on standard metabolic rate (SMR) and lower dissolved oxygen tolerance (LDOT), efficacy of gastric lavage for diet analysis, and diet in Puerto Rico reservoirs. Fish were acclimated to 22°C, 28°C, and 34°C and SMR and LDOT were measured using intermittent respirometers. Jaguar Guapote acclimated to 34°C had the greatest SMR, with 22°C and 28°C having similar SMR values. Amphilophus spp. acclimated to 28°C were similar to fish acclimated at 22°C and 34°C. Fish were resilient to high temperatures, losing equilibrium more rapidly at the coldest temperature, 22°C. Gastric lavage had low to moderate efficacy in extracting diet from cichlids. Diet in reservoirs differed among all species but overlap was present, suggesting cichlids in Puerto Rico may impact sportfish populations. These findings are important for making informed management decisions.

No description available.

Cerebral lateralization was once thought to be unique to humans, but is now known to be widespread among the vertebrates. Lateralization appears to confer cognitive advantages upon those that possess it. Despite the taxonomic ubiquity and described advantages of lateralization, substantial individual variation exists in all species. Individual variation in cerebral lateralization may be tied to individual variation in behaviour and the selective forces that act to maintain variation in behaviour may also act to maintain variation in lateralization. Sex differences may also be an important source of variation in lateralization, as differences between males and females are often observed. Here, I present three papers that collectively deal with the interrelationships between sex, behaviour and cerebral lateralization in the convict cichlid. My results illustrate that lateralization is related to personality-like characteristics in the convict cichlid, and that there are important differences between the sexes in their pattern of lateralization.

I concern on african mouthbrooding fishes (Cichlidae) and the possible role of egg-dummies during their courtship (Wickler's theory). I am bringing list of african cichlid fishes with information about kind of parental care, courtship ritual and presence of egg-dummies and I am giving this ethoecological information to phylogenetic context.

No description available.

No description available.