京都大学 / 新制・課程博士 / 博士(理学) / 甲第24126号 / 理博第4854号 / 新制||理||1694(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 本川 雅治, 准教授 中野 隆文, 教授 中務 真人 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

No description available.

Thesis (MA)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: At a social, ecological and biological level it is important tha t we gain a better understanding of species distribution and the constraints to species distribution. Various modelling tools and approaches are available to provide this type of functionality. The GARP (Genetic Algorithm for Rule set Production) Modelling System (GMS) was selected because of its strong predictive modelling abilities and its ability to represent the results of model iterations in both a tabular and cartographic manner. A shortcoming in this system was identified in tha t it requires strong information technology skills in order to carry out the modelling process. This can be attributed to the lack of a user-friendly interface to the system. In order to address this a loosely coupled system was developed that provides an easy to use web-based front end to the GMS. This Integrated Modelling System extends the core functionality of the GMS by providing a system that provides detailed history for each analysis, allows fine tuning of the modelling process, integrates directly with a biodiversity database containing specimen observations, and provides a simple ‘wizard’ interface to the modelling process. / AFRIKAANSE OPSOMMING: Van ’n sosiale, ekologiese en biologiese standpunt is dit belangrik dat ons spesies verspreiding en die beperkings daarvan verstaan. ’n Verskeidenheid sagteware pakkette en metodologiee is beskikbaar om spesies verspreiding te modelleer. Die GARP (Genetic Algorithm for Rule set Production) sagteware was gebruik vir sy sterk voorspellingsvermoe, en sy kapasiteit vir kartografiese en tubulere tentoonstelling van model resultate. ’n Tekortkoming met hierdie stelsel was gei'dentifiseer - dit is nie gebruikersvriendelik nie en gebruikers het sterk informasie tegnologie vermoens nodig. Om hierdie tekortkominge aan te spreek was ’n sagteware program ontwerp wat van GARP gebruik maak deur middel van ’n webblaaier. Hierdie ge'integreerde stelsel bou op die basiese funksionaliteit van GARP om ’n werk omgewing te skep wat ’n gedetailleerde geskiedenis van elke model stoor, fyn beheer oor die model toelaat, direk met ’n bio diver siteits databasis koppel, en van ’n eenvoudige ’wizard’ stelsel gebruik maak om gebruikers opsies te bepaal.

The Earth's most extensive living space is found in the bathypelagic zone of the oceans, yet research in these areas is scant. The micronekton of the bathypelagic zone in the eastern Gulf of Mexico (EGOM) was investigated with the goals of comparing its community structure and trophic interactions with those of the well-studied overlying mesopelagic micronekton. Significant changes in faunal structure were found, including shifts in dominant families as well as species. Compared to the mesopelagic zone, the bathypelagic community had increased abundance and biomass contributions from the Gonostomatidae, Oplophoridae,and Eucopiidae, with a simultaneous decrease in the importance of the Myctophidae and the Dendrobranchiata. The changed faunal structure within the crustacean assemblage includes a distinct difference in reproductive strategies. There is increased prevalence of taxa which feature egg brooding and abbreviated larval development. In addition, the bathypelagic zon e was characterized by relatively large biomass contributions from rare but large species, particularly those within the families Oplophoridae and Nemichthyidae. The faunal shifts, in combination with a high percentage of bathypelagic species absent from mesopelagic samples (~50% of crustacean and ~37% of fish species), suggest the bathypelagic zone is home to a distinct pelagic community, with a biology and ecology fundamentally different from that of the mesopelagic zone. The broad zoogeographic distributions of bathypelagic species suggest the EGOM assemblage is possibly similar to that of other geographic locations at similar latitudes. Diet analysis was performed on several prominent species and revealed 2 major feeding strategies based on diet composition and prey size. Species of Cyclothone and Eucopia preyedon small planktonic crustaceans, while the decapods examined were primarily piscivorous. The fraction of fish in the diets of decapods was greater than in their mesopelagic counterparts. It is suggested the primary trophic players in the system are oplophorid shrimps, followed by Cyclothone spp.

Distributional data from 32 years of aerial surveys of southern right whales (Eubalaena australis) along the south coast of South Africa were investigated using GIS, over a variety of spatial and temporal scales to test whether their discontinuous yet predictable distribution is related to environmental characteristics. Most whales were found in areas that provided reasonable protection from open ocean swell and seasonal winds as well as having sedimentary floors with gentle slopes, despite these characteristics being less common. Correlation type analyses with whale density only showed significance at the broadest scale. Cow-calf pairs were found significantly closer to shore and in shallower water than unaccompanied whales; they also segregated longshore in nursery areas. No relationship between reproductive success and distribution was found except a higher than expected incidence of neonatal strandings in areas dominated by unaccompanied whales. Habitat choice at this time of year was concluded to be related both to energy conservation for calves and lactating females and protection of neonates. / Dissertation (MSc (Zoology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

Peripheral capture locations have been used traditionally for predicting biological range limits. Maps based on these data may be inaccurate and may not provide useful information regarding the ranges of endangered species. A method was presented for predicting probable ranges of mammals based on the distribution of environmental factors associated with areas where animals have been known to occur. These factors were determined primarily from the literature. They were assigned relative weights based on frequency of occurrence in the literature. Computer technology was used to analyze an existing database stored at a cellular level to describe the probable distribution of the factors over large areas. Geomorphological, topographic, land-use, and physiographic data were included in the analyses. The method was applied to three mammals endangered in Virginia -- water shrew (Sorex palustris), northern flying squirrel (Glaucomys sabrinus), and Indiana bat (Myotis sodalis). Computer maps were produced showing the distribution of areas potentially favorable to each species in one of two study areas in Virginia. Maps produced by this method provide more information about ranges and range dynamics than tbos€ produced by traditional methods. Specifically, areas least likely to be favorable are shown as are those more likely to provide conditions suitable to the continued existence of the animal. Maps produced by this method may be useful for initial identification of critical areas, preliminary planning activities, endangered species management generally, and multiple range analyses. The method may be useful for range analyses of non-endangered species whenever information about range dynamics is needed. / Master of Science

The land snail genus Helix comprises large gastropods distributed in from France to Iran and in North Africa. Some of them have close linkage to humans - are synanthropic or are collected and consumed. The genus is most diverse in eastern Mediterranean. Taxonomy of the genus is now being revised from morphological point of view, and a molecular study is needed as a counterpart to that study. Here I present first phylogenetic data for the genus Helix, including almost all currently recognised species. I have used samples from various sources including dried bodies and tissue remnants. I have sequenced two commonly used mitochondrial markers (16S, COI). Position of the genus within Helicidae cannot be inferred from the dataset. The genus should be delimited in a strict sense, excluding genera Maltzanella, Cantareus, Cryptomphalus and Lindholmia. Division into subgenera, as proposed by various authors until now, is not supported with the exception of a split between subgenera Pelasga and the nominotypical Helix. Relationships between species and their groups are poorly resolved. Regarding species limits, the data are largely in agreement with new opinions based on morphology. There might be surprisingly high variability in shell characters within a species, as few morphologically characteristic taxa seem to be...

<p>Doktorska&nbsp; disertacija&nbsp; predstavlja&nbsp; studiju&nbsp; faune paukova (Arachnida, Araneae) Makedonije baziranu na&nbsp; kritičkoj&nbsp; analizi&nbsp; publikovanih&nbsp; podataka&nbsp; koji obuhvataju&nbsp; period&nbsp; od&nbsp; 1907.&nbsp; do&nbsp; 2018.&nbsp; godine, taksonomskoj reviziji relevantnih arahnolo&scaron;kih zbirki iz osam evropskih prirodnjačkih muzeja i rezultatima sopstvenih tridesetogodi&scaron;njih istraživanja. Terenski&nbsp; rad&nbsp; je&nbsp; baziran&nbsp; na&nbsp; sakupljanju&nbsp; materijala<br />kori&scaron;ćenjem&nbsp; standardnih&nbsp; metoda&nbsp; kao&nbsp; &scaron;to&nbsp; su&nbsp; ručno sakupljanje&nbsp; i&nbsp; sakupljanje&nbsp; putem&nbsp; klopki&nbsp; i&nbsp; noviju metodu&nbsp; upotrebom motornog&nbsp; usisivača. Materijal je<br />laboratorijski obrađivan standardnim postupcima uz pomoć binokularne lupe i mikroskopa. Ukupno&nbsp; su&nbsp; registrovane&nbsp; 742&nbsp; vrste&nbsp; paukova&nbsp; iz&nbsp; 40 familija.&nbsp; Pet&nbsp; taksona&nbsp; pretstavljaju&nbsp; nove&nbsp; vrste&nbsp; za nauku. Dve vrste predstavljaju nove&nbsp; nalaze za&nbsp; faunu paukova&nbsp; Balkanskog&nbsp; poluostrva.&nbsp; &Scaron;ezdeset&nbsp; i&nbsp; dva taksona&nbsp; su&nbsp; po&nbsp; prvi&nbsp; put&nbsp; zabeležene&nbsp; za&nbsp; faunu Makedonije. Drevna familija Anapidae je sa jednom vrstom po prvi put registrovana u fauni Makedonije. Revizijom publikovanih podataka, ustanovljeno je da je179&nbsp; vrsta&nbsp; pogre&scaron;no&nbsp; identifikovano&nbsp; i&nbsp; navedeno&nbsp; za<br />faunu Makedonije. Vrste&nbsp; su&nbsp; kategorisane&nbsp; prema&nbsp; trenutnom&nbsp; poznavanju njihove rasprostranjenosti, na osnovu čega je izvr&scaron;ena zoogeografska&nbsp; analiza&nbsp; faune.&nbsp; Ustanovljena&nbsp; su&nbsp; 32 horotipa&nbsp; u&nbsp; fauni&nbsp; paukova&nbsp; Makedonije,&nbsp; svrstana&nbsp; u četiri&nbsp; horolo&scaron;ka&nbsp; kompleksa:&nbsp; &scaron;ire&nbsp; rasprostranjene, evropske, mediteranske i endemske vrste. Najveći broj vrsta registrovano je u kompleksu &scaron;iroko rasprostranjenih&nbsp; vrsta&nbsp; (44,3%)&nbsp; koji&nbsp; daju&nbsp; glavni karakter fauni. Visok stepen zastupljenosti evropskih (19,1%)&nbsp; i&nbsp; eurosibirskih&nbsp; (11,3%)&nbsp; horolo&scaron;kih elemenata,&nbsp; kao&nbsp; dva&nbsp; pojedinačno&nbsp; najzastupljenija&nbsp; u fauni&nbsp; paukova&nbsp; Makedonije,&nbsp; je&nbsp; odraz&nbsp; dominantnog planinskog&nbsp; karaktera&nbsp; reljefa&nbsp; Makedonije.&nbsp; Horolo&scaron;ki kompleks&nbsp; mediteranskih&nbsp; vrsta&nbsp; zastupljen&nbsp; je&nbsp; sa&nbsp; 99 vrsta&nbsp; (13,3%).&nbsp; Visok&nbsp; udeo&nbsp; vrsta&nbsp; (11,3%)&nbsp; koje pripadaju horolo&scaron;kim elementima koji su zastupljeni na prostorima Južne Evrope, Mediterana, Zapadne i<br />Srednje&nbsp; Azije&nbsp; govori&nbsp; o&nbsp; bogatoj&nbsp; fauni&nbsp; paukova kserofilnih,&nbsp; termofilnih&nbsp; i&nbsp; aridnih&nbsp; terena.&nbsp; Lokalni karakter faune može se sagledati u relativno velikom broja&nbsp; vrsta&nbsp; iz&nbsp; kompleksa&nbsp; endemskih&nbsp; vrsta&nbsp; (87).&nbsp; Iz ovog kompleksa najdominantniji su vrste iz horotipa &quot;endemiti užeg područja&quot; sa 45 vrsta.Doktorska&nbsp; disertacija&nbsp; predstavlja&nbsp; studiju&nbsp; faune paukova (Arachnida, Araneae) Makedonije baziranu na&nbsp; kritičkoj&nbsp; analizi&nbsp; publikovanih&nbsp; podataka&nbsp; koji obuhvataju&nbsp; period&nbsp; od&nbsp; 1907.&nbsp; do&nbsp; 2018.&nbsp; godine,<br />taksonomskoj reviziji relevantnih arahnolo&scaron;kih zbirki iz osam evropskih prirodnjačkih muzeja i rezultatima sopstvenih tridesetogodi&scaron;njih istraživanja.Terenski&nbsp; rad&nbsp; je&nbsp; baziran&nbsp; na&nbsp; sakupljanju&nbsp; materijala kori&scaron;ćenjem&nbsp; standardnih&nbsp; metoda&nbsp; kao&nbsp; &scaron;to&nbsp; su&nbsp; ručno sakupljanje&nbsp; i&nbsp; sakupljanje&nbsp; putem&nbsp; klopki&nbsp; i&nbsp; noviju metodu&nbsp; upotrebom motornog&nbsp; usisivača. Materijal je laboratorijski obrađivan standardnim postupcima uz pomoć binokularne lupe i mikroskopa. Ukupno&nbsp; su&nbsp; registrovane&nbsp; 742&nbsp; vrste&nbsp; paukova&nbsp; iz&nbsp; 40<br />familija.&nbsp; Pet&nbsp; taksona&nbsp; pretstavljaju&nbsp; nove&nbsp; vrste&nbsp; za nauku. Dve vrste predstavljaju nove&nbsp; nalaze za&nbsp; faunu paukova&nbsp; Balkanskog&nbsp; poluostrva.&nbsp; &Scaron;ezdeset&nbsp; i&nbsp; dva taksona&nbsp; su&nbsp; po&nbsp; prvi&nbsp; put&nbsp; zabeležene&nbsp; za&nbsp; faunu Makedonije. Drevna familija Anapidae je sa jednom vrstom po prvi put registrovana u fauni Makedonije. Revizijom publikovanih podataka, ustanovljeno je da je179&nbsp; vrsta&nbsp; pogre&scaron;no&nbsp; identifikovano&nbsp; i&nbsp; navedeno&nbsp; za<br />faunu Makedonije. Vrste&nbsp; su&nbsp; kategorisane&nbsp; prema&nbsp; trenutnom&nbsp; poznavanju njihove rasprostranjenosti, na osnovu čega je izvr&scaron;ena zoogeografska&nbsp; analiza&nbsp; faune.&nbsp; Ustanovljena&nbsp; su&nbsp; 32 horotipa&nbsp; u&nbsp; fauni&nbsp; paukova&nbsp; Makedonije,&nbsp; svrstana&nbsp; u četiri&nbsp; horolo&scaron;ka&nbsp; kompleksa:&nbsp; &scaron;ire&nbsp; rasprostranjene, evropske, mediteranske i endemske vrste. Najveći broj vrsta registrovano je u kompleksu &scaron;iroko rasprostranjenih&nbsp; vrsta&nbsp; (44,3%)&nbsp; koji&nbsp; daju&nbsp; glavni karakter fauni. Visok stepen zastupljenosti evropskih (19,1%)&nbsp; i&nbsp; eurosibirskih&nbsp; (11,3%)&nbsp; horolo&scaron;kih elemenata,&nbsp; kao&nbsp; dva&nbsp; pojedinačno&nbsp; najzastupljenija&nbsp; u fauni&nbsp; paukova&nbsp; Makedonije,&nbsp; je&nbsp; odraz&nbsp; dominantnog planinskog&nbsp; karaktera&nbsp; reljefa&nbsp; Makedonije.&nbsp; Horolo&scaron;ki kompleks&nbsp; mediteranskih&nbsp; vrsta&nbsp; zastupljen&nbsp; je&nbsp; sa&nbsp; 99 vrsta&nbsp; (13,3%).&nbsp; Visok&nbsp; udeo&nbsp; vrsta&nbsp; (11,3%)&nbsp; koje pripadaju horolo&scaron;kim elementima koji su zastupljeni na prostorima Južne Evrope, Mediterana, Zapadne i<br />Srednje&nbsp; Azije&nbsp; govori&nbsp; o&nbsp; bogatoj&nbsp; fauni&nbsp; paukova kserofilnih,&nbsp; termofilnih&nbsp; i&nbsp; aridnih&nbsp; terena.&nbsp; Lokalni karakter faune može se sagledati u relativno velikom broja&nbsp; vrsta&nbsp; iz&nbsp; kompleksa&nbsp; endemskih&nbsp; vrsta&nbsp; (87).&nbsp; Iz ovog kompleksa najdominantniji su vrste iz horotipa &quot;endemiti užeg područja&quot; sa 45 vrsta.</p> / <p>The PhD research project is a study of fauna of spiders (Arachnida,&nbsp; Araneae)&nbsp; of&nbsp; Macedonia&nbsp; based&nbsp; on&nbsp; a critical analysis of published data covering the period from &nbsp; 1907&nbsp; to&nbsp; 2018,&nbsp; taxonomic&nbsp; review&nbsp; of&nbsp; relevant arachnological&nbsp; collections&nbsp; from&nbsp; eight&nbsp; European Natural history museums and the results of author&rsquo;s thirty years of research. Field&nbsp; work&nbsp; is&nbsp; based&nbsp; on&nbsp; the&nbsp; collection&nbsp; of&nbsp; materials using standard methods such as manual collection and trapping and a newer method using a motor&nbsp; vacuum cleaner.&nbsp; The&nbsp; material&nbsp; was&nbsp; processed&nbsp; with&nbsp; standard procedures&nbsp; using&nbsp; a&nbsp; dissecting&nbsp; binocular&nbsp; and&nbsp; a microscope.A total of 742 species of spiders from 40 families have been registered. Five taxa are new species for science. Two species present new findings for the fauna of the spiders of the Balkan Peninsula. Sixty&nbsp; two taxa were recorded for the first time&nbsp; for the fauna of Macedonia.An&nbsp; ancient&nbsp; family&nbsp; Anapidae&nbsp; with&nbsp; one&nbsp; species&nbsp; has been&nbsp; registered&nbsp; for&nbsp; the&nbsp; first&nbsp; time&nbsp; in&nbsp; the&nbsp; fauna&nbsp; of Macedonia. By reviewing&nbsp; the&nbsp; published data, it was established&nbsp; that&nbsp; 179&nbsp; species&nbsp; were&nbsp; incorrectly identified&nbsp; and&nbsp; listed&nbsp; for&nbsp; the&nbsp; fauna&nbsp; of&nbsp; Macedonia. Species&nbsp; are&nbsp; categorized&nbsp; according&nbsp; to&nbsp; the&nbsp; current knowledge of their distribution, on the basis of which a zoogeographic analysis of the fauna was performed.32&nbsp; chorotypes&nbsp; were&nbsp; established&nbsp; in&nbsp; the&nbsp; fauna&nbsp; of&nbsp; the spiders&nbsp; of&nbsp; Macedonia,&nbsp; classified&nbsp; into&nbsp; four chorological&nbsp; complexes:&nbsp; widespread,&nbsp; European, Mediterranean and endemic species. The&nbsp; largest&nbsp; number&nbsp; of&nbsp; species&nbsp; is&nbsp; registered&nbsp; in&nbsp; the complex of widespread species (44.3%), which give the main character of the fauna. The high degree of representation of European (19.1%) and Eurosiberian (11.3%)&nbsp; chorological&nbsp; elements,&nbsp; as&nbsp; the&nbsp; two individually&nbsp; most&nbsp; represented&nbsp; in&nbsp; the&nbsp; fauna&nbsp; of&nbsp; the spiders of Macedonia, is a reflection of the dominant mountain&nbsp; character&nbsp; of&nbsp; the&nbsp; relief&nbsp; of&nbsp; Macedonia.&nbsp; The chorological&nbsp; complex&nbsp; of&nbsp; Mediterranean&nbsp; species&nbsp; is represented&nbsp; by&nbsp; 99&nbsp; species&nbsp; (13.3%).&nbsp; The&nbsp; high proportion&nbsp; of&nbsp; species&nbsp; (11.3%)&nbsp; belonging&nbsp; to&nbsp; the chorological elements that are present on the territory of&nbsp; Southern&nbsp; Europe,&nbsp; the&nbsp; Mediterranean,&nbsp; West&nbsp; and Central&nbsp; Asia&nbsp; speaks&nbsp; of&nbsp; the&nbsp; rich&nbsp; fauna&nbsp; of&nbsp; spiders&nbsp; of&nbsp; xerophilic,&nbsp; thermophilic&nbsp; and&nbsp; arid&nbsp; terrain.&nbsp; The&nbsp; local character of the fauna can be seen in a relatively large number&nbsp; of&nbsp; species&nbsp; from&nbsp; the&nbsp; complex&nbsp; of&nbsp; endemic species&nbsp; (87).&nbsp; From&nbsp; this&nbsp; complex&nbsp; are&nbsp; the&nbsp; most dominant&nbsp; species&nbsp; from&nbsp;&nbsp; the&nbsp; chorotype&nbsp; &quot;narrower endemic&quot; with 45 species.Western&nbsp; Macedonia&nbsp; is&nbsp; the&nbsp; richest&nbsp; with&nbsp; fauna&nbsp; of spiders, with 23 species from the group of endemites of&nbsp; the&nbsp; narrower&nbsp; area,&nbsp; which&nbsp; speaks&nbsp; of&nbsp; the&nbsp; great importance of this region as a refugium and space in which&nbsp; the&nbsp; processes&nbsp; of&nbsp; speciation&nbsp; were&nbsp; intensively carried out.</p>

En la presente investigación, se estudió la estructura espacial de las asociaciones de peces demersales que forman parte de la captura incidental de la pesca de camarón, en el ecosistema costero del Golfo de Tehuantepec, en el Pacífico Oriental Tropical Mexicano. Los arrastres de pesca se llevaron a cabo en 11 campañas, durante la época de veda 2003, 2004 y 2005, en tres estratos de la plataforma continental (20, 40, 60 m). Para la determinación de las asociaciones, se utilizaron los valores de abundancia (individuos/ha) y las variables ambientales (temperatura, salinidad, sedimento, profundidad). Se aplicaron los análisis de clasificación nodal y el modelo de redundancia sin tendencia (RDA). Para determinar la influencia de los factores ambientales en la comunidad íctica, se estimaron las variaciones espaciales de los parámetros comunitarios diversidad, equitatividad, riqueza y dominancia, así como los indicadores agregados del estatus de la comunidad: curvas de dominancia-k, curvas ABC y espectro de tallas. En la comunidad de peces demersales del Golfo de Tehuantepec se han identificado 229 especies, 101 géneros y 51 familias. Las familias Haemulidae, Scianidae, Paralichthyidae, Gerreidae y Carangidae son las que predominan en los descartes del camarón, aportando más del 70% de la captura. Las especies Haemulopsis axillaris, Syacium ovale, Selene peruviana, Diapterus peruvianus, Larimus acclivins y Stellifer erycimba fueron más frecuentes en la plataforma interna y media, mientras que Prionotus stephanophrys, Scorpaena russula, Porichthys analis y Synodus scituliceps, fueron las especies dominantes en la plataforma externa (≥ 40m). Los valores más altos de biomasa se ubicaron entre los sistemas lagunares Huave y mar Muerto, presentando un gradiente de disminución con la profundidad. La mayor densidad y diversidad se registró frente a los sistemas lagunares Carretas-Pereyra y Chantuto-Panzacola. Los resultados indican que el Golfo de Tehuantepec presenta cinco áreas de asociación (A1-A5), que son consistentemente distinguibles una de otras, tanto por características ambientales, como por la composición de las especies que las estructuran. Las asociaciones A3 y A5 se localizaron entre Salina Cruz y los sistemas Huave y Mar Muerto, la A1 y la A2, se ubicaron dentro de la plataforma interna y media, en la externa. La distribución de estas asociaciones está influenciada por los vientos tehuanos y eventos de surgencias que se registran regularmente en la época seca, que se caracterizan por bajas temperaturas, alta concentración de nutrientes, y predominancia de fondos arenosos con grava, en el estrato somero de la región norte del golfo. Las asociaciones A1, A2 y A4 se ubicaron entre los sistemas lagunares Mar Muerto y Chantuto-Panzacola, se caracterizaron por la influencia de las descargas continentales en la época de lluvias que afectan a las condiciones hidrológicas, lo que determina la presencia de fondos areno-lodosos, en aguas someras (<30 m). Aunque la composición de peces en las asociaciones presenta ligeras variaciones durante los cambios estacionales, estos cambios son temporales, lo que provee un grado de predictibilidad en las capturas. Los indicadores agregados de la comunidad señalan un alto nivel de perturbación, de modo que las comunidades tienden a estar dominadas progresivamente por individuos de pequeñas tallas. Se analizaron las afinidades eco-geográficas, arrojando 36,1 % de especies de amplia distribución, desde la provincia de Cortés a la provincia Panámica, un 27,3% de especies euritérmas, que se distribuyen desde la provincia de San Diego a la Panámica, y un 13,2% de especies de distribución restringida entre la provincia Mexicana y Panámica. / This research studied the fish communities that were present in the bycatches of the shrimp fisheries at the ecosystems of the Gulf of Tehuantepec, in the Tropical Eastern Pacific off Mexico. Sampling was performed with the same trawls used in the fishery, during the months when the fishing was closed seasons (from April to August). A total of 11 surveys were conducted at several depth, during 2003 to 2005. To determine fish assemblages, values of abundance (individuals/ha) and environmental variables (temperature, salinity, sediment type and depth) were used, applying the nodal analysis classification and detrended redundancy model. Sampling of the demersal community allowed identification of 229 species, 101 genera and 51 families of fish in the Gulf of Tehuantepec. Families Haemulidae, Scianidae, Paralichthyidae, Gerreidae and Carangidae were dominant in shrimp discards, contributing over 70% of the bycatch weight. Haemulopsis axillaris, Syacium ovale, Selene peruviana, Diapterus peruvianus, Stellifer erycimba and Larimus acclivins were the most frequent species in the inner and middle shelf, while Prionotus stephanophrys, Scorpaena russula, Porichthys analis and Synodus scituliceps were the dominant species on the external shelf. The highest values of biomass were found between the lagoon systems Huave and Mar Muerto, showing a gradient of decreasing biomass with depth. The highest abundance and diversity was recorded in front of the lagoon systems Carretas-Pereyra and Chantuto-Panzacola. The results of the fish community analysis indicated that the Gulf of Tehuantepec had five assemblage areas. The A3 and A5 associations were found between Huave and the Mar Muerto lagoon systems. The A1 A2 and A3 association was located within the inner and middle shelf. The distribution of these associations was probably affected by Tehuanos winds and upwelling events, both occurring regularly during the dry season and characterized by low temperatures and high nutrients in the sea water. The community aggregate indicators point to a high level of perturbation, which a trend of the community structure to be dominated by individuals of small sizes. Analysis of eco-geographical affinity gave 36,1% of species of wide distribution, 27,3% of eurythermal species and 13,2% of species with distribution restricted only to Mexico and Panama province.

The addition of dams into a riverine system causes a wide range of changes (i.e., sedimentation, erosion, thermal) to the river as well as to the fish assemblages of that river. Although there have been many studies documenting the changes that occur to the fish assemblages in the impounded river, there have been fewer studies examining the effects of a reservoir on the fish inhabiting the tributaries upstream of the impoundment. One possible impact of a reservoir could be to act as a barrier to fish migration between streams. To determine if reservoirs restrict migration, the genetic diversity of two species of darter, the rainbow darter Etheostoma caeruleum Storer and the Highland Rim darter Etheostoma kantuckeense Ceas and Page, was determined from populations inhabiting the Barren River Lake drainage basin. Between ten and twenty-six individuals of each species were collected from each of 6 sites. Three streams were directly connected to Barren River Lake and three streams were directly connected to Barren River upstream of the reservoir. Allelic variation at 3 microsatellite loci was analyzed to determine the degree to which each population is isolated. If the reservoir is restricting gene flow between populations, the populations in streams adjacent to Barren River Lake would be predicted to have lower allele diversity and heterozygosity than those adjacent to the Barren River. Consistently high levels of allelic diversity (total number of alleles, N), observed heterozygosity (Ho), and effective number of alleles (Ae) across both reservoir and river study sites led to the rejection of the hypothesis that the reservoir is acting as a genetic barrier to darters. M-ratios differed between species, with Etheostoma caeruleum exhibiting consistently higher M--ratios than Etheostoma kantuckeense. The low M- seen in E. kantuckeense could be due to small sample sizes (largest sample for this species showed the highest M-), and could also be due to small natural populations. With the exception of Salt Lick Creek, high allelic diversity was observed at most sites for E. kantuckeense. A low M- coupled with high allelic diversity in most E. kantuckeense populations, may indicate that all of the study populations are recovering from a bottleneck event. These results indicate Etheostoma kantuckeense is sensitive to changes in the environment. When conservation agencies assess fish populations in South Central Kentucky, it is advantageous to know which species are currently at risk, which species are sensitive to environmental changes, and which species or populations are recovering from events that were detrimental to their genetic diversity.