Major problems concerning the conservation and recovery of the Atlantic sturgeon Acipenser sturio L., 1758

Analysis of existing data and information show that the present status of the Atlantic sturgeon Acipenser sturio L., 1758, is much more complex than that of any other sturgeon worldwide. The name A. sturio includes 9-12 geographically, and probably also reproductively, isolated populations with disrupted gene flow. If so, and if there are both morphological and genome differences among them, then this name is used to designate several distinct species. Restoration programmes for the particular geographic area in which the Atlantic sturgeon has been known must be based on the stocking of offspring of the same genome from ancestors coming from the same geographic area. The stocking of specimens from other geographic areas would be similar to introduction of an exotic species sensu stricto, resulting in wide-ranging, unexpected and irreversible consequences. Therefore, the ultimate decision on such stocking has to be preceded by careful and scientifically sound analyses of the intended action. Any final solution to this problem needs close international co-operation and financial support from the countries concerned.El análisis de los datos e informaciones existentes muestra que el estado actual del esturión atlántico Acipenser sturio L., 1758 es mucho más complejo que el de cualquier otra especie de esturión en todo el mundo. El nombre A. sturio comprende 9-12 poblaciones geográficamente, y probablemente también reproductivamente, aisladas con una corriente interrumpida de genes. Si es realmente así, y entre estas poblaciones existen diferencias tanto morfológicas como genómicas, este nombre denomina entonces varias especies distintas. Los programas de recuperación para un área geográfica particular en la que A. sturio ha sido conocido tienen que estar basados en la repoblación con descendientes con idéntico genoma de ancestros procedentes de la misma región geográfica. La repoblación con ejemplares de una región geográfica diferente significaría la introducción de una especie exótica sensu stricto, resultando una ampliación de su rango, con consecuencias imprevistas e irreversibles. Por eso, la decisión final sobre tal repoblación tiene que basarse en un análisis cuidadoso y científicamente sólido de la acción proyectada. Cualquier solución final de este problema exige una estrecha colaboración internacional y también el apoyo económico de los países involucrados.Instituto Español de Oceanografí

Distribution of Acipenser sturio L., 1758 in the Black Sea and its watershed

The Atlantic sturgeon Acipenser sturio L., 1758, was always rare in the Black Sea, and the least numerous in comparison with other sturgeons. At the end of the 19th and the first half of the 20th centuries, it occurred along almost the entire Black Sea coast. It has been distributed predominantly in the eastern part of the Black Sea, especially in the region adjacent to Georgia's Inguri and Rioni rivers, with spawning grounds in the latter. It has also been recorded occasionally in the Danube River, where it occurred mostly in its delta. Earlier records even indicate its reproduction in the Danube. Recently its distribution and population density has been dramatically reduced. The distribution of this species is limited only to the eastern part of the Black Sea, and the recent total density of adults is estimated at only several hundred specimens. This situation has placed A. sturio on the list of critically endangered fish species. Existing data on its morphology and ecology indicate some differences between the Black Sea stock and populations from the Atlantic Ocean and the Baltic and Mediterranean Seas.El esturión atlántico Acipenser sturio L., 1758 siempre ha sido raro en el mar Negro, y el menos numeroso en comparación con otros esturiones. A finales del siglo XIX y primera mitad del XX se encontraba a lo largo de toda la costa del mar Negro. Se distribuía predominantemente en la parte oriental del mar Negro, en especial en la región adyacente a los ríos Inguri y Rioni en Georgia, con áreas de freza en este último. También ha sido citado ocasionalmente en el río Danubio, donde ocupaba sobre todo su delta. Las citas más antiguas incluso indican su reproducción en el Danubio. Recientemente su distribución y densidad de población se han visto dramáticamente reducidas. La distribución de esta especie se limita sólo a la parte oriental del mar Negro, y la densidad total reciente de adultos se estima en sólo algunos cientos de individuos. Esta situación ha colocado a A. sturio en la lista de especies de peces en peligro crítico. Los datos conocidos sobre su morfología y ecología indican algunas diferencias entre la población del mar Negro y las del océano Atlántico y los mares Báltico y Mediterráneo.Instituto Español de Oceanografí

Past and present distribution of Acipenser sturio L., 1758 in Russia, and problems involving its restoration

The Atlantic sturgeon Acipenser sturio L., 1758 has always been rare in Russia. Its main distribution was concentrated in the Gulf of Finland, from which it ascended the Neva River and entered Lake Ladoga and some of its tributaries. The landlocked population of this species was known in Lake Ladoga. In the 20th century, there are recorded catches of only 25 adult and 12 juvenile specimens. Since the last specimen was caught in 1985, the Atlantic sturgeon can be considered as extirpated in the water bodies of Russia. While recovery plans have been drawn up, the lack of living specimens is a serious obstacle to re-establishing this population.El esturión atlántico Acipenser sturio L., 1758 ha sido siempre raro en Rusia. Su distribución principal se concentraba en el golfo de Finlandia, desde donde ascendía por el río Neva y entraba en el lago Ladoga y en algunos de sus afluentes. Una población aislada de esta especie era conocida del lago Ladoga. En el siglo XX se recogen capturas de sólo 25 ejemplares adultos y 12 juveniles. Desde que el último ejemplar fue capturado en 1985, el esturión atlántico puede ser considerado como extinguido de las aguas de Rusia. Aunque los planes de recuperación han sido preparados, la falta de ejemplares vivos es un serio obstáculo para el restablecimiento de esta población.Instituto Español de Oceanografí

Identification of significant features in signals of equine cardiovascular system using ICA

The paper deals with application of the Independent Component Analysis (ICA) for looking for causes of the sudden cardiovascular death in horses during surgery. The first chapter describes the solved problem and state of art. Next part describes the ICA method and its properties and an input data format. In the third and fourth parts results of the analysis are presented. It was found that not all the three important components contained in the input data must be also part of the output data set. The most frequent case (6 records of 10) is that only two components were sufficient for description of input data

†Kenyaichthyidae fam. nov and †Kenyaichthys gen. nov - First Record of a Fossil Aplocheiloid Killifish (Teleostei, Cyprinodontiformes)

The extant Cyprinodontiformes (killifishes) with their two suborders Cyprinodontoidei and Aplocheiloidei represent a diverse and well-studied group of fishes. However, their fossil record is comparatively sparse and has so far yielded members of the Cyprinodontoidei only. Here we report on cyprinodontiform fossils from the upper Miocene Lukeino Formation in the Tugen Hills of the Central Rift Valley of Kenya, which represent the first fossil record of an aplocheiloid killifish. A total of 169 specimens - mostly extraordinarily well preserved and a sample of ten extant cyprinodontiform species were studied on the basis of morphometrics, meristics and osteology. A phylogenetic analysis using PAUP was also conducted for the fossils. Both the osteological data and the phylogenetic analysis provide strong evidence for the assignment of the fossils to the Aplocheiloidei, and justify the definition of the new family dagger Kenyaichthyidae, the new genus dagger Kenyaichthys and the new species dagger K. kipkechi sp. nov. The phylogenetic analysis unexpectedly places dagger Kenyaichthys gen. nov. in a sister relationship to the Rivulidae (a purely Neotropical group),a probable explanation might be lack of available synapomorphies for the Rivulidae, Nothobranchiidae and Aplocheilidae. The specimens of dagger K. kipkechi sp. nov. show several polymorphic characters and large overlap in meristic traits, which justifies their interpretation as a species flock in statu nascendi. Patterns of variation in neural and haemal spine dimensions in the caudal vertebrae of dagger Kenyaichthys gen. nov. and the extant species studied indicate that some previously suggested synapomorphies of the Cyprinodontoidei and Aplocheiloidei need to be revised

Explanation of some features of the cardiovascular control in horses

Shortening of RR intervals is often associated with prolonging QT intervals in dynamic studies of the cardiovascular activity in horses. Causes of the relationship have not been explained neither in veterinary nor human medicine yet. Our simulation experiments explain that the heart ventricle activity is controlled by at least two phenomena. One of them is stimulating and the other inhibiting. The identified values of the model parameters denote that the control effects are supposed to be both nervous and humoral

Linear feedback analysis of cardiovascular system using seismocardiogram

The paper deals with an analysis of relationship between heart rate described by a sequence of cardiac interbeat intervals and mechanical activity of heart represented by a sequence of systolic forces. Both the quantities were determined from seismocardiograms recorded from healthy subjects under two different experimental conditions. The method of the linear feedback baroreflex approach originally developed in [1], [2] and [3] was applied for the analysis. Different character of obtained results in comparison to those described in [1], [2] or [3], is explained by differences between frequency properties of the recorded sequences of the systolic forces and values of systolic blood pressure