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Sturgeons (Chondrostei: Acipenseriformes) display markedly disjunction distributions with a wide distribution in the northern hemisphere. Their unique benthic specializations and conserved morphology, evolutionary age, the variation in their basic diadromous life history, and the large public interest due to their near extinction or critically endangered status make sturgeons and paddlefishes interesting groups for molecular and cytogenetic studies. From altogether 27 acipenseriform species, seventeen species are supposed to be critically endangered, two species are classified as endangered, four species are vulnerable and other species are near threatened or in low-risk (IUCN Red list 2010). Sturgeons are characteristic by a relatively high number of chromosomes in cell nuclei and differences in ploidy levels. Sturgeons displayed a strong tendency for interspecific and inter-generic hybridization under altered environmental conditions as well as under conditions of artificial propagation. Almost 20 inter-specific sturgeon hybrids were described. The decrease of natural populations and tendencies leading to restocking may result in uncontrolled restocking, production of hybrid specimens (even with non-native species) and decrease of natural genetic diversity of species in their original distribution area. Identification of parental species of natural hybrids by modern methods of molecular biology is still not easy. Here, we attempt to briefly summarize the major aspects of sturgeon genetics and cytogenetics related to ploidy levels and interspecific hybridization.

Total of 29 sturgeons (two species; length 8-37 cm) originating from fish farms in northern Poland with a known KHV history in common carp or koi in the area were examined: 15 Russian sturgeons, Acipenser gueldenstaedtii, with clinical signs of a disease and 14 asymptomatic Atlantic sturgeons, A. oxyrinchus. The preliminary results were obtained using PCR. Those findings were subsequently confirmation by nested PCR. The latter procedure consists of sequence analysis of PCR products and direct detection of KHV infected cells in tissue materials by in-situ hybridization on nucleic acid level or indirect immunofluorescence on KHV protein level. KHV genome parts were found in nine Russian sturgeons and four Atlantic sturgeons. Therefore a viral diagnostics is highly recommended not only for sturgeons obtained from the environment but also for fertilized eggs, fry, and fish intended for re-stocking measurements of inland waters

Conservation biology has provided wildlife managers with a wealth of concepts and tools for use in conservation planning; among them is the surrogate species concept. Over the past 20 years, a growing body of empirical literature has demonstrated the limited effectiveness of surrogates as management tools, unless it is first established that the target species and surrogate will respond similarly to a given set of environmental conditions. Wildlife managers and policy makers have adopted the surrogate species concept, reflecting the limited information available on most species at risk of extirpation or extinction and constraints on resources available to support conservation efforts. We examined the use of surrogate species, in the form of cross-taxon response-indicator species (that is, one species from which data are used to guide management planning for another, distinct species) in the Sacramento-San foaquin Delta, California (U.S.A.). In that system there has been increasing reliance on surrogates in conservation planning for species listed under federal or state endangered species acts, although the agencies applying the surrogate species concept did not first validate that the surrogate and target species respond similarly to relevant environmental conditions. During the same period, conservation biologists demonstrated that the surrogate concept is generally unsupported by ecological theory and empirical evidence. Recently developed validation procedures may allow for the productive use of surrogates in conservation planning, but, used without validation, the surrogate species concept is not a reliable planning tool. La biologia de la conservación ha proporcionado a los manejadores de vida silvestre una amplia gama de conceptos y herramientas para la planificación de la conservación, entre ellos el concepto de especies sucedáneas. En los últimos 20 años, un creciente cuerpo de literatura empírica ha demostrado la efectividad limitada de los sucedaneos como herramientas de manejo, a menos queprimero se establezca que la especie bianco y la sucedanea responderan de manera similar a un conjunto determtnado de condiciones ambientales. Los manejadores de vida silvestre y los tomadores de decisiones han adoptado el concepto de especie sucedanea, reflejando la limitada informacion disponible sobre la mayoria de las especies en riesgo de extirpacion extincion las limitaciones en los recursos disponibles para financiar los esfuerzos de conservacion. Examinamos el uso de especies sucedâneas, en la forma de especies trans-taxon indicadoras de respuesta (esto es, una especie de la que se usan datospara guiar la planificacion del manejo de otra especie),en el Delta Sacramento-San Joaquin, California (E. U. A.). En ese sistema ha habido creciente confianza en los sucedáneos en la planificacion de la conservacion de especies enlistadas en las actas federales o estatales de especies en pligro.aunque las agenctas que aplican el concepto sucedánea primero no validan que la especie sucedánea y la especie bianco respondan similarmente a condiciones ambientales relevantes. Durante este mismo período, los biólogos de la conservación demostraron que el concepto de especie sucedánea generalmente no es sostenido por la teoria ecológica ni la evidencía emprica. Procedimientos de validacion desarrollados recientemente pueden permitir el uso productivo de sucedàneos en la planificación de la conservación, pero, utilizados sin validación, el concepto de especies sucedàneas no es una herramienta de planificación confiable.

The effects coelomic fluid removal method and de-adhesion substances (milk solution, starch suspension and urea-NaCl-tannic acid solutions) had on fertilization rates and hatching success and time of Siberian sturgeon, Acipenser baerii Brandt were compared. It was concluded that rinsing Siberian sturgeon eggs prior to fertilization is recommended when there is abundant and viscous coelomic fluid. De-adhesion with milk ensures the shortest and most synchronous hatching of Siberian sturgeon larvae

This Sturgeon Hatchery Manual includes the latest available scientific research findings and experiences and compiles advice given in earlier manuals and handbooks on sturgeon culture and reproduction practices. This document can be considered an update of the Sturgeon Breeding and Rearing Handbook (Chebanov, Galich and Chmyr, 2004), which was published in the Russian language. The Sturgeon Hatchery Manual was prepared in response to numerous requests for practical guidance on this subject from the Central Asian and Caucasus region to the Food and Agriculture Organization of the United Nations (FAO). This manual is targeted particularly at sturgeon farmers, sturgeon hatchery operators, hatchery technicians, and fisheries and aquaculture managers involved in sturgeon aquaculture development and the restocking and rehabilitation of sturgeon populations in the countries around the basins of the Black and Caspian seas. It aims to provide a practical handbook of modern sturgeon hatchery practices and management. The manual is available in the English, Russian and Turkish languages. The manual starts with a chapter on the taxonomy, biology, distribution and life histories of Azov-Black and Caspian Sea sturgeons. Subsequent chapters discuss the following aspects of sturgeon hatchery practices: hatchery design, collection and transportation of wild broodstock, broodstock management, spawning and gamete processing, fry and fingerling rearing, production of live feeds, the technology of artificial reproduction, ecological- morphological and ethological-physiological express estimation of larval and fingerling (fry) viability, release of fingerlings into natural waterbodies, the formation of domesticated broodstock, basic sanitation and fish health measures, tagging, and early sexing and maturity determination in live sturgeons using ultrasound techniques. The manual also contains an extensive list of references, a list of Acipenseriformes and numerous figures, photographs and tables to support the guidance given on the various hatchery practices

The parasitic relationship between the leech, Caspiobdella fadejewi, and the juvenile Atlantic sturgeon, Acipenser oxyrinchus is presented. The aim was to determine leech invasion intensity and extensity and describe parasite feeding location preferences on the ventral side of the snout and gill cavities. The prevalence of C. fadejewi occurrence was 37.3 percentage, at an intensity of one to eight leeches. It was confirmed that the intensity of leech occurrence was positively correlated with sturgeon total length. The host-searching mechanism is most probably based on positive phototaxis. This is the first record of C. fadajewi from A. oxyrinchus

The collecting eggs method from sturgeon using a catheter is described. A catheter made of artificial material is introduced through the urogenital opening into the body cavity of the female, and this permits opening the ovarian funnels. Next, exterior abdominal massage creates pressure that forces eggs into a collection receptacle. This method has been applied since 2004 to culture sturgeon fishes. The catheter method of collecting fish eggs can be an alternative method thanks to its low invasiveness and ease of application

The feeding habits of sterlet, Acipenser ruthenus L., in the mid section of the Danube (km 1676-1694) was described. The fish were caught in the summers of 1991 and 1992. The food composition of 85 sterlets (mean body length BL = 37.1 cm; body weight W = 540 g) was analyzed. Most of the fish analyzed (98.8 percentage) had full digestive tracts. Sterlet is considered to be a typical benthic feeder. The food analyzed contained insect larvae and pupae (Trichoptera, Chironomidae), amphipods (Corophium sp., Gammarus sp.), bivalves (Bivalvia), polychaetes (Annelida) and barbel, Barbus barbus (L.). The dominant food items in the digestive tracts were larval caddisflies (Trichoptera), Corophium (Amphipoda), and larval Chironomidae

Juvenile Atlantic sturgeon, Acipenser oxyrinchus Mitchill, obtained by artificially reproducing wild spawners caught in the St. John River in Canada have been stocked since 2006 into several rivers in Poland. The current study to assess the feeding of Atlantic sturgeon in the Drweca River in Poland is part of a larger project to restore the species to this region. Hatchery-reared eleven-month-old Atlantic sturgeon were recaptured 2 to 10 days after their release into the river. This study provides the first data on the diet of A. oxyrinchus in the fresh waters of Europe. In June 2008, the stomach contents of the juvenile Atlantic sturgeon that had been recaptured were collected using gastric lavage. Of the 70 sturgeon the Drweca River which were subjected to gastric lavage, 67 percentage of them had empty stomachs. The diet of juvenile Atlantic sturgeon consisted of nine taxa of prey. Primarily, sturgeon eat small, soft-bodied larval Oligochaetae and Chironomidae

The habitats and the movements of juvenile Atlantic sturgeon, Acipenser oxyrinchus oxyrinchus Mitchill, in the Wisloka River (Poland) were described. Radio telemetry methods were used to identify migration rates and the sites where sturgeon stopped during the day. In the 2009-2010 period, 25 juvenile sturgeon equipped with radio telemetry transmitters were released into the Wisloka; most of them left the river from two to seven days later. In 2009, the sturgeon covered from 0 to 45.3 km, while one year later in 2010 they covered from 0.1 to 54.1 km; the mean migration rates in these two years did not differ significantly statistically. The sturgeon migrated at a mean rate of 0.84 BL (standard body length) in one second in 2009 and at 0.94 BL in one second in 2010. No statistically significant dependence was noted between migration rate and the size of the sturgeon