H. zebra und REPAPAq

[Baron Ätzmolch]

Zitat von Baron Ätzmolch

Im Rahmen der oben erwähnten Projekte bzw. wissenschaftlichen Forschungsarbeiten zu H. zebra wird es auch zwei Magisterarbeiten an der Universität des brasilianischen Bundesstaates Para geben, die gerade in Arbeit sind:

Ana Paula Oliveira Roman
Biologia reprodutiva e dinâmica populacional de Hypancistrus zebra Isbrücker & Nijssen, 1991 (Siluriformes, Loricariidae) no rio Xingu, amazônia brasileira / Ana Paula Oliveira Roman; orientadora, Victoria Isaac; co-orientadora, Rossineide Rocha. – 2011.

Dissertação (Mestrado) – Universidade Federal do Pará, Instituto de Ciências Biológicas, Programa de Pós-Graduação, em Ecologia Aquática e Pesca, Belém, 2011.

https://www3.ufpa.br/ppgeap/images/s...O_%20Roman.pdf


Abstract:
Hypancistrus zebra is a specie used with ornamental purposes, endemic and rare in the Middle - Lower Rio Xingu, which has strong demand from the international ornamental fish market, which created a strong pressure of exploitation associated with this species. H.zebra is included on the list of Brazilian fauna threatened with extinction and their capture is prohibited. It is known that even prohibited, it continues to be captured and exported illegally, together with the construction of this hydroelectric Belo Monte in his patch of distribution, which threatens their geographical distribution and lack of information on its biology and ecology make it difficult planning actions for this species. So, if this work aimed to study aspects of reproductive biology and population dynamics to contribute to conservation measures for this species.
Specimens of H. zebra were taken monthly from March 2009 to February 2010, by diving with a compressor, on the Xingu River, between the location of the weevil and Rita village of Belo Monte. The captured individuals were weighed and measured (total weight and total length). The gonads were removed and immediately fixed in Bouin solution. This was followed by routine histological techniques and the slides were stained with hematoxylin-eosin (HE). The stages of gonadal maturation were described based on the presence of germ cells at different stages of development. Through the length frequency data, estimates of population parameters such as growth models, recruitment, mortality, yield per recruit and size of first gonadal maturity. The species showed a seasonal spawning peaks between the two transition seasons of drought and flood (and vice versa) of the river, and two periods of recruitment, with different growth rates. It was estimated that the species has a lifespan of five years, and is at the limit of maximum sustainable yield, which is characterized as a dangerous situation for the species, because any increase in effort will compromise the stock and it is not known impacts that occur as a result of changes in their habitat caused by dam construction.
Key-words: Loricariidae, Xingu River, reproduction, population dynamic

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Was für ein Gestammel. Liest sich, als wär' es mit einem elektronischen Helferlein übersetzt worden.

Mädchen, Mädchen, ich kann doch sowas in einer wissenschaftlichen Arbeit nicht bringen.

[Baron Ätzmolch]

Dissertação: "Ecologia e etnoecologia de Hypancistrus zebra (Siluriformes: Loricariidae) no rio Xingu, Amazônia brasileira"
Autora: Alany Pedrosa Gonçalves

https://www.ufpa.br/ppgeap/images/st...20a%202011.pdf


Abstract:
H. Zebra is a fish species of the Loricariidae family, Ancistrinae subfamily, endemic of the Xingu River, with distribution from Belo Monte to the confluence of the Xingu and Iriri rivers. Being a species with great market value aquarist ornamental his capture became rampant, making it an endangered species. Despite strong pressure on H.zebra, there are still few studies on the species. Thus, given the scarcity of basic information and the constant threats, knowing the biology and ecology of H. zebra, aggregating the results of scientific research, also the local ecological knowledge of fishermen ornamental trade about this species becomes an essential tool for the conservation of the species. The distribution of H. zebra is restricted to a small stretch of the Xingu River, between Gorgulho da Rita and Itaubinha, and does not occur evenly, it depends on the presence of boulders. A total of 283 individuals of H. zebra were visualized in the rocky outcrops of the study area, of which 232 were captured. The lowest average abundance was Gorgulho da Rita, as opposed to the site Jericoá with the greatest abundance. Between periods, there was a greater abundance in dry river and lowest value for the period of filling. Environmental factors had no significant influence on the abundance of H. zebra. H. zebra is a generalist species, feeding mainly of periphytic algae, debris, plant debris and sponges, while nematodes and millipedes were considered occasional items. Diet composition and abundance of H. zebra showed no significant differences for collection sites, periods of the year and ontogeny. Considering the composition and abundance of the diet, H. zebra can be considered an iliophagous-omnivorous, and ability to adapt changes in food availability in the construction of the Hidroeletric Belo Monte. Ornamental trade fishermen demonstrate expert knowledge concerning the distribution and abundance, habitat, feeding, predation and reproduction of the H. zebra, which can be used to optimize work and to facilitate future management measures. The construction of the Hydroeltric Belo Monte Hydroelectric is a threat to the survival of H. zebra and future studies and monitoring of the species are needed, either as mitigation of impacts, either as to captive breeding as an alternative income coastal communities who depend on fishing on the Xingu river ornamental.