21 resultados para Revista La Pluma (1927-1931)
em Aquatic Commons
Resumo:
Entre las lagunas bonaerenses con pesca abundante del pejerrey, la de del Monte, en Guaminí, logró fama por su rendimiento extraordinario en determinados años, para luego decaer casi desapareciendo como fuente pesquera. En 1927 el gobierno provincial denunció el hecho de que "el pejerrey casi no crecía". Por esta causa, en ese año realicé estudios con tendencia a un planeamiento ecológico del problema pesquero y que repetí en 1928 cuando, según los pescadores, las condiciones de pesca eran más favorables. El hecho principal resultante es que, si bien el pejerrey de esa laguna no crecía más de 23 o 24 cm de longitud total, sus escamas exhibían 3 y 4 anillos, lo que indica otros tantos años de edad. Para esa edad, en otras lagunas el pejerrey es mucho más grande.
Resumo:
Charles M. Breder Jr. “hypothesis” diary is a deviation from the field diaries that form part of the Breder collection housed at the Arthur Vining Davis Library, Mote Marine Laboratory. There are no notes or observations from specific scientific expeditions in the document. Instead, the contents provide an insight into the early meticulous scientific thoughts of this biologist, and how he examines and develops these ideas. It is apparent that among Dr. Breder’s passions was his continual search for knowledge about questions that still besieged many scientists. Topics discussed include symmetry, origin of the atmosphere, origin of life, mechanical analogies of organisms, aquaria as an organism, astrobiology, entropy, evolution of species, and other topics. The diary was transcribed as part of the Coastal Estuarine Data/Document Rescue and Archeology effort for South Florida. (PDF contains 33 pages)
Resumo:
Until now observations on the temporal variation of size of freshwater copepods have not provided much information. Other observers only mention in passing this or that phenomenon from which it is possible to deduct termporal variations. In this study Cyclops strenuus s.l., a freshwater species of fairly wide distribution, is studied in two water bodies. The author studies the systematic, placing of inhabitants described as C. strenuus Fischer in both locations, their annual life cycle, and their annual size variations.
Resumo:
This is a short excerpt of the original paper giving the key to the identification of the naupliar instars of the genus Cyclops.
Resumo:
This is a short excerpt of the original paper giving the key to the identification of the naupliar instars of the genus Cyclops.
Resumo:
Morphological observations on the two types of Pseudospora are given. The two Pseudospora whic are described are Pseudospora eudorini and Pseudospora volvocis. The systematic classification of the genus Pseudospora is discussed.
Resumo:
Portunus pulchricristatus (Gordon, 1931) is a rare species, to date we have obtained only three specimens, two males and a berried female which can be easily identified with the help of existing descriptions and illustrations. Brief account of the Pakistan material is given below. One male specimen (measuring 11.0 mm in carapace length) has been deposited in the National Museum of Natural History, Leiden (Reg.No.D.42393) the other two specimens housed in the Marine Reference Collection and Resource Centre (MRCC Cat. No.BRAC.491). The abbreviations used are cl. for carapace length and cb. for carapace breadth.