Canal diggers in Panama, 1904 to 1928

Leonard Carpenter Panama Canal Collection. Publication: The Canal Diggers in Panama 1904 to 1928 [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida. (10 page document)

On the feeding of freshwater ostracods. [Translation of: Zoologicheskij zhurnal, 27(2), 1948, 125-136]

The present work appertains to a series of investigations in the field of trophodynamics of water bodies conducted by the department of hydrobiology ”Mosrybvtuza” under the leadership of Prof. Director N.S. Gaevska. Usually with quantitative collections of benthos ostracoda are hardly taken account of. But with the employment of special methods it is possible to be convinced that they are encountered in massive numbers. The role of ostracods in the nutrition of fish is recognised as important by many authors. On the question of the feeding of ostracods, in the literature there are only the fragmentary indications about the occurrence in the gut of ostracods of algae (diatoms, desmids) and detritus. The study of the feeding of ostracods was conducted both by the method of dissecting the guts of ostracods taken from natural waters, and by the method of feeding ostracods under laboratory conditions with a variety of food objects. Moreover, with a view to revision of obtained quantitative data, for determination of food requirements of ostracods the respiration method was applied.

Evidence of algae in the excrement of ducks. [Translation from: Hydrobiologia 1 22-27, 1948. ]

In the extremely severe winter of 1946-47 the surface of the Pfaffikersee (near Zurich) lay under an unbroken seal of ice for a full three months. The number of wild ducks resting in this location was estimated to be about 400. Six samples of excrements of ducks were microscopically analysed and fragments of algae were identified. These analyses allow the expert to specify with definite certainty the feeding areas under investigation of the studied birds.

The efficiency of plankton in the utilization of the sun radiation [Translation from: Briroda, 12, 29-35, 1948]

The efficiency of utilisation of the sun's radiation by natural communities has not been properly demonstrated with what so far has been obtained of reliable values, and it represents a great interest in many respects. A systematic study of the biotic balance of lakes was done in the course of a succession of summers starting in 1932, extensive material was obtained, which permitted to compute a value fear the utilisation of the sun's radiation by plankton in lakes, and to compare this with corresponding values for marine plankton and terrestrial vegetation.

The content of organic matter in some waters in the Moscow region [Translation from: C.R. Acad. Soc. URSS, 61, 293-296, 1948]

There is at the moment no direct method of determining the organic matter content of natural waters. In 1940/41 8 different water bodies in central Russia were studied and their organic matter identified. The author concludes that there is currently no easy method to determine organic matter in water. A number methods need to be applied.

East African Inland Fisheries Research Organization Annual Report for the year 1948

Introduction The laboratory at Jinja is being developed as a centre for hydro-biological research in East Africa, It has been built and is at present wholly financed from a grant from the Central Research allocation of the Colonial Development Fund. The building contains six laboratories in addition to a library, common room and general office. A maximum number of ten research workers could be given laboratory accommodation. However, shortage of living accommodation will limit the numbers who can work here for the next year or two.

A record of Probopyrus bithynis (Richardson, 1904) in Macrobrachium rosenbergii (De Man) from coastal Andhra Pradesh, India, with special reference to host-parasite relationship

An incidence of bopyrid isopod infestation was observed in giant freshwater prawn, Macrobrachium rosenbergii (de Man) juveniles (40-60 mm/0.9-1.5 g) in a scampi culture farm in East Godavari district of Andhra Pradesh. The presence of parasite was observed by conspicuous boil like swelling of the branchial chamber where the parasite was found lodged on the gills. The infested gill was highly compressed and necrosed. Only one branchial chamber was infested by the parasite while the other gill was normal. The infested prawns were thin and emaciated and showed retarded growth. The parasite was identified as Probopyrus bithynis (Richardson, 1904) which caused inhibition of ventilation due to its permanent lodging in the branchial chamber and impaired the gaseous exchange by gills. It was also observed that this parasite caused parasitic castration in the infested prawns.

Morphometrics, length-weight relationship and condition of Rastrineobola argentea (Pellegrin 1904) in the Winam Gulf of Lake Victoria (Kenya)

Correlation between total length (TL), fork length (FL) and standard length (SL) of Raslrineobola argentea (pellegrin 1904) in the Winam Gulf of Lake Victoria indicate that FL = 0.92 TL - 0.74 and SL = 0.90 TL - 1.74. Length-weight relationship of log-transformed data shows that the slopes of the regression lines were 3.06 to 3.22 for juveniles, 2.70 to 3.05 for males and 3.24 to 3.71 for females. The slopes were significantly different between groups at at a =0.05. The Fulton's condition factor (K) was highest in December (1.019-1.073) and March/April (1.015-1.030) but lowest in June (1:00-1.025) for all stations. Significant differences between groups demands for the use of different growth models for juveniles, males and females especially for the von Bertalanffy growth equation which uses length-weight relationship. Observed cyclic viations in condition factor suggests two peak breeding seasons for this species in the Winam Gulf. The practical lmplications of these results in stock assessment using length-based fish stock assessment methods is briefly discussed.