New gastropods from East Pacific hydrothermal vents

The following new prosobranch species are described: Cyuthermia (gen.n.) naticoides, Lucunoidc (gen.n.) exquisitus (Neomphalidae); Peltospira Iamellifera, Pachydermia (gen.n.) laevis, Depressigyra (gen. n.) g1obulus. D. plunispira, Solutigyra (gen. n.) reticulata, Lirapex (gen. n.) humata, L. granularis (Peltospiridae); Bathymargarites (gen.n.) symplector (Trochidae) and Provanna mucleani (Littorinoidea). Shells and soft parts of the species are described and figured. One species each of Sinezona (Scissurellidae), Moel1rriopsis (Seguenzoidea) and Phymorrhynchus (Turridae) is recorded from East Pacific hydrothermal vents, but not identified to species. Information about feeding biology and type of larval development is given for most of these species. The systematic position of the new species of Neomphalidae and Peltospiridae is considered uncertain, but further anatomical investigations are in progress. The gastropod fauna of East Pacific sulphide-rich environments is summarized and composition, endemism, age. dispersal, predation, adaptations and feeding biology are discussed.     

Toward better scientific presentation

Day, Robert A. 1979: How to Write and Publish a Scientific-Paper. 160 pp. ISI Press, Philadelphia. ISBN 0 894950088 (cloth), ISBN 0894950061 (paperback). Price USD 15.00 and 8.95, respectively.
Cremmins, Edward T. 1982: The Art of Abstracting. 145 pp. ISI Press, Philadelphia. ISBN 0894950150. Price USD 13.95 (paperback).
Barnes, Gregory A. 1982: Communication Skills for the Foreign-Born Professional. ISI Press, Philadelphia. ISBN 0894950134 (cloth). ISBN 0894950142 (paperback). Price USD 18.95 and 13.95, respectively.     

Effects of benthivorous fish on biogeochemical processes in lake sediments

1. Studies of aquatic environments have shown that community organisation may strongly affect ecosystem functioning. One common phenomenon is a change in nutrient level following a shift in the fish community composition. Although several hypotheses have been suggested, there is no consensus on which mechanisms are involved. Our study evaluated indirect effects of benthivorous fish on the biogeochemical processes at the sediment–water interface separately from direct effects caused by nutrient excretion or sediment resuspension. 2. We assigned field enclosures to three treatments representing typical pond communities; without fish, addition of approximately 10 small tench or addition of one large bream. After one summer, we monitored the water chemistry, benthic invertebrates and periphyton in the enclosures and sampled sediment cores for laboratory analysis of biochemical process rates (oxygen, phosphorus and nitrogen exchange between sediment and water, and denitrification rate). 3. Fish had strong negative effects on benthic invertebrates, but weaker effects on periphyton, organic content and porosity of the sediment. Moreover, there were significant positive fish effects on both phosphorus and nitrogen concentrations in the water. However, there were no general treatment effects on sediment processes that could explain the treatment effects on water chemistry in the enclosures. 4. Hence, overall treatment effects attenuated along the chain of interactions. We conclude that the observed effect of benthic fish on water chemistry was probably because of direct effects on nutrient excretion or resuspension of sediment. The similarity between bream and tench treatments suggests large niche complementarity despite their different habitat preferences.     

Editor's column: Symposia and congresses

Symposia and congresses (and similarly named conferences) provide a specific medium for scientific communication that should complement, not duplicate, published or circularized reporting. The total expenditure for presentation of results at a session of the International Geological Congress is at least in the region of 8 million dollars, and there are hundreds of smaller geological meetings every year. Progress in finding rational forms for meetings is slow, and elementary deficiencies in meeting organization are incessantly repeated. The fact that meetings have established themselves as a very viable institution in science provides no excuse for not watching and reviewing their structure and economy as vigilantly as, for example, publications.     

BULINUS AFRICANUS-GROUP SPECIES IN WEST AFRICA DIFFERENTIATED BY MORPHOMETRIC ANALYSIS (GASTROPODA, PLANORBIDAE)

In the present study 241 shells from snails belonging to theBulinus africanus-group in West Africa, were examined in a morphometricanalysis including ten characters. Principal component analysisand stepwise discriminant function analysis were used for analysisof the data. It was shown that Bulinus umbilicatus, B. jousseaumeiand B. globosus are clearly distinct on morphometric shell characters.Besides a general differentiation between the three species,the characters necessary for differentiation between them twoby two are found. The knowledge of the geographic distributionof B. umbilicatus and B. jousseaumei is significantly improved. (Received 18 March 1988; accepted 4 May 1988)     

Editor's column: Stratification in international geology

The two large organizations in international geology, the permanent International Union of Geological Sciences (IUGS) and the long-term International Geological Correlation Programme (IGCP), are strongly stratified units and victims of platform sedimentation. Their National Committees and corresponding bodies are often useless as channels of the active scientists' initiative and influence. Their constituent and affiliated scientific bodies are deprived of all influence on the management of the organizations, in favour of managements bureaucratically and autocratically recruited according to a pattern of equitable geographical distribution. The IGCP is wasting effort in hunting for programme gaps, whilst both organizations are campaigning against regional concentrations of interest and consequent influence. Both organizations are in bad need of activating their national members and opening up their management to influence from their scientific bodies. For this purpose important changes in their constitutions are needed. Only then can their formal strength become real and their many challenging tasks be efficiently tackled.