Zur Morphologie,Histochemie, Tagesperiodik und Biologie der Operculardrüse bei Labriden und Scariden (Pisces)

A mucous gland is described, which is responsible for the production of the slime envelope in scarids and labrids. For this gland the name ‘opercular gland’ is suggested. The gland is developed, to a greater or lesser extent, in most of the genera examined. Morphological and histochemical studies indicate that the form of the gland is characteristic of the genus. Labrids and scarids can be divided, histochemically, into 3 groups: (1) opercular gland secretes only neutral MPS; (2) opercular gland secretes both neutral and weakly acidic MPS; (3) opercular gland secretes neutral MPS, weakly acidic and strongly acidic MPS (the strongly acidic MPS are probably sulphated). Species are found in all 3 groups with granular cells which secrete a tyrosine containing glycoprotein. The fish can be made to produce the mucous envelope by stimulation of the parasympathetic nervous system using pilocarpine. It is, therefore, assumed that the gland is controlled by the nervous system. Morphological studies of the gland show that the mucous is normally synthesised only in the evening, i.e. when it is needed; no storage takes place. Continuous light experiments have shown the gland to possess an endogenous rhythm of the same frequency as the fish's activity rhythm. Even those labrids which sleep under sand produce mucous. The average area of the longitudinal section of an opercular gland cell is more than 500 µ² in those species which produce a complete envelope, and usually somewhat less in the other species examined. The possible importance of the opercular gland in taxonomical and phylogenetical studies is discussed.     

Einfluß von Benetzungsspannung und lonen auf die Substratbesiedlung und das Einsetzen der Metamorphose bei Bryozoenlarven (Bowerbankia gracilis)

Settlement and metamorphosis in larvae of Bowerbankia gracilis depend on the wettability of the substratum. The wettability of a solid can be characterized by it's specific contact angle, . Larvae settle on solids with angles >17°, but not on surfaces with high wettability properties. In an attempt to explain this phenomenon, we consider the larvae as a second liquid and their attachment as a second wetting. In such case, water and larvae would compete in wetting the substratum. Adhesion can be accounted for by assuming the wetting tension of solid to water to be lower than that of the larval surface (|_solid/water| < |_solid/larvae|). Adhesion would thus be favoured energetically. The rate of settlement and that of metamorphosis are demonstrated as depending on the degree of contact angle, , in an all-or-none fashion. Settlement of larvae on high-wetting solids is prevented by high capillary pressure accruing at the point of contact. Metamorphosis is initiated by contractions occurring after adhesion. Application of CsCl or KCl induces such contractions and metamorphosis in free-swimming larvae. MgCl₂ prevents the onset of metamorphosis but not adhesion. Two mechanisms are considered as possibly accounting for induction of metamorphosis: (1) mechanical stimulation by shearing the cilia at the point of contact, and (2) a chemical stimulation of the cell membrane after application of K⁺ or Cs⁺.     

In situ beziehungen zwischen nahrungsangebot und aufgenommener Nahrung bei 5 Blennius-Arten (Pisces) des Mittelmeeres

Eight epiphytal samples were taken from the upper littoral at Banyuls-sur-Mer (French Mediterranean coast) and the fauna living on the thalli of algae or between bivalves was examined. Intestinal food contents of 67 specimens of 5 Blennius species (B. trigloides, B. canevae, B. sphinx, B. incognitus, and B. dalmatinus) occurring in the same biotope were also investigated. The epiphytal samples consisted of a rich supply of amphipods, bivalves, and algae. Amphipods are the preferred food of the Blennius species examined. These fishes also consume large amounts of copepods and algae, and small quantities of halacarids, bivalves, and ostracods. In addition to serving as a substrate for the main food-animals of the fishes, the algae themselves constitute an important food source. Presumably, for these reasons, the fishes remain close to the area inhabited by the algae on rocky substrates.     

Kenntnisdefizite bei Stoffeigenschaften und ihre Folgen

The data situation to chemical substances is unsatisfactory— in spite of in part considerable efforts in the last decades. One knows still very little on the subject of the dangerous characteristics of chemical substances. The consequences of this ignorance have primarily the employees to carry. They get sick due to a dealing with substances whose characteristics were not completely enlightened. But as well the enterprises have to suffer under it, after all, lose her experienced staff member and have to pay the costs about the Berufsgenossenschaften for these knowledge deficits. In the EU, the future European chemical policy is therefore discussed. The contribution explains the range of the sicknesses through dealing with substances with unknown characteristics.     

Dauerknospen (“Hibernacula”) bei den Bryozoa Ctenostomata in mesohalinen und vollmarinen Gewässern

Resting buds have been found in colonies of the ctenostomatous bryozoans Arachnidium cf. hippothooides, Valkeria uva, and Bowerbankia imbricata in mesohaline and marine waters. The development of zooids from the resting buds has been observed in different species. In each species examined, the colour of the resting buds is the same as that of eggs and embryos, probably because of similar reserves. The colour of the reserves may change with the food consumed. Resting bud formation is mainly induced by nutritional insufficiencies. The facts at hand suggest that salinity or temperature variations (within biologically adequate ranges) exert no direct influence on the formation of resting buds. Problems concerning food selection and immigration of bryozoans from the sea into the brackish-limic regions are brieffly discussed.     

Salzgehalt und Photosynthese bei marinen Pflanzen

Marine plants — phanerogams as well as algae — show a proportional decrease of photosynthetic rate, when the salinity is lowered by dilution with distilled water. Using natural water instead of distilled water, it is absolutely indispensable to take into consideration the carbon supply. Normally, the photosynthetic rate decreases in freshwater with low alcalinity, in comparison to marine water. On the other hand, using water with high contents of bicarbonates, assimilation rate is higher than in marine water. These results show that salinity may indirectly affect photosynthesis due to differences in carbon supply. The direct influence is caused by exosmosis in hypotonic media and is irreversible. — The author cannot but agree with the statement by Ogata and Matsui (1965): “It may generally be said that the changes in salinity, osmotic pressure, pH, and also carbon dioxide supply, particularly in natural sea-water, are rather inseparably associated.”     

Anreicherung,verteilung, umwandlung und ausscheidung von DDT-14C bei Solea solea (Pisces: Soleidae)

Common soles Solea solea (L.) are extremely suitable for studying the fate of pesticides in marine fish by means of laboratory experiments involving small-sized, accurately controlled, closed aquarium systems. In 5 different experiments, a total of 16 fishes of Age Group I were maintained in water of 10°C and 20‰ S continuously filtered through charcoal, and given oral doses of 0.85 μg DDT-¹⁴C up to 5 times/week. A total application of 1.7, 17 or 35 μg DDT-¹⁴C, corresponding to 3, 28, or 57 experimental days, resulted in 72, 60 or 43% DDT-¹⁴C accumulation. After feeding with 17 μg unlabelled DDT over a period of 4 weeks and final feeding with 1.7 μg ¹⁴C-labelled DDT for 2 days, S. solea displayed the same percentage (74%) of accumulated DDT-¹⁴C as after feeding with 1.7 μg DDT-¹⁴C without prior feeding. Therefore, the decreasing accumulation percentages with inereasing doses, i.e., with longer application periods, are due to elimination during the application period. During a period of 2 months in pesticide-free water, S. solea eliminated 62% of the DDT-¹⁴C which it had accumulated after feeding with 17 μg DDT-¹⁴C over a period of 4 weeks. The gastro-intestinal tract is assumed to be a major route of DDT elimination. Independent of dosage, there was a characteristic distribution pattern of accumulated DDT: brain, liver and gastro-intestinal tract ranked highest, while the concentration in skeletal muscle was lowest. Even during the elimination period the pattern appeared unchanged. DDE, DDD and a polar component occurred as metabolites, but in all organs more than 80% of the accumulated DDT remained unchanged. Percentages of metabolites were higher in liver and gastro-intestinal tract than in skeletal muscle. Prolonged exposure to DDT in the diet induced DDT transformation in the gastro-intestinal contents, most probably in the bacterial flora of the gut.     

Zur funktion,morphologie und histochemie der Schwanzdrüse bei Röhrenaalen (Pisces,Apodes, Heterocongridae)

A gland in the tip of the tail of the garden eel (Heterocongridae) is described. This gland produces a mixture of neutral and, to a lesser extent, acidic mucopolysaccharides. These slime substances appear to be used to glue the sand grains forming the tube walls in which the semi-sedentary eels live. The structure of the gland is described in relation to the normal mucous-containing goblet cells in the body epidermis of the garden eels. In the tail of young individuals, in two species, only goblet-like cells could be found. These differ in shape and histochemical reaction from the tail gland of the adult eels.     

Die stickstoffhaltigen stoffwechselendprodukte und ihre exkretion bei Paracentrotus lividus

The perivisceral fluid of Paracentrotus lividus (Lamarck) contains, as main end-products of the nitrogenous metabolism, ammonia, urea, creatine, creatinine and traces of uric acid. In the organs analysed, the distribution and abundance of ammonia and urea fluctuate considerably. the intestine was found to have the highest NH₄ ⁺?N and the lowest urea-N contents. The axial organ contained the highest amount of urea-N and the lowest quantity of NH₄ ⁺?N; the perivisceral fluid, including the coelomocytes, contained intermediate amounts. The special relations to hemal system and coelothel, the presence of excretory material, and the analogous conditions to other invertebrates, suggest that the coelomocytes and parts of the intestine and axial organ are excretophoric and able to synthesize urea. From the known distribution of ammonia and urea in echinoid species, it is concluded that the ability to synthesize urea must have developed and improved in efficiency during echinoid evolution. P. lividus is predominantly ureotelic. It excretes approximately 91% of the nitrogenous wastes released into the surrounding sea water as urea-N, and only 9% as ammonia-N. Ammonia, and most of the urea, are excreted via the body surface — probably through respiratory surfaces; however, one third of the urea is excreted through the intestine, since urea excretion decreases by this amount when the anus is sealed artificially.     

Verteilungskoeffizienten chlorierter Kohlenwasserstoffe zwischen Muskulatur und Leber bei Fischen

Measured partition coefficients (KL_M/L) related to lipid-concentrations between the muscle (C_ML) and liver (C_LL) tissue of two fish species (Abramis brama, Zoarces viviparus) exhibit nominal values of unity according the relationship KL_M/L=C_ML/C_LL=1 for persistent compounds such as highly chlorinated PCB and values above one for degradable compounds for example chlorinated cyclohexanes or DDT. The corresponding theory is presented. The relationship holds for samples for single fish as well as for pooled samples.     

Beziehungen zwischen Körperbau und Lebensweise bei Blenniidae (Pisces) aus dem Roten Meer. III. Morphologie des Auges

The morphology of the eyes of 3 salariin Blenniidae have been investigated and compared: Salarias fasciatus (inhabiting the sublittoral), Istiblennius edentulus (eulittoral), and Alticus kirkii (supralittoral). An effective protection against desiccation in A. kirkii is offered by the very thick cornea conjunctiva. Extension of the visual field in this species is achieved by protrusion of the eyes from the head, by recession of the dermal pigment, and by a relatively large lense which allows better perception of marginal rays. The retina of I. edentulus is adapted for amphibious vision by the existence of many prominent swellings and folds, and of a central depression into which the lens can be with-drawn. Thereby, the stronger rays of light retraction present on land are focussed on the swellings, since the retina of the depression is under-developed. The cornea conjunctiva and propria of A. kirkii are separated, and thereby constitute an additional eye chamber. Presumably this cavity possesses a lower refractive index than the cornea or water, and thereby enables sharp vision in air, since the light-concentrating effect of the curved cornea is thus diminished. Additionally, the shape of the cornea propria can be varied, since it is centrally connected with the lens; by this means the eye chamber can be extended, enabling displacement of the tocal point of the light rays to correspond with the momentary residence. The adaptations described here for I. edentulus and for A. kirkii have so far not been reported in other amphibious vertebrates.

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Hit Unterstützung der Deutschen Forschungsgemeinschaft     

Kombinierte Wirkung von UV-Strahlung und xenobiotika bei zweiSaccharomyces-Stämmen

The effects of eight chemicals on the inactivation rate of ultraviolet radiation on the colony building capabilities of two strains of Saccharomyces cervisae — a wild type strain and a mutant deficient in excision repair — were studied. The insecticide methoxychlor, the herbicide 2,4-dichlorophenoxyacetic acid, the fungicide pentachlorophenol and its metabolite tetrachlorohydroquinone, as well as the chemicals acrylonitrile and 2,3-dichloro-1-propene have no significant impact on the effects of UV radiation inSaccharomyces cerevisae. Depending on the concentration, trichloroethylene increases the sensitivity to UV radiation. The herbicide paraquat provides efficient protection against UV radiation at concentrations where a toxic effect cannot be observed even without UV. The results were rather similar for both strains.     

Beziehungen zwischen Körperbau und Lebensweise bei Blenniidae (Pisces) aus dem Roten Meer. I. Äußere morphologie

The external morphology of 5 species of salariin Blenniidae has been examined. Differences have been established between Salarias fasciatus living in the sublittoral, Antennablennius hypenetes, Istiblennius edentulus and I. flaviumbrinus inhabiting the eulittoral zone, and, especially, Alticus kirkii living on steep rocks of the supralittoral zone. The rays of the anal and (partly) pectoral fins terminate in little hooks; these are most pronounced in A. kirkii and least developed in S. jasciatus. The pelvic fins are short and broad in A. kirkii, but long and slender in the other 4 species. These structures make it possible to cling to uneven substrates. Fins are protected from rough rocks by a well developed cuticula; this is thickest in A. kirkii. Respiratory organs, adapted to function on land, have been discovered in the form of cutaneous blood vessels on the heads and the bodies of A. kirkii, and (less numerous and less developed) in I. edentulus and I. flaviumbrinus. Sensory organs have become specialized in A. kirkii; the eyes protude from the head, and the lateral line is reduced to a small relict. S. fasciatus and A. kirkii must be regarded as terminal representatives of a sequence of development which followed a trend toward the amphibian way of life.     

Betriebliche Umweltinformationssysteme (BUIS) Anforderungen und struktureller Aufbau

Appropriate organization structures, environmental controlling systems, and corporate environmental information systems (CEIS) are generally considered to be the essential instruments of a modern environmental management. Frequently, acceptance problems have been observed with respect to the installation of a CEIS due to the facts that there are no legal demands to implement such a system and, on the other hand, that theoretically based definitions of standards and structural principles of an CEIS are not yet available. As a consequence, different isolated solutions with rather low efficiency were hurriedly implemented by various companies. Regarding more precise request profiles for CEI systems, the present paper deals with the structural environment and the priority targets of an enterprise and with the organizational integration of environmental tasks. The operationalization into typical function fields yields tools to derive rough enterprise models, to analyze information streams and to select enviromentally relevant information as well as the routes which they tend to go. Based on these fundamental instruments, a CEIS architecture (structure and organization) can be developed whose realization is eventually supported by a ten-step plan. Existing EDP solutions are deliberately excluded in order to verify the general validity of the system architecture and to encourage creative potentials. The CEIS concept presented here, however, requires a transformation into operative practices, i.e. adjustment, completion, and combination of the elements concerning the detailed conditions of the enterprise under study.