bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Estimation of Phosphate and of Total Phosphorus in Sea Waters
Authors: Harvey H. W. 
Published: May 2009

A simple photoelectric meter is described which allows the molybdenum blue formed in sea water, due to the presence of phosphate, to be estimated within that due to ± 0·25 mg. phosphate-P per m.3.The effects of concentration of acid, molybdate, reductant, temperature and suspended particles on the rate of formation, fading and amount of molybdenum blue, formed in sea waters containing phosphate are detailed.Intramolecular changes taking place during storage of molybdate solutions, and while being mixed with acidified sea water, have been investigated.The hydrolysis of organic phosphorus compounds in acidified sea water at 140° C , and the prevention of arsenate formation, are described.Procedures, resulting from these investigations, for the estimation of phosphate, and of total phosphorus, are described.The growth of bacteria and the physical adsorption of organic phosphorus compounds in solution on the walls of glass vessels used for storage of sea water have been investigated, and a method of prevention evolved.
Structure, Tadpole and Bud Formation in the Ascidian Archidistoma
Authors: Berrill N. J. 
Published: May 2009

Archidistoma is a genus created for a species discovered and described briefly by Garstang in 1891 as A. aggregatum. It has been found at different times only in the Plymouth region, the original locality, attached to rock surfaces in a few feet of water. Recently, however, it has been found near Cape Hatteras on the eastern American coast (Van Name, 1945), suggesting either harbour to harbour transportation by ship bottom, or that its inconspicuous appearance has obscured a wide distribution.This form is of considerable interest as it represents a type less specialized in zooid structure, nature of tadpole, and method of budding than any merosomatous ascidian except the diazonids. Diazonids are oviparous and have the simpler development and tadpole associated with small eggs, although there is a more elaborate branchial sac correlated with the relatively large size of the mature zooid.ColonyThe colony consists of a brownish tough matrix forming a thin encrustation on stones and shells, with individual zooids (a few millimetres long), partly embedded in the test but for the most part extending freely in clumps usually of three or four. Sand grains and round particles adhere to or become buried within the test, making this form the most inconspicuous of ascidians.Structure of ZooidThe zooid is divisible into a thorax and a long slender abdomen (Fig. 1). There is no postabdomen, nor is there hypertrophy of the ventral test vessels, thereby segregating Archidistoma as a type from that of the synoicids (polyclinids) and the clavelinids respectively.
The Development, Morphology and Budding of the Ascidian Diazona
Authors: Berrill N. J. 
Published: May 2009

Diazona is represented in European waters only by Diazona violacea Savigny. It is a compound ascidian forming massive colonies of spectacular size and appearance. In many ways it is the most interesting of all ascidians, for in its adult structure it straddles two commonly accepted orders and in itself is a strong argument against such a division; it is the only oviparous and small egged compound ascidian, two features undoubtedly primitive; and its manner of budding is the simplest and probably is the basic type for the group as a whole. Only fragmentary descriptions of the morphology and reproduction exist, and a more or less complete account of the various stages of the life cycle may be of some value. The family Diazonidae includes, in addition to Diazona itself, the genera Tylobranchion of subantarctic regions, and Rhopalea of Mediterranean and northern waters. In its entirety Diazona appears to link with such divergent forms as Ciona on the one hand and Archidistoma on the other. The fact that Diazona is obtained by dredging in relatively swift offshore waters and lives poorly in an aquarium probably accounts for the existing unsatisfactory state of knowledge of most of its phases. Most of what is known concerns asexual reproduction; and attention has been given, at various times, primarily to the process of regeneration, rather than bud formation, for example by Della Valle (1884), Caullery (1914), Oka (1906) under the name Aphanobranchion, and by Salfi (1926).The material of the present account was collected at various times in the Plymouth area from the Mewstone and Eddystone grounds.
The Effect of Narcotics on the Endogenous Respiration and Succinate Oxidation in Oyster Muscle
Authors: Humphrey George Frederick 
Published: May 2009

The action of the following compounds on homogenates of the adductor muscles ofSaxostrea commercialiswas studied: urethane, phenyl urethane, chloral hydrate, salicylic acid, morphine, caffeine, barbitone, benzoic acid, salicylamide and benzamide.It was found that, except for 0·05 M urethane, the endogenous oxygen consumption was reduced by all these compounds when present in concentrations ranging from o·001 to 0·05M. The oxidation of succinic acid was partially inhibited by these substances.These findings are discussed in relation to similar studies on other tissues.
The sulpholipids of plants I. The distribution of sulpholipids and phospholipids among the major plant classes
Authors: Collier Rosemary , Kennedy G. Y. 
Published: May 2009

It is shown that sulpholipid is the predominant acetone-insoluble lipid of grass, sphagnum moss, Selaginella, and of some blue-green, green and brown algae.This sulpholipid is separable into three entities by paper chromatography.Phospholipid predominates over sulpholipid in red algae, fungi and the fluffy pericarp of the broad bean.The sulpholipid in these plant tissues gives a single spot on paper chromatogramA relationship between sulpholipids and photosynthesis is suggested.
A study of the diatoms of the Ouse Estuary, Sussex I. The movement of the mud-flat diatoms in response to some chemical and physical changes
Authors: Hopkins J. Trevor 
Published: May 2009

The analysis shows that the diatom community resides mainly in the top 2 mm of the mud and when in bright light the community moves less than 1 mm towards the surface of the estuarine mud, although the colour of the mud changes noticeably.The fine mud supports more diatoms than the coarse mud, and the community in fine mud is nearer to the mud surface, but this is probably caused by the more rapid extinction of light in fine mud than in the coarse mud, while also large spaces between the coarse mud particles may offer less protection from the effect of tidal scour than in fine mud, this giving contributory explanation for the less abundant community in coarse mud.
Light, temperature and the breeding of Balanus balanoides
Authors: Barnes H. 
Published: May 2009

Variations in the breeding habits of cirripedes are discussed.The effect of temperature and light during various stages of gonad development has been determined for B. balanoides.Constant illumination inhibits breeding, the inhibition relating to the later stages of gonad development.There is a critical temperature above which breeding will not take place, the level of which may possibly be raised by decreased periods of illumination. A period of 4–6 weeks at less than 12 h of light per day and below the critical temperature is required for maturation of the gametes. It is difficult to advance the date at which egg-masses are laid down by more than a few weeks.The results are discussed in relation to the animal's ecology. There is a very close adaptation to boreo-arctic conditions; the north-south gradient in the time at which the eggs are fertilized is related to the temperature gradient but the constancy from year to year of this date in any one locality under the same micro-environment cannot be explained on the basis of temperatures. Light periodicity is probably involved.
The iron content of sea water
Authors: Armstrong F. A. J. 
Published: May 2009

A method, suitable for routine use, of determining total iron in sea water is described. The water is acidified to about o·13N with hydrochloric acid and is heated for 5 h in an autoclave at 140°C. Iron is determined absorptiometrically with 1:1 phenanthroline after reduction with hydroxylamine hydrochloride.Tests of the method, collection and storage of samples and the variability of results are described.Iron contents of water samples from the English Channel and the Bay of Biscay are reported.
The responses ofScrobicularia plana(da Costa) to osmotic pressure changes
Authors: Freeman R. F. H. , Rigler F. H. 
Published: May 2009

The osmotic pressure of the blood ofScrobicularia planahas been measured when the animal is exposed to diluted sea water, and observations made on the behaviour of the animal when exposed to solutions of different osmotic pressure.The blood osmotic pressure shows no significant difference to that of the external medium except in very low salinities. The external medium with which an animal in its natural habitat comes into equilibrium is represented by the water above the mud rather than the water contained in the mud. Open animals equilibrate to 80% sea water in 4–5 h and to 60% sea water in 5–6 h. The osmotic pressure of the blood of animals that remain closed in dilute media is decreased by as little as 1·5% per hour.
Receptor elements in the coxal region of Decapoda Crustacea
Authors: Alexandrowicz J. S. , Whitear Mary 
Published: May 2009

In the 4th to 8th thoracic segments of decapod Crustacea, at the bases of the peraeopods, sensory organs of various kinds have been found. They have been observed in Homarus vulgaris, Astacus astacus, Palinurus vulgaris, Eupagurusbemhardus, Carcinus maenas, Maia squinadoand described in greater detail for Homarus, Carcinus and Maia.In all species examined there is in each peraeopod a proprioceptor consisting of a thin muscle with various nerve elements which extends from a point of the endophragmal skeleton situated near the ventral ganglia to the anteroventral part of the coxa. In the 4th to 7th thoracic segments of Homarus, in the 4th to 8th of Palinurus and Astacus, and in the 4th of the Brachyura, the receptor muscle is proximally attached to the tip of a chitinous projection of the endophragmal skeleton for which the term ‘receptor rod’ is proposed. In other instances it originates on the plate of the endosternite.The nerve components of this ‘muscular receptor’ are of two sorts: (1) motor nerves spreading their branches over the whole length of the muscle, and (2) processes of the sensory neurons distributing their ramifications on the connective tissue associated with the muscle at its proximal end. The arrangement of the sensory elements is different in various species, but they all exhibit one feature, unusual in invertebrates, viz. their cell-bodies are situated within the central nervous system and not outside it.
The photosensitive pigments in the retinae of deep-sea fish
Authors: Denton E. J. , Warren F. J. 
Published: May 2009

Measurements were made on the intact retinae dissected from freshly caught deep-sea fish. The unbleached retinae of such fish are not rose-pink like the retinae of most coastal fish or purple like the retinae of most freshwater fish, but are golden in colour.The golden colours are of photosensitive pigments which give retinal absorption curves similar in shape to frog's rhodopsin, but with maxima of absorption displaced on the average about 15 mμ. towards the blue end of the spectrum. The names ‘chrysopsins’ or visual golds are suggested for this group of pigments.The density of such photosensitive pigments is often very high. Retinal density changes on bleaching of more than 1.0 has been found for several deepsea fish. These probably correspond to absolute retinal densities of pigment of about 1.3, i.e. the absorption of 95% of blue-green light striking the retina.The conger and silver freshwater eels have retinae containing similar golden-coloured pigments. These eels begin their lives in the deep ocean and return there when mature to spawn.The significance of this type of photosensitive pigment in the vision of deep-sea fish is discussed, and an estimate is made of the depths at which deepsea fish will see daylight.
Breeding and marsupial development in laboratory-maintained Parathemisto gaudichaudi (Amphipoda)
Authors: Sheader Martin 
Published: May 2009

Parathemisto gaudichaudi (Guerin) (= P. gracilipes, Sheader & Evans, 1974) is a species of planktonic hyperiid amphipod which occurs in temperate and subpolar regions in both hemispheres (Dunbar, 1964; Kane, 1966; McHardy, 1970, Ph.D. thesis, Edinburgh University).Our previous studies have dealt with the taxonomy (Sheader & Evans, 1974), feeding and gut structure (Sheader & Evans, 1975), and morphological variation (Sheader, 1975) of P. gaudichaudi. These studies involved the routine maintenance of the species in laboratory conditions, allowing behavioural and developmental data to be gathered. The present paper deals with fertilization of the eggs and subsequent development up to the time of release from the marsupium. Animals were collected at a station 5 miles east of Blyth, Northumberland (55° 07′ N, 1° 22′ W). Laboratory culture is described in previous papers (Sheader & Evans, 1974, 1975).
Observations by scanning electron microscope (S.E.M.) on the oviducal gland sacs of Balanus balanoides at egg-laying
Authors: Walker G. 
Published: May 2009

Balanus balanoides (L.) is a cross-fertilizing hermaphrodite. The spermatozoa which are inseminated into the mantle cavity are initially inactive. Eggs are laid into the two elastic sacs of the oviducal glands (see Walley, 1965), which expand into the mantle cavity as more eggs are laid. The discharge of eggs into the elastic sacs also forces fluid out of the oviducal glands into the mantle cavity where the spermatozoa have been deposited. The fluid activates the inseminated spermatozoa (Walley, White & Brander, 1971; Walker, 1977).In order to effect fertilization of the eggs activated spermatozoa must pass across the oviducal gland sac wall. How the spermatozoa accomplish this is the subject of the present investigation.
Mixed algal feeding of Ostrea edulis larvae with Isochrysis galbana and Tetraselmis suecica
Authors: Helm M. M. 
Published: May 2009

Several authors have shown that by feeding bivalve larvae on a mixed algal diet growth is often better than when each of the constituent species of the diet was fed individually (Davis & Guillard, 1958; Walne & Spencer, 1968; Calabrese & Davis, 1970). The criterion upon which the value of the diets has been assessed has almost invariably been larval growth and rarely have the larvae been grown to metamorphosis.This paper reports the results of a series of trials with Ostrea edulis L. larvae which were fed with three diets. Two were single species diets of Isochrysis galbana Parke and Tetraselmis suecica (Kylin) Butch, while the third was a combination of these two species. Larvae were grown to metamorphosis on each of the diets and then for a further period with a common food to assess the value of the larval diet on the subsequent performance of the spat.
Energy metabolism of eggs during embryogenesis inBalanus balanoides
Authors: Lucas M. I. , Crisp† D. J. 
Published: May 2009

The partitioning and utilization of energy reserves during embryogenesis were followed in the cirripedeBalanus balanoidesand related to the described sequence of developmental stages. Egg volume and dry weights were measured. Between the recently fertilized egg and eggs containing well-developed embryos at the end of natural incubation there is a doubling of egg volume.The biochemical composition of the newly fertilized egg is dominated by TCA-insoluble protein (55 %). Neutral lipid accounts for 17 % of the dry weight, while phospholipid and polysaccharide contribute 3–5% and 5–7% respectively. About 36% of the TCA-insoluble protein is utilized duringin vivodevelopment, accounting for about three-quarters of the energy expenditure. During this time 40% of the carbohydrate and 20% of the neutral lipid reserves are also utilised. However, when starved adults retain their mature egg masses beyond the normal term, egg metabolism occurs largely at the expense of the remaining lipid reserves. These would be exhausted in a further 6–7 weeks and the embryos unable to survive. The ability of adults to postpone hatching may therefore have important implications for the energy reserves and viability of the newly hatched nauplii. Protein supplies most of the energy during embryogenesis, with neutral lipid assuming increased importance after development has been completed.Oxygen consumption of the egg masses measuredin vitrowas converted through aerobic oxycalorific equivalent into biochemical loss. This showed good agreement with direct measurement of summed energy losses of the biochemical components. It was apparent that oxygen uptake rate in the later stages was restricted by diffusion resistance due to egg packing, since eggs freed from the egg mass matrix showed a 30% increase in oxygen uptake and a reduction in development time.
Studies on the haemoglobins of the small Pogonophora
Authors: Terwilliger R. C. , Terwilliger N. B. , Hughes† G. M. , Southward† A. J. , Southward† E. C. 
Published: May 2009

Haemoglobin is present, often at high concentration, dissolved in the blood of all small Pogonophora so far examined.The haemoblobin ofSiboglinum fiordicumresembles annelid and vestimentiferan haemoglobins in having subunits with molecular weights of 15000–16700 plus traces of 35000–40000 MW material. 5.fiordicumhaemoglobin has 1 mol haem per 21500 g protein, and a similar lack of correspondence between subunits and mols of haem is shown by annelid and vestimentiferan haemoglobins. However,S. fiordicumhaemoglobin differs considerably from annelid and vestimentiferan haemoglobins in other respects, even though the three groups are closely linked taxonomically. The haemoglobin ofS. fiordicumhas a lower apparent molecular weight (Mr= 3.5–4.0 x 105) than that of annelid haemoglobins (Mr= 3–4 x 108) when measured under the same conditions. Pogonophore blood examined with the electron microscope does not show the two-tiered hexagonal structure found in annelid and vestimentiferan haemoglobins.S. fiordicumhaemoglobin also differs from annelid and vestimentiferan haemoglobins in amino acid composition.The haemoglobins of the small pogonophores examined have a very high affinity for oxygen. The P50ranges from 0.36 Torr in diluted blood ofS. fiordicum(15 °C) to 0.5–1.0 Torr in undiluted blood ofS. atlanticum(10 °C) ands. fiordicum(15 °C). Only a slight Bohr effect was found. The high oxygen affinity can be related to the wide range of Po2values experienced in the habitat and the need to transport oxygen to the deeply buried posterior end of the body that contains autotrophic endosymbiotic bacteria.
Vitamin A and carotenoids in certain invertebrates: II. Studies of seasonal variations in some marine crustacea
Authors: Fisher L. R. , Kon S. K. , Thompson S. Y. 
Published: May 2009

SummaryResults are given for measurements of fat, vitamin A and carotenoids in groups ofMeganyctiphanes norvegica, Thysanoessa raschii, Crangon allmani, C. vulgaris, Nephrops norvegicusand eyes ofHomarus vulgaris, collected at regular intervals for a year or longer.In both species of euphausiids vitamin A was consistently present mainly in the ester form and concentrated chiefly in the eyes. More than half the total astaxanthin was in the eyes. No other carotenoids were detected.Astaxanthin and vitamin A were accumulated by the euphausiids more rapidly during the spring and autumn-feeding periods associated with diatom outbursts than at other seasons. There was a delay inThysanoessa raschii, but not inMeganyctiphanes norvegica, between resumption of more rapid growth during spring and autumn and increase in concentration of vitamin A and astaxanthin. The difference was possibly due to differences in diet of the two species in relation to the seasonal biological composition of the plankton.In the euphausiids, concentrations of vitamin A and astaxanthin were much higher in larvae and in adults over 30 mm long ofM. norvegica, and in larvae and adults over 15 mm ofThysanoessa raschii, than in mature adults ofMeganyctiphanes norvegicaof 20–30 mm andThysanoessa raschiiof 13–15 mm, respectively. An inverse relationship between fat and vitamin A concentration was noted in both species throughout the year.InCrangonspp. andNephrops norvegicusthere was no evidence of any seasonal variation of either vitamin A or carotenoids. Differences in the carotenoid metabolism of the two species ofCrangonare discussed.
Leg disposition in the brachyuran megalopa when swimming
Authors: Atkins D. 
Published: May 2009

SummaryMany brachyuran megalopae swim with the legs disposed in a curious manner. The chelipeds and first two pairs of walking legs are folded tightly beneath the body, while the two posterior pairs are wrapped over the dorsum, the third pair being stretched out anteriorly, the dactylus, according to its length, touching or being looped round the eye-stalk. It is suggested that this posture gives stream-lining to the megalopa and improves its swimming. The described arrangement has been observed in all but three of some twenty-five species occurring at Plymouth.In the three exceptions, Corystes cassivelaunus, Thia polita and Pinnotheres pinnotheres (= veterum), all legs are carried folded beneath the body.Reference is made to previous descriptions of the folding of the legs in the brachyuran megalopa.
A penetrometer for use on water-covered beaches
Authors: Carruthers J. N. 
Published: May 2009

SummaryComments on the uses of penetrometers in general are followed by remarks upon an earlier one for use on dry beaches. Some discussion is given of the behaviour of beds of sand disturbed by shocks and converted thereby into a state of quasi-liquefaction. Finally, a description is given of a tall pull-down penetrometer which can be used on beaches covered by modest depths of water.
The occurrence of porphyrins in certain marine invertebrates
Authors: Kennedy G. Y. , Vevers H. G. 
Published: May 2009

SummaryA survey of forty-eight species of British marine invertebrates has shown that porphyrins which have not previously been described in these animals are present in three representatives of the Annelida, two of the Mollusca and two of the Echinodermata. The occurrence of protoporphyrin inAsterias rubenswas confirmed in a previous paper (Kennedy & Vevers, 1953b). A redfluorescent extract was obtained from the spongeTethya aurantium, but it contained too little material for further investigation. No trace of a porphyrin was found in the coelenterates, crustaceans and tunicates examined, although Moseley found ‘polyperythrin’ (which MacMunn later identified with the ‘haematoporphyrin’ ofAsteriasandArion) inFlabellumandFungia.Chlorocruoroporphyrin was found free in the starfishesLuidiaandAstropecten. Uroporphyrin was extracted from the soft dorsal integument ofDuvaucelia (= Tritonia) plebeia, and from the integument ofAplysia punctata, observations of interest in view of the widespread occurrence of uroporphyrin in mollusc shells.Coproporphyrin III was characterized from extracts of the viscera ofMyxicola infundibulum, Nereis diversicolorandChaetopterus variopedatus. Evidence of the occurrence of a penta-carboxylic porphyrin was obtained from paper chromatography of the extract from the gut ofChaetopterus.These findings are discussed in comparison with the distribution of porphyrins in birds and mammals.