More effective induction of spawning with long-acting GnRH agonist in the shi drum, Umbrina cirrosa L. (Sciaenidae, Teleostei), a valuable candidate for Mediterranean mariculture

Three experiments of spawning induction in shi drum, Umbrina cirrosa L., were performed in six different commercial Italian hatcheries from May to August (water temperatures: 19–29 °C; salinity: 21–37 p.p.t.). In the first experiment, 119 females (1–4.7 kg), subdivided into 29 lots, were injected with a single dose (2, 5, 8, 10, 15 and 20  μ g kg⁻¹ body weight) of short-acting gonadotropin- releasing hormone agonist (GnRHa-S), des-Gly10,[D-Ala6]-LH-RH ethylamide. In the other two experiments, 85 females (0.7–5.8 kg), subdivided into 22 and four lots, were treated with one (40 or 80  μ g kg⁻¹) or three doses (40  μ g kg⁻¹) of long-acting GnRHa (GnRHa-L), respectively. GnRHa-S stimulated spawning in 69% of the 29 treated lots; the number of eggs laid reached a maximum of 130 000 and a weighted mean of 29 200 total eggs kg⁻¹. GnRHa-L elicited a spawning response in 95% of the 22 one-dose treated lots; the number of laid eggs was higher than with GnRHa-S, reaching a maximum of 213 100 and a weighted mean of 59 400 total eggs kg⁻¹. The yield of developing embryos in 67% of the single GnRHa-L treatments was higher (sometimes up to three times) than with GnRHa-S. Triple treatments of the four lots of females with GnRHa-L always resulted in spawning responses; the best result corresponded to a number of total laid eggs of 358 900 eggs kg⁻¹ with a yield of 177 300 developing embryos.     

Seasonal changes in some blood chemistry parameters and in relative liver and gonad weights of pike (Esox lucius L.) from the River Danube

Samples from a natural population of pike (Esox lucius L.) from the River Danube were used in a 12-month study to determine seasonal variations in biochemical parameters of pike blood sera, hepatosomatic index (HSI) and gonadosomatic index (GSI). The ranges of enzyme activities for sample means were: aspartate aminotransferase (ASAT) 252.0–583.8 U 1⁻¹, alanine aminotransferase (ALAT) 4.9–11 -2 U1 and alkaline phosphatase (AP) 39.5–91.8 U1⁻¹. The ranges of other parameters analysed in serum were total protein 27.7–40.1 g 1 ¹, urea 0.57–l.52 mmol 1 ¹ and creatinine 21.2–118.6 μmol 1 ¹. The range of sample means for HSI and GSI were 1.28–4.16 and 0.07–20.2 respectively. Temperature ranged from 4.5 to 23.5°C. The activity of serum AP was positively correlated to water temperature in males only, while urea and creatinine showed a positive correlation to water temperature in individuals of both sexes. GSI was correlated significantly with HSI in females. Total protein reached the lowest values during the spawning period, while creatinine levels depended on both the sex and season.     

Pathways controlling the superoxide response during phagocyte differentiation: involvement of arachidonic acid and Ca2+ in the response to bacterial endotoxin

Abstract In contrast to the phorbol ester oxidative response, which only develops during dimethyl-sulphoxide (DMSO)-induced differentiation of the human leukemic myeloblast HL-60 cell-line, the endotoxin response was observed in undifferentiated and differentiated cells. The Ca²⁺ response to endotoxin, detected in both differentiated and undifferentiated HL-60 cells, consisted of a transient 10–50 nM increase in intracellular Ca²⁺. A very slow, irreversible increase in intracellular Ca²⁺ was detected at high 1–100 μg/ml endotoxin concentrations, and this effect, and the inositol phosphate response, correlated with the surfactant activities of various endotoxins and Lipid A. Arachidonic acid and sodium arachidonate 1–50 μM stimulated a large 200–500 nM and transient Ca²⁺ response in undifferentiated HL-60 cells, which was significantly greater than that elicited by 1–50 μM eicosapentaenoic acid, and was not observed at similar concentrations of arachidonic acid methyl ester or myristic acid. These concentrations (1–50 μM) of arachidonic acid were observed to have surfactant activities on the plasma membrane. At lower arachidonic acid concentrations a marked potentiation of both Ca²⁺ and oxidative responses to the chemotactic peptide fMet-Leu-Phe was detected. It is possible that the arachidonic acid released during phospholipase A₂ activation of neutrophils may be involved in cellular cross-talk and, at higher concentrations, in directly activating Ca²⁺ and superoxide production. It is also possible that previously reported effects of endotoxin at high concentrations are an vitro artefact of surfactant properties of endotoxin.     

Species of Anguilla as indicators of mercury in the coastal rivers and lakes of Victoria, Australia

Mercury concentrations in the axial muscle tissue of most (243) of the 254 Anguilla australis and most (20) of the 27 A. reinhardtii collected from 30 sites in coastal rivers and lakes in Victoria, Australia, during 1975–78 were well below the Australian statutory health limit (0.5 μg g⁻¹ wet weight). For A. australis the mean mercury concentration was 0.17 μg g⁻¹ (±0.16 s.d. , range 0.01–1.60 μg g⁻¹); for A. reinhardtii the values were 0.37 ± 0.23 μg g⁻¹ (range 0.12–1.10 μg g⁻¹). Statistical analyses showed that variation in mercury concentration due to total length accounted for only 13% of the total variation in A. australis and 2% in A. reinhardtii whereas locality accounted for 54 and 68%, respectively. Both species are thus considered suitable as indicators of mercury pollution.     

Normal ranges of some blood chemistry parameters in adult farmed Atlantic salmon, Salmo salar

Blood samples from healthy adult Atlantic salmon fed an optimal diet in net sea pens were collected at intervals from October to May. Haematological determinations and biochemical serum analyses were carried out on 20 fish in each of seven samples. The ranges of haemato-logical values for sample means were: haematocrit 44–49%, haemoglobin 8.9–10.4 g 100ml⁻¹, red blood cell count 0.85–1.10 × 10¹² l⁻¹, MCV 441–553 × 10⁻¹⁵ 1, MCH 94–106 × 10⁻⁶ g, MCHC 19.4–21.7 g 100ml⁻¹ and leucocrit 0.43–0.96%. The ranges of enzyme activities in serum, for sample means, were: alkaline phosphatase 647–988Ul⁻¹, aspartate aminotrans-ferase 202–351 Ul⁻¹ and alanine aminotransferase 4–8 Ul⁻¹. The ranges of the other parameters analyzed in serum were: total protein 41.6–56.6 gl⁻¹, albumin 18.3–24.3 gl⁻¹, albumin/total protein ratio 39.3–44.0%, creatinine 26–46 μmol, triglycerides 2.53–4.98 μmol and cholesterol 9.3–12.8 μmol. These values are considered to be the normal ranges in healthy fish. Variations due to seasonal changes, and the clinical significance of the selected parameters, are discussed. Data showing the reproducibility of the biochemical analyses in serum are presented.     

Some effects of low pH and calcium on the growth and tissue mineral content of yearling brown trout, Salmo trutta

Yearling brown trout, Salmo trutta , were exposed to low mineral content water (nominal concentrations of 20μmol 1⁻¹ magnesium, 7.7 μmol 1⁻¹ potassium, 44 μmol 1⁻¹ sodium) over a pH range of 4.0–5.2 with ambient calcium concentrations of 2.5–60 μmol 1⁻¹. All fish died at pH 4.0 and 4.2 irrespective of ambient calcium concentration and also at pH 4.4 with only 2–3 μmol 1 ⁻¹ calcium (that is calcium-free water except for that leached from the diet or excreted by the fish). Good growth rates were obtained over the remaining treatments which extended down to pH 4.4 with as little as 7 μmol 1⁻¹ calcium. When starved, weight loss was inversely correlated with pH. Effects on plasma chloride, percentage dry weight and calcium, potassium sodium, and phosphorus contents of skin, muscle and bone tissue were also investigated. These demonstrated pH effects on mineral metabolism in starved fish, but no effects were detected in fed fish.     

Plasma steroid concentrations in relation to the reproductive cycle of cultured male Rhamdia quelen

Seepage water through a lake bottom and the layering of tight and high-permeable layers in the aquifer produce groundwater under greater pressure than the water column of the lake. This results in under-water springs and seepages. When spawning substrata were available, there was a spatial correlation between the degree of groundwater influx and the redd density of brown trout Salmo trutta . In high density spawning areas with > 100 observed redds ha⁻¹, the mean seepage water influx during spring was c . 1200 ml m⁻² min⁻¹ compared to a mean flux of 113 ml m⁻² min⁻¹ in low density spawning areas with 5–10 redds ha⁻¹.     

Planktic cyanophytes and their ecology in the shallow Lake Mikri Prespa, Greece

Cyanophytes dominated the phytoplankton of shallow Lake Mikri Prespa during the period May 1990 to September 1992 (76.5 and 52.0% of the total phytoplankton biomass in 1990–1991 and 1991–1992, respectively). Biomass peaks were observed in autumn (from 5.2 to 34.5 g m^-3) when low dissolved inorganic nitrogen, high phosphate phosphorus and low Z_cu to Z_mix ratio prevailed. The dominant species were Microcystis aeruginosa and M. wesenbergii. These represented 64 and 86% of the cyanophyte biomass in 1990–1991 and 1991–1992, respectively and revealed similar patterns of seasonality forming biomass peaks in late summer - autumn. Small chroococcalean cyanophytes (< 2 μm) showed also similar temporal distributions. Of the filamentous cyanophytes, the most important species was Anabaena lemmermannii var. minor which formed peaks in late summer and autumn (2.6 and 1.1 g m^-3 in 1990 and 1992, respectively). Rainfall and the N:P ratio were probably the main factors influencing the seasonality of all of the filamentous cyanophytes in the lake. Cyanophytes, tended to increase at temperatures higher than 16 °C and at inorganic nitrogen concentrations lower than 100 μg 1^--¹. The frequent mixing of the water column did not seem to prohibit the substantial increase of the group.     

Seasonal changes in reproductive function of the rainbow trout (Salmo gairdneri)

The sequential changes in serum oestradiol 17β (measured by specific radioimmunoassay), vitellogenin (measured by phosphoprotein phosphorus content) and total calcium (measured by fluorimetry) in male and female rainbow trout under a simulated natural photoperiod cycle were investigated. Resting levels of 130 pg/ml serum oestradiol in both male and female fish were found in April and May. In the female, levels reached a peak of 4800 pg/ml in October, and almost returned to resting levels just prior to spawning in mid-January. No significant change from resting levels was seen in the male fish.
In both male and female fish levels of 25 μg/ml serum phosphoprotein phosphorus and 10–14 mg % total serum calcium were found from April to July. Coincident with the rise in oestradiol 17β, in the females serum levels of phospho-protein phosphorus and total calcium increased to 400 uβg/ml and 58 mg% respectively just prior to spawning. In the males no significant change in either of these values was observed throughout the cycle. These results strongly support the hypothesis that photoperiod is the major factor in the environmental control of reproductive activity in the rainbow trout.     

Comparison of epilithic and epixylic biofilm development in a boreal river

SUMMARY. 1. We assessed substratum effects on lotic biofilm development by placing glass and white pine sampling units in a fourth-order boreal river, and analysing, at 6-week intervals, upper-surface biofilms for ATP, chlorophyll, ergosterol, and the activities of nine exoenzymes.
2. All parameters, except chlorophyll standing stock (range 80–320 μg dm⁻²) and β-xylosidase activity (range 0.4–4.8 μmol h⁻¹ dm⁻²), were significantly greater for epixylic biofilms than for epilithic ones, but the magnitude of the increases varied from 2 to 5 fold, showing that, even under similar hydrodynamic conditions, epilithic and epixylic biofilms are structurally and functionally distinct. For example, ergosterol concentrations ranged from undetectable to 0.93 μg dm⁻² for epilithon and from 11–49 μg dm⁻² for epixylon; corresponding ranges for ATP were 1.6–3.7 (epilithon) and 4.2–7.7 μg dm⁻² (epixylon), for acid phosphatase activity: 2.3–4.9 and 20–41 μmolh⁻¹dm⁻², and for alkaline phosphatase activity: 1.9–8.1 and 29–150 μmol h⁻¹dm⁻², respectively.
3. The more extensive epixylic development was attributed to utilization of the wood substratum as a supplemental carbon source and to a higher density of microbial attachment sites.     

Evaluation of biochemical methods for the non‐destructive identification of sex in upstream migrating salmon and sea trout

Female‐specific markers of reproductive activity [plasma 17β‐oestradiol (E2), vitellogenin (VTG) and alkali‐labile phosphoprotein phosphorous (ALP)] were measured over 12 months in a captive population of brown trout Salmo trutta . During the early months of the reproductive season (February to May) and using the concentration of plasma E2 or plasma ALP as a marker for females the proportion of fish in which sex was misidentified was high (15–50%). The misidentification rate was considerably lower (1–8%) using plasma VTG. Preliminary evaluation of a commercial immunochromatographic VTG test system as a screen for the presence or absence of VTG in plasma from brown trout provided results that were consistent with those obtained from direct measurement of plasma VTG levels by enzyme‐linked immunosorbent assay (ELISA). These preliminary conclusions were verified by sampling upstream‐migrating anadromous brown trout, sea trout, and Atlantic salmon Salmo salar trapped over a 6 month period. Plasma E2 levels did not satisfactorily discriminate between male and female sea trout and Atlantic salmon. Plasma VTG levels in both species, however, were bimodally distributed and it was assumed that this divergence corresponded to male (plasma VTG levels <10 μg ml⁻¹) and female (plasma VTG levels >800 μg ml⁻¹) fishes. Plasma ALP provided a more accurate indication of sex in the wild Atlantic salmon and sea trout than was suggested by the pilot study on captive brown trout. The commercial immunochromatographic VTG test system provided results that were wholly consistent with the data obtained from the trapped fishes by direct measurement of plasma VTG.     

Plasma insulin levels during the spawning migration of the pink salmon, Oncorhynchus gorbuscha

Plasma insulin concentration was measured by homologous radioimmunoassay in male and female pink salmon. Oncorhynchus gorbuscha , during spawning migration in the Fraser and Thompson Rivers, British Columbia. Although the fish ceased feeding prior to entering fresh water, plasma levels of insulin remained stable (males) or even elevated (females) during the final stages of oogenesis and spermatogenesis, decreasing thereafter. Mean concentrations ranged from 0–69 to 1.24 ng ml⁻¹ in males and from 0.33 to 0.88 ng ml⁻¹ in females. At all stages in the anadromous migration where a significant difference in plasma insulin levels between the sexes was observed, males had higher concentrations than females.     

Biology of the acid-tolerant fish species Umbra pygmaea (De Kay, 1842)

In The Netherlands, the mudminnow Umbra pygmaea mainly occurs in water bodies with a pH ranging from 3–5 to 4–0, an alkalinity less than 0.1 meq 1⁻¹ and a calcium content below 100 μmol 1⁻¹. The abundance of mudminnows is inversely related to the pH and the presence of predatory fish species. Experimental studies show that If. pygmaea is extremely acid-tolerant. Exposure to media with pH values ranging from 4.0 to 7.0 did not cause mortality or significant changes in blood plasma osmolarity and haematocrit. At pH 3.0 no mortality was recorded although a strong decrease in the plasma osmolarity was observed. Exposure to pH 2.8 and calcium concentrations of 100 or 500 μ mol 1⁻¹ for 10 days caused 70% and 40% mortality respectively. The growth, reproduction and feeding of mudminnows are described. Age-growth and length-age relationships were calculated. Gonadal development started between September and January. The highest Gonado Somatic Index was recorded in spring. Spawning occurred from April to May. Fecundity of a sample of females was assessed. Nematocera provided the main item of diet of U. pygmaea; the microfauna ingested was dominated by Cladocera. The adaptations of mudminnows to acid environments are discussed.     

Effects of cadmium chloride on the development of rainbow trout Oncorhynchus mykiss early life stages

The sub-chronic (28–56 days) effects of exposure to low concentrations of cadmium (Cd; 0·05, 0·25, 0·50 and 2·50 μg l⁻¹) shortly following fertilization on embryos, larvae and juvenile rainbow trout Oncorhynchus mykiss were examined. Premature hatching occurred at lower concentrations (0·05 and 0·25 μg l⁻¹ Cd), however, delayed hatching was seen in the 2·50 μg l⁻¹ Cd group, with >90% of hatching occurring on the last day of the hatching period. Larval growth was negatively affected by Cd exposure in a concentration-dependent manner. Larvae exposed to 2·50 μg l⁻¹ Cd were 13·9 ± 0·8% shorter in total length ( L _T) and weighed 22·4 ± 3·5% (mean ± s . e .) less than controls at the end of the exposure period. Plasma sex steroid concentrations (oestradiol in juvenile females and 11-ketotestosterone in juvenile males) were elevated (four- to 10-fold over controls) in exposed fish in both males and females, following 28 days of exposure to 0·05, 0·25 and 0·50 μg l⁻¹ Cd, respectively. These results suggest that environmentally realistic concentrations (in the μg l⁻¹ range) of Cd can affect the development of O. mykiss impacting embryos, larvae and juvenile fish.     

Lichen recolonization in London under conditions of rapidly falling sulphur dioxide levels, and the concept of zone skipping

HAWKSWORTH, D. L. & McMANUS, P. M., 1989. Lichen recolonization in London under conditions of rapidly falling sulphur dioxide levels, and the concept of zone skipping. The lichen flora on trees and wood at 50 sites in north-west London was examined in 1988 to determine what changes had taken place since 1980, a period when mean winter SO₂ levels had fallen from around 130 μg m^-3 to within the range 29–55 μg m^-3 in the study area. Forty-nine species were found. The fruticose lichens Evernia prunaslri and Ramalina farinacea now occur in many central London parks, and the yellow green foliose Parmelia caperata was discovered at 12 sites (previously only at one, Ruislip, in 1980). Comparable numbers and growth forms of species occurred throughout the area. An assemblage of zone 4–5 species (Hawksworth & Rose, 1970 Nature, 227: 145–148) tolerant of mean winter SO₂ levels of 60–70 μg m^-3 failed to penetrate central London, although more sensitive species of zones 6 and 7 had; this phenomenon, which has not previously been reported, is referred to as 'zone skipping' and is attributed to the speed at which mean sulphur dioxide levels in London have fallen. Species returning are those to be expected on the basis of previously-published field correlations with mean winter SO₂ levels. Twenty-five species not seen within 16 km of the centre of London on trees or wood during this century were found; of these, eight had not been seen during the last 200 years.     

Bioactivity of stored luteinizing hormone-releasing hormone analogue (LHRHa) in sea bass, Lates calcarifer Bloch

The spawning induction activity of dissolved and pelleted (D-Ala⁶, Pro⁹ N ethylamide) luteinizing hormone-releasing hormone analogue (LHRHa) stored for various periods was assessed in mature female sea bass. The spawning response of mature fish was reduced significantly after injection of dissolved LHRHa (20 μg kg⁻¹) stored for more than 90 days in a refrigerator (4–10°C) or for more than 30 days at room temperature (28–30°C). Similar to fish administered fresh preparations of LHRHa, fish spawned successfully after injection of a solution of LHRHa previously frozen, subjected to alternate freezing and thawing, exposed to sunlight or implanted pelleted LHRHa (50 ng kg⁻¹) stored at room temperature for 30–120 days. Loss of hormone bioactivity after prolonged storage may have been due to bacterial growth in solubilized preparations. Injection or implantation of stored LHRHa did not influence egg production among treated sea bass. These results demonstrated the relatively prolonged shelf life of stored LHRHa.     

The effect of cryptolepine on the morphology and survival of Escherichia coli, Candida albicans and Saccharomyces cerevisiae

The antimicrobial activity of the indoloquinoline alkaloid, cryptolepine, isolated from Cryptolepis sanguinolenta (Fam. Periplocaceae) was determined against selected micro-organisms. The minimum inhibitory concentration (MIC) ranges obtained, expressed as μg ml⁻¹, were: 5–10 for Saccharomyces cerevisiae NCPF 3139; 10–20 for S. cerevisiae NCPF 3178; 20–40 for Escherichia coli NCTC 10418; 40–80 for E. coli NCTC 11560, Candida albicans ATCC 10231 and C. tropicalis NCPF; and 80–160 for C. albicans NCPF 3242 and NCPF 3262.
Biocidal effects were noted at concentrations 2–4 times those of the MIC of the alkaloid following challenge with 10⁶ cfu ml⁻¹ of micro-organisms. Time-kill studies showed a reduction in viable count from 10⁶ to < 10 cfu ml⁻¹ in 4 h in C. albicans ATCC 10231 exposed to 320 μg ml⁻¹ of the agent; 3 log cycle reductions were recorded for the 6 h counts of E. coli NCTC 10418 and S. cerevisiae NCPF 3139 exposed to 40μg ml⁻¹ and 160 μg ml⁻¹ of the alkaloid respectively.
These results were consistent with findings using scanning electron microscopy. Exposure of cells to biocidal concentrations of cryptolepine produced filamentation prior to lysis in E. coli NCTC 10418 and extreme disturbance of surface structure, including partial and total collapse, followed by lysis in C. albicans ATCC 10231 and S. cerevisiae NCPF 3139.     

The effect of humic substances on the toxicity of aluminium to adult rainbow trout, Oncorhynchus mykiss (Walbaum)

Some physiological parameters were measured in adult rainbow trout during a 10-day exposure to 180 μg Al_total l⁻¹ in acid water (pH 4.7) with or without humic substances (10 mg l⁻). The fish were acclimatized to pH 5.0 for 7 days prior to the experimental treatments.
Chemical analyses revealed that, in the presence of human substances, 74–80% of the A1 was organic bound, while in the absence of humic substances most of the Al(987percnt;) occurred in the inorganic form.
Al bound to humic substances (13–150 μg l⁻¹) did not alter the plasma NaCl-concentration, nor the haematocrit value, of rainbow trout during an exposure period of 10 days. This contrasts with the high death rate obtained within 2–3 days when most of the A1 (175 μg l⁻¹) was in the inorganic form. The lethality was accompanied by a 25% decrease in the plasmaconcentration of NaCl and a doubling of the haematocrit value. Bulk analysis revealed that when the metal was present in inorganic forms the total Al content of the gills (75 μg A1 g⁻¹ wet weight) was 15 times higher than when it was present as bound to the humic substances. These experiments showed that the accumulation of A1 at the gills was accompanied by physiological disturbances, both being a function of the chemical speciation of Al.     

Anti-bacterial activity of synthetic N-heterocyclic oxidizing compounds

Synthetic chlorochromate derivatives of pyridine and quinoline were active in vitro against type cultures of Escherichia coli (ATCC 128), Staphylococcus aureus (ATCC 14775), Pseudomonas aeruginosa (ATCC 10145) and Bacillus subtilis (NCTC 8236). The minimum inhibitory concentrations (MIC) were 125–250 μg ml⁻¹ and 250–500 μg ml⁻¹ for pyridinium chlorochromate and quinolinium chlorochromate, respectively. An established derivative of quinoline (Perfloxacin) had an MIC of 125–250 μg ml⁻¹. The extinction time for 10⁵ cfu in broth was 90 min for pyridinium chlorochromate and 120 min for quinolinium chlorochromate, except for B. subtilis which survived up to about 180 min and 360 min. A combination of the two compounds produced an antagonistic effect. The 50% lethal dose (LD₅₀ toxicity) in mice was estimated at 76 μg g⁻¹ and 33 μg g⁻¹ body weight for the quinolinium and pyridinium chlorochromates. The compounds also exhibited some potential for suppressing a simulated staphylococcal infection in mice at the dosage levels of ca 22 μg g⁻¹ for pyridinium chlorochromate and 45 μg g⁻¹ for quinolinium chlorochromate.     

The weight-volume relationship of the test of Alveolinella quoyi: Implications for the taphonomy of large fusiform foraminifera

Severin, Kenneth P. & Lipps, Jere H. 1989 01 15: The weight-volume relationship of the test of Alveolinella quoyi: Implications for the taphonomy of large fusiform foraminifera. Lethaia , Vol. 22, pp. 1–12. Oslo. ISSN 0024–1164.
Alveolinella quoyi , the largest living fusiform foraminifer, can be used to infer the paleobiology of extinct fusulinids and alveolinids. We measured test plus organic material weight, test weight, and test volume for A. quoyi , allowing the calculation of test density under various conditions. Tests have an average of 43% chamber space, and an average density of 1.5 gcm^-3. Living individuals can only fill an average of 39% of their chamber space with protoplasm. If they fill the remaining space with sea water, average effective test density is 0.953 gcm^-3, if the space is filled with a gas the density is 0.671 gcm^-3. Living individuals can withstand current velocities of 3–4 m sec^-1, velocities greater than commonly occur in A. quoyi's habitat. Dead tests have lower effective densities than many carbonate sedimentary particles (0.508 g cm^-3 if the chamber space is gas filled, 0.953 g cm^-3 if it is sea water filled), making their settling velocities slow relative to similarly shaped and sized particles. Their large size and high traction velocities (>0.2m sec^-1) makes them unaffected by gentle currents which can remove 100–200 μ sized particles from the sediment. Their low settling velocity will tend to concentrate A. quoyi tests during subsequent resuspension, creating a layer of tests near the sediment-water interface. Concentrations of extinct fusiform foraminifera may have formed in a similar manner. □ Lorger foraminifera, test weight, test volume, test density, taphonomy .