Extracellular amylase(s) production by fungi Botryodiplodia theobromae and Rhizopus oryzae grown on cassava starch residue

The fungi Botryodiplodia theobromae and Rhizopus oryzae produce extracellular amylase when grown on a liquid medium containing 2% (WN) soluble starch or cassava starch residue(CSR) (as starch equivalent), a waste generated after extraction of starch from cassava, as the sole carbon source. Using CSR as the sole carbon source, the highest amylase activity of 3.25 and 3.8 units (mg, glucose released x ml(-1) x h(-1)) were obtained in shake flask cultures during the late stationary phase of growth of B. theobromae and R. oryzae, respectively. These values were slightly lower than the values obtained using soluble starch as the carbon source. Maximum enzyme synthesis in CSR incorporated medium occurred at the growth temperature of 30 degrees C and pH 6.0. Presence of inorganic NH4+ salts like ammonium acetate and ammonium nitrate in culture medium yielded more amylase than the other nitrogen sources. Amylase(s) production in the controlled environment of a Table-Top glass Jar Fermenter (2-L capacity) was 4.8 and 5.1 units for B. theobromae and R. oryzae, respectively using CSR as the carbon substrate. It is concluded that CSR, a cheap agricultural waste obtained after starch extraction from cassava could replace soluble starch as carbon substrate for commercial production of fungal amylase(s).     

Thermotolerance and heat-shock protein expression in Northeastern Pacific<Emphasis Type="Italic"> Nucella</Emphasis> species with different biogeographical ranges

We investigated physiological traits responsible for determining the tide-height and latitudinal distributions of Northeastern Pacific Nucella congeners. First, we determined the thermotolerances of two species of intertidal dogwhelks, N. ostrina and N. canaliculata, which co-occur on the Oregon coast. We found that N. ostrina, which are distributed higher on the shore, and thus experience higher habitat temperatures, than N. canaliculata, had correspondingly higher heat-coma temperatures. Second, we acclimated individuals of all five Northeastern Pacific Nucella congeners to a common temperature and determined their thermotolerances, measured as recovery from thermal exposure, after a 5-day, 3-week, and 7-week acclimation period. The south-latitude (N. emarginata) and mid-latitude (N. ostrina) high-intertidal species were more thermotolerant than the mid-latitude low-intertidal (N. canaliculata and N. lamellosa) and north-latitude high-intertidal (N. lima) species. The results of these two experiments suggest that temperature plays a role in determining the tide-height and latitudinal distributions of these Nucella species. Finally, we measured total and inducible levels of an evolutionarily conserved and ecologically relevant protein, the 70-kDa heat-shock protein (Hsp70), which has been found to confer thermotolerance in model laboratory organisms. The results showed that the level of total, not stress inducible, Hsp70 was a better predictor of thermotolerance and that there were species-specific differences in the relationship between Hsp70 expression and thermotolerance. We suggest that Hsp70 expression may be important in conferring thermotolerance in Nucella species in nature and that higher levels of molecular chaperones may underlie increased thermotolerance between conspecifics.Communicated by P.W. Sammarco, Chauvin     

Variations in cardiac performance and heat shock protein expression to thermal stress in two differently zoned limpets on a tropical rocky shore

Understanding variation in physiological adaptations to thermal stress is vital when investigating intertidal species?? distribution patterns. The thermal sensitivities of two limpets, Cellana grata and C. toreuma, differed in accordance with their vertical distributions. Cardiac performance was maintained at higher temperatures (~47°C) for the high-zone C. grata than the mid-zone C. toreuma (~42°C). At 40°C, C. grata maintained regular heart function for ~4?h, while heart function of C. toreuma decreased rapidly. Heat shock protein expression revealed that C. toreuma had two constitutive isoforms, Hsp77 and Hsp72, and C. grata one inducible form, Hsp75, which was upregulated at 40°C, suggesting C. grata has a more effective heat shock response than C. toreuma. The temperature-adaptive differences in cardiac thermal tolerance and Hsp expression match observed differences in thermally induced mortalities with the onset of summer and may help predict differential effects of climate change on the two congeners.     

Effect of temperature on growth and reproduction of the epigeic earthworm,Eudrilus Eugeniae (Kinberg)

Influence of temperature on growth and reproduction of Eudrilus eugeniae has been investigated by laboratory culturing at regulated 25.0 degrees C, 30.0 degrees C, 37.5 degrees C and 40.0 degrees C and in fluctuating (22.7-27.3 degrees C) room temperature of prevailing (winter) season over 16 weeks. All worms died during first and tenth week at 40.0 degrees C and 37.5 degrees C respectively. Weight (biomass) and growth of worms cultured at different temperature varied significantly (P<0.01). The mean growth (mg/g live weight/day) at 25.0 degrees C., 30.0 degrees C, 35.0 degrees C, 37.5 degrees C and in fluctuating temperatures was 1,074.04 +/- 6.07, 1,554.01 degrees 192.37, 148.1 +/- 15.28, 192.83 +/- 25.8 and 1450.4 +/- 162.1 respectively. Growth declined after maturity drastically with coccon production. At 25.0 degrees C though worms are sexually mature, they failed to produce cocoons within 16 weeks whereas, at 35.0 degrees C and 37.5 degrees C they did not sexually mature. Worms attained sexual maturity at a mean weight of about 1000 mg/worm. The mean per cent maturity was higher and earlier in fluctuating temperatures and at 30.0 degrees C than at 25.0 degrees C. Cocoon production was observed only at 30.0 degrees C and in fluctuating temperatures with a mean of 0.9 and 1.5 cocoons/ wom/week and the cumulative cocoon number of 10.8 and 14.7/worm over 16th week respectively. The fluctuating temperature of uncontrolled room environment and 30.0 degrees C were favorable for various life activities of the worms. Eudrilus eugeniae appears to have range of temperature optima more than 25.0 degrees C and less than 28 degrees C. The climatic conditions prevailing in whole of the peninsular India during winter season are favourable for employing this worm in intensive field scale vermiculturing practices.     

Effect of heat stress on polyamine content and protein pattern in Skeletonema costatum

In the present paper we investigated the polyamine content and protein expression pattern in laboratory-reared Skeletonema costatum (Grev.) Cleve under temperature stress conditions. Putrescine, spermidine and to a lesser extent spermine were present in this alga. Free putrescine and spermidine increased after heat shock while a concomitant decrease in trichloroacetic acid (TCA)-soluble bound putrescine and spermidine occurred. After 40 min of 30 °C stress both were no longer detectable, whereas TCA-soluble bound spermine was present. The appearance of 83, 42, 40.7 and 35 kDa polypeptides was observed when S. costatum cells were subjected to heat treatment. Western blotting experiments revealed the presence in this diatom of ubiquitin and ubiquitin conjugates. Heat stress strongly increased the number of ubiquitin conjugate polypeptides of high molecular weight. No variation in the carbohydrate content was observed in response to stress. A possible role for these different metabolic events in the adaptive response of S. costatum to rapid temperature shifts has been hypothesized.     

Effective method for extraction of larvicidal component from leaves of Azadirachta indica and Artemisia annua Linn

Leaves of Artemisia annua linn. and Azadirachta indica were extracted in petroleum ether and hexane respectively by different methods of extraction i.e. cold extraction, reflux extraction and soxhlet extraction. The crude extract obtained was tested against third instar larvae of Anopheles stephensi. On comparison of larval mortality of crude extract obtained by these three methods, both soxhlet and reflux extraction method showed 100% mortality at 200 ppm after 48 hr in case of A. annua. However LC50 (20 ppm) value of crude extract obtained by soxhlet extraction showed better results than reflux extraction (35 ppm) method after 72 hr. In case of A. indica, crude obtained by soxhlet showed 100% mortality (after 48 hr) at 250 ppm and LC50 of 69 ppm at 72 hr. Reflux extraction does not show any appreciable mortality even at 250 ppm concentration.     

Seed germination of three provenances of Pinus brutia (Ten.) as influenced by stratification, temperature and water stress

Seeds from three provenances of Pinus brutia were stratified for 0 or 45 d (days) at 4 +/- 1 degrees C and then germinated at 15 degrees C or 20 degrees C on filter paper saturated with polyethylene glycol solutions to provide water potentials of 0, -0.2 and -0.4 MPa (mega Pascal). Regardless of stratification, germination was lower at 15 degrees C than 20 degrees C for seeds of all provenances. Stratification significantly increased germination percentage at all water potentials regardless of the germination temperatures. Lowering the water potential to -0.4 MPa reduced germination for all three provenances in unstratified and stratified seeds when averaged for two temperatures, but reaction to the increased water stress was different among the provenances. Combined over two temperatures, stratified or unstratified seeds from the highest elevation (Cehennemdere) had the lowest germination performance at all water potentials, and stratified and nonstratified seeds from a coastal elevation (Silifke) had the highest germination parameters at the lowest water potential (-0.4 MPa). It might be concluded that seed germination and resistance to water stress vary according to provenance and stratification.     

Evaluation of hemopoietic responses in Labeo rohita Hamilton following acute copper toxicity

Fish are often exposed to highly contaminated water, especially in areas where the dilution rate of waste water is low. Environmental pollutants or other stress may affect one or more of the immunological functions in fish. Effective control of toxic substances is essential for the success of fish culture, which requires fish health monitoring using biomarkers. This study evaluated the effects of heavy metal copper (Cu) at environmentally relevant concentrations on the hematopoiesis in Labeo rohita. L. rohita fingerlings were exposed to different Cu concentrations for 6, 24, 48, or 72 hr. Following exposure, percentage blast cells was found to be increased after 6 and decreased after 24, 48, and 72 hr both at sublethal and LC₅₀ concentrations, whereas percentage mature erythrocytes decreased after 6 and increased after 24, 48, and 72 hr. Erythropoietic and leukopoietic efficiencies were also affected upon exposure. Erythropoietic and leucopoietic efficiencies increased markedly after 6, 24, and 48 hr but decreased after 72 hr in sublethal-treated fish. Erythropoietic efficiency decreased significantly after 6, 24 and 48 hr but increased after 72 hr in LC₅₀-treated fish. Leukopoietic efficiency decreased significantly after 6 hr exposure and increased after 24 and 48 hr but decreased after 72 hr. Flow cytometric studies of head kidney cell cycle phase distribution revealed cell death and DNA synthesis. The percentage cell death increased in fish exposed to sublethal concentrations and rose further at LC₅₀ during the earlier hours of exposure. Synthesis of DNA was increased at sublethal concentrations but was significantly reduced at LC₅₀ dose.     

Larval period and its influence on post-larval life history: comparison of lecithotrophy and facultative planktotrophy in the aeolid nudibranch Phestilla sibogae

The variable duration of the pelagic phase of metamorphically competent larvae of benthic marine invertebrates is set by an interaction between environmental factors and larval traits that together influence the chance that a larva will encounter and respond to a suitable settlement site. In the Hawaiian aeolid nudibranch Phestilla sibogae Bergh, an extended competent larval phase resulted in a cascade of negative effects on larval and post-larval life-history traits. When raised as fed (i.e., facultatively planktotrophic) larvae, an extended larval period resulted in lower larval survival, slightly lower metamorphic success, and delayed reproduction. When raised as unfed (i.e., lecithotrophic) larvae, an extended larval period resulted in lower larval and post-larval weights, survival, metamorphic success, and reproductive output, and also resulted in a longer juvenile period and delayed reproduction. The chance nature of locating a settlement site generally spreads these negative effects over all larvae of a cohort, and so balances the relative fitness of the genetic lineages within a population.     

Population dynamics of the tropical cladoceran Ceriodaphnia rigaudi Richard, 1894 (Crustacea: Anomopoda). Effect of food type and temperature

The knowledge of population effects of food on tropical, filter-feeding cladocerans is scarce because a reduced number of species has been extensively studied. Ceriodaphnia rigaudi Richard 1894, a small-sized cladoceran distributed mainly in tropical and subtropical regions of the world, was studied. The aim of this study was to contribute to the knowledge of the reproductive biology of a poor-known Cladoceran; for this we assessed the effect of feeding and temperature on the reproduction and life cycle of this species. Three microalga species (Pseudokirchneriella subcapitata, Ankistrodesmus falcatus, and Chlorella vulgaris) were supplied as food each at a concentration of 12 mg l(-1) (dry weight, equivalent to 1.3 x 10(6), 0.4 x 10(6) and 1.35 x 10(6) cell m1(-1), respectively, and equivalent to 7.8 microg C ml(-1), at two temperatures (20 and 25 degrees C). We evaluated, among other responses, longevity, total progeny, survival, life expectancy at birth and fecundity. Organisms fed with the microalgae A. falcatus and P subcapitata presented both higher longevity (30.7 +/- 5.91, 26.6 +/- 3.59 days, respectively) and total progeny (45 +/- 13.80, 40.7 +/- 0.66 neonates female (-1) values than those organisms fed C. vulgaris (13.5 +/- 4.63 days and 17.6 +/- 6.19 neonates female (-1), respectively). On the other hand, temperature affected significantly the population parameters of C. rigaudi, recording maximal longevity values (56.1 +/- 9.41 days) at 20 degrees C in organisms fed A. falcatus; however, age at first reproduction and total progeny were negatively affected by this temperature: sexual maturation of the females was delayed until the age of 16 days and the number of neonates produced was smaller (9.8 +/- 3.45 with C. vulgaris; 24.7 +/- 6.01 with P subcapitata, and 35.5 +/- 8.59 neonates female(-1) with A. falcatus). The best reproductive responses for C. rigaudi in this study were obtained with A. falcatus at degrees 25 degrees C.     

Traits, not origin, explain impacts of plants on larval amphibians

Managing habitats for the benefit of native fauna is a priority for many government and private agencies. Often, these agencies view nonnative plants as a threat to wildlife habitat, and they seek to control or eradicate nonnative plant populations. However, little is known about how nonnative plant invasions impact native fauna, and it is unclear whether managing these plants actually improves habitat quality for resident animals. Here, we compared the impacts of native and nonnative wetland plants on three species of native larval amphibians; we also examined whether plant traits explain the observed impacts. Specifically, we measured plant litter quality (carbon : nitrogen : phosphorus ratios, and percentages of lignin and soluble phenolics) and biomass, along with a suite of environmental conditions known to affect larval amphibians (hydroperiod, temperature, dissolved oxygen, and pH). Hydroperiod and plant traits, notably soluble phenolics, litter C:N ratio, and litter N:P ratio, impacted the likelihood that animals metamorphosed, the number of animals that metamorphosed, and the length of larval period. As hydroperiod decreased, the likelihood that amphibians achieved metamorphosis and the percentage of tadpoles that successfully metamorphosed also decreased. Increases in soluble phenolics, litter N:P ratio, and litter C:N ratio decreased the likelihood that tadpoles achieved metamorphosis, decreased the percentage of tadpoles metamorphosing, decreased metamorph production (total metamorph biomass), and increased the length of larval period. Interestingly, we found no difference in metamorphosis rates and length of larval period between habitats dominated by native and nonnative plants. Our findings have important implications for habitat management. We suggest that to improve habitats for native fauna, managers should focus on assembling a plant community with desirable traits rather than focusing only on plant origin.     

Studies on influence of natural biowastes on cellulase production by Aspergillus niger

The objective of this study was to determine the influence of natural biowaste substrates such as banana peel powder and coir powder at varying environmental parameters of pH (4-9) and temperature (20-50 degrees C) on the cellulase enzyme production by Aspergillus niger. The cellulase enzyme production was analyzed by measuring the amount of glucose liberated in IU ml(-1) by using the dinitrosalicylic acid assay method. The substrates were pretreated with 1% NaOH (alkaline treatment) and autoclaved. The maximum activity of the enzyme was assayed at varying pH with temperatures being constant and varying temperatures with pH being constant. The highest activity of the enzyme at varying pH was recorded at pH 6 for banana peel powder (0.068 +/- 0.002 IU ml) and coir powder (0.049 +/- 0.002 IU ml(-1)) and the maximum activity of the enzyme at varying temperature was recorded at 35 degrees C for both banana peel powder (0.072 +/- 0.001 IU ml(-1)) and coir powder (0.046 +/- 0.003 IU ml(-1)). At varying temperatures and pH the high level of enzyme production was obtained at 35 degrees C and pH 6 by using both the substrates, respectively. However among the two substrates used for the production of cellulases by Aspergillus niger banana peel powder showed maximum enzymatic activity than coir powder as substrate.     

Activity and metabolism of larval Atlantic cod (Gadus morhua) from Scotian Shelf and Newfoundland source populations

Patterns of activity and metabolism were investigated in larval Atlantic cod (Gadus morhua L.) between December 1991 and July 1992: (1) throughout larval development; (2) between two genetically discrete populations (Scotian Shelf and Newfoundland) and (3) as a function of two different culture temperatures. During the yolk-sac stage (0 to 5 d post-hatch), changes in swimming speed were not related to mass-specific metabolic rates; no portion of the mass-specific oxygen consumption could be explained by changes in activity. In the mixed feeding stage (6 to 14 d posthatch), there was a tendency for oxygen consumption to be related to changes in swimming speed. In the exogenous feeding stage (>14 d post-hatch), oxygen consumption significantly increased with swimming speed. These ontogenetic patterns of activity and metabolism were the same for larvae from the Scotian Shelf and Newfoundland populations. However, over the entire larval life and among ontogenetic stages, the metabolic cost of activity (mass-specific O₂ consumption/swimming speed) of Scotian Shelf larvae was significantly higher than that of Newfoundland larvae. When cod larvae, that had developed at 5°C, were acutely exposed to 10°C, Scotian Shelf larvae had a higher intrinsic cost of activity than Newfoundland larvae, over the entire larval life. During the exogenous feeding stage, the mean metabolic cost of activity for Newfoundland larvae raised at 10°C and tested at 10°C was significantly higher and more variable than that of larvae raised at lower temperatures. However, the metabolic cost of activity of larvae raised and tested at 10°C was not significantly different between source populations. Together these findings suggest that differences in swimming energetics reflect changing energy requirements for activity among ontogenetic stages, and reflect adaptation to regional environments among genetically discrete populations.     

Effect of intraspecific density on life history traits and population growth rate of Neanthes arenaceodentata (Polychaeta: Nereidae) in the laboratory

The effects of intraspecific density on life history traits and population dynamics of the nereid polychaete Neanthes arenaceodentata Moore were assessed in a laboratory experiment. Survival, growth, and fecundity were measured for one generation of worms at densities of 40, 80 and 160 worms per 840 cm² (1x, 2x, and 4x treatments, respectively). Density did not affect size (prior to pairing), percentage of worms paired, time to pairing, or size of mature paired males. Density did have a significant negative effect on survival, size of mature paired females, time to spawning, percentage of females that reproduced, and number of eggs per reproducing female. As density increased, mean survival was 90.0, 80.8 and 74.0%; mean size of mature females was 52.2, 49.2 and 48.1 segments; mean time to spawning was 100.6, 102.4 and 109.4 d; and mean fecundity was 881, 622, and 598 eggs per female, for 1x, 2x and 4x treatments, respectively. Increased density reduced the potential population growth rate, ; for a given rate of larval survivorship, was lower in the 2x and 4x treatments than the 1x treatment. Analysis of sensitivity of to changes in survivorship indicated that population growth rate at the highest density was sensitive to both changes in larval survivorship and the probability of producing a successful brood, although at low densities, was sensitive only to changes in larval survivorship. We attribute these density effects to aggressive bahavioral interactions between the worms, primarily the adults. This experiment identifies key life history traits that could be measured in future experiments to test population level responses of N. arenaceodentata populations to pollutants, both in the laboratory and in the field.Contribution No. 820 of the U.S. Environmental Protection Agency, Environmental Research Laboratory and Contribution No. 189 of the Marine Sciences Institute, University of Connecticut     

Rate of heat dissipation by gametes and larval stages of Mytilus edulis

Heat dissipation of sperm, eggs and various stages of the planktonic larvae of the mussel Mytilus edulis L. was recorded directly at 15°C. The absolute heat dissipation increased steadily over all stages examined. The massspecific heat dissipation also increased during early embryogenesis from the fertilized egg to the D-larval stage. Starting from the early veliconcha stage, however, the mass-specific rate of heat dissipation declined from about 90 m W g^-1 with increasing body size with a weight exponent of-0.35. A comparison with literature data revealed a consistently higher metabolic activity than previously estimated by indirect calorimetry for gametes and larvae.     

Metabolic and molecular stress responses of the gilthead seabream Sparus aurata during long-term exposure to increasing temperatures

Tolerance to a changing climate regime and persistence in the natural environment depends on the limited capacity to acclimate to changing temperatures. The present study aimed to identify and characterize thermal limits of the Mediterranean fish Sparus aurata as well as the processes providing heat protection during exposure to high temperatures. Processes studied included heat shock protein expression, protein kinase activity and metabolic adjustments. Molecular responses were addressed through the expression of Hsp70 and Hsp90 and the phosphorylation of stress-activated protein kinases, p38 mitogen-activated protein kinase (p38 MAPK) and cJun-N-terminal kinases (JNKs). Thermal impacts on metabolic capacities were assessed by studying the maximum activities of citrate synthase (CS), malate dehydrogenase (MDH) and 3-hydroxyacyl CoA dehydrogenase (HOAD) as well as pyruvate kinase (PK) and lactate dehydrogenase (L-LDH). The expression of Hsp70 and hsp90 was activated when the fish were exposed to temperatures beyond 20°C. Increased phosphorylation of p38 MAPK and JNKs indicated the parallel activation of MAPK signaling cascades and the potential involvement of MAPKs in the induction of Hsp genes. Exposure to extreme temperatures beyond 24°C caused an increase in the enzymatic activity of PK and LDH indicating an enhanced glycolytic potential.     

胚胎期草甘膦铵盐暴露对中华鳖幼体的表型与生理表现的影响

草甘膦是全球范围内生产与使用量最大的除草剂。虽然草甘膦制剂被分于低毒等级,但是许多研究显示其对动物的生理、行为表达具有广泛的干扰作用。本研究将中华鳖胚胎暴露于不同浓度的草甘膦铵盐溶液以评估草甘膦除草剂对其胚胎发育及孵出幼体表型及生理表现的影响。结果显示:一定浓度范围(5～5 000 mg·L~(-1))内,草甘膦铵盐对中华鳖胚胎发育速率、孵出幼体大小、游泳能力、肝脏甘油三酯含量、超氧化物歧化酶活性、丙二醛含量以及热激蛋白70 mRNA相对表达量无显著影响。结果表明:一定浓度范围草甘膦除草剂暴露对中华鳖胚胎发育的影响较小,不改变孵出幼体的表型及其生理表现。     

Induction of oxidative stress by non-lethal dose of mercury in rat liver: possible relationships between apoptosis and necrosis

Sprague Dawley strain of male rats weighing 200 +/- 10.0 g, were exposed intramuscularly to non-lethal dose of mercury for short acute duration of 24 and 48 hr. Mercury treatment increased thio-barbituric acid reactive substance (TBARS) and conjugated diene (CD) content with increase in duration when compared with control. This reflects possible increase in lipid peroxidation, revealing that sufficient intoxication was generated by non-lethal dose of mercury. Furthermore, mercury treatment decreased tissue glutathione (GSH) content to 2.07 and 1.49 microg GSH mg protein(-1) with concomitant decrease in glutathione-S-transferase (GST) activity by 26.06 and 36.40% after 24 and 48 hr of exposure respectively. The elevations of aspartate transaminase (AST) and alanine transaminase (ALT) levels measured exhibited increase of 287.5 and 214.5% after 48 hr of exposure respectively which were found to be highly significant compared with control. Western blot analysis indicated upregulation of caspase-9 and upsurge in effect or caspase-3 activity leading to apoptosis. The concluded findings of the present investigation suggests possible role of early mercury exposure in inducing oxidative stress mediated apoptosis in mammalian model systems as an indicator component of environmental toxicology.     

Variation in larval life-history traits among reef fishes across the Isthmus of Panama

We tested the hypothesis that regional differences in oceanic productivity have led to the evolution of predictable patterns of regional variation in life-history traits of pelagic larvae of tropical reef fishes. To do so we compared larval traits (egg and hatchling size, larval growth rate and duration, and size at settlement) among closely related reef fishes from the Atlantic and Pacific coasts of the Isthmus of Panama. This comparison provides a control for phylogenetic effects because those regions shared a common fauna prior to the rise of the Isthmus ˜3.5 million years ago, subsequent to which each fauna evolved independently under a very different productivity regime. We measured larval traits of 12 benthic-spawning damselfishes (Pomacentridae: Abudefduf, Chromis and Stegastes) and 13 pelagic-spawning wrasses (Labridae: Bodianus, Halichoeres and Thalassoma). These included members of each genus on each side of the Isthmus and four sets of transisthmian sister species of pomacentrids. Among the pomacentrids we found consistent transisthmian differences in hatchling size, but not in other larval traits. Essentially the reverse pattern occurred among the labrids – larval growth and duration differed consistently among congeners in the two regions, but without consistent differences in hatchling size or size at settlement. Neither relationship is predicted by the regional-productivity hypothesis. Most of the differences were quite small. Stronger phylogenetic effects on larval traits (inter- and intrageneric variation within regions) occur in both families and evidently overwhelm any effect of regional variation in productivity. Reassessment of data that takes into account such phylogenetic effects questions previous conclusions about the existence of regional differences in larval traits among damselfishes in the West Pacific and the Caribbean. Received: 19 January 2000 / Accepted: 26 September 2000     

Comparative larval development of the shipworms Bankia gouldi and Teredo navalis

Larvae of Bankia gouldi (Bartsch) and Teredo navalis L. were reared in the laboratory at various temperatures and salinities. T. navalis spawned at lower temperatures than B. gouldi. T. navalis larvae were released at temperatures from 13° to 30°C; in B. gouldi, spawning occurred from 17.5° to 30°C. Both species released offspring at salinities of 20 and 30‰. Larvae of the two species can be distinguished morphometrically at the earliest pelagic veliger stage and in the pediveliger stage. Average dimensions of newly released T. navalis larvae are 88 x 75 μ (length x height), while the youngest B. gouldi veligers measure 61 x 50 μ. Pediveligers of T. navalis (205 x 239 μ) are smaller than those of B. gouldi (221 x 260 μ). At other stages of larval development the two species appear so similar that they cannot yet readily be distinguished. Under laboratory conditions of 25°C and 30 ‰, the free-swimming life of B. gouldi to the pediveliger stage was about 10 days longer than that of T. navalis (25 and 15 days, respectively). Incubated larval development of T. navalis was estimated to be 5 days at 25°C. Potential competition between larval stages of the two species, and modification of settling behavior by dissolved humic material (Gelbstoff), is discussed.