Spawning migration and returning behavior of white-streaked grouper Epinephelus ongus determined by acoustic telemetry

White-streaked grouper (Epinephelus ongus) is an important fishery target that forms fish spawning aggregations (FSAs) at specific spawning grounds. The aims of the present study were to investigate migration behavior and returning behavior in terms of FSA using acoustic telemetry. Among the 30 specimens tracked, three types of movement pattern were observed: type 1, high site fidelity at the release area before the spawning period, migration to the spawning ground during the spawning period and return to the release area just after the spawning period (17 specimens); type 2, high site fidelity at the release area, disappearance from the area during the spawning period but was not detected at the spawning ground and return to the release area (8 specimens); and type 3, high site fidelity at the release area was observed before, during and after the spawning period (5 specimens). For the 17 specimens that were categorized into type 1, the dates of departure from their release area and the dates of return to the release area of males were, respectively, significantly earlier and later than those of females. The duration between the departure date and the return date (“duration away”) of males was significantly longer than that of females. The duration away tended to be positively related to the condition factor. All 25 specimens that were categorized as type 1 and type 2 showed returning behaviors to the release area.     

Assessment of microhabitat preferences in juvenile dusky grouper (Epinephelus marginatus) by visual sampling

As a top-level predator, the brown grouper Epinephelus marginatus can play an important role in maintaining the ecological balance of hard-bottom ecosystems. However, to fulfil this role, the species must have a sufficient population density and a wide size range. The presence of such a "healthy" grouper population is one of the known benefits of the protection measures applied to marine protected areas. The availability, in marine reserves, of areas suitable for settlement and recruitment of early juveniles can contribute to preserving a well-structured population. Thus, knowledge of microhabitats preferred by juvenile groupers is an important step in locating, within protected or not yet protected areas, nursery sites that might need a specific protection regime. The aim of the present work was to evaluate habitat and microhabitat preferences of juvenile E. marginatus, in comparison with two other serranids of comparable size, Serranus cabrilla and S. scriba, in the marine reserve of Ustica Island (SW Mediterranean). At different sites, located along the shallow coastal area of the reserve, 329 individuals of the three serranid species were visually surveyed by means of skin- or SCUBA-diving in June 1999. The location of each encountered fish was characterised by both biotic and abiotic variables evaluated at two spatial scales. In order to assess interspecific differences in the use of the spatial environment, the results were analysed by correspondence analysis. According to observations on a small spatial scale, juvenile groupers showed a preference for cavities and recesses, in clear contrast with both Serranus species. When out of such sheltered places, juvenile groupers avoided visually exposed locations (convex substrates and very large visual fields), preferring flat or sub-horizontal rocky substrates. Conversely, S. scriba, and especially S. cabrilla, chose rather open microhabitats (flat to convex substrates, with large to very large visual fields). On a larger spatial scale, brown groupers and the two other serranids showed no marked differences in their habitat preferences.     

Relative growth and production of the estuary grouper Epinephelus salmoides under different stocking densities in floating net-cages

Studies on the relative growth and production of the estuary grouper Epinephelus salmoides Maxwell were conducted in floating net-cages at 5 different stocking densities to determine the optimal level for stocking for commercial culture. The fish were stocked at densities of 15, 30, 60, 90 and 120 fish per m³, and reared for a period of 8 months. Results of the present study indicated that fish stocked at a density of 60 fish m^-3 grew equally fast and showed a food conversion ratio, mortality rate, and condition factor comparable to those at the lower stocking densities of 15 and 30 fish m^-3. At the end of the experiments, net-yield and production at this level of stocking density (60 fish m^-3) were not significantly different from those at the higher stocking densities of 90 and 120 fish m^-3, but showed increases of 86.7% over those at a stocking density of 30 fish m^-3 and 294.2% over those at a stocking density of 15 fish m^-3. The stocking density of 60 fish m^-3 is therefore taken as the optimal stocking rate for economical production of estuary groupers in floating net-cages. The estuary groupers take 7 to 8 months to grow from 15–16 g to marketable size (>500 g) at a stocking density of 15 fish m^-3, 8 to 9 months at a stocking density of 30 to 60 fish m^-3 and 11 to 12 months at 90 to 120 fish m^-3.     

Genetic structure of camouflage grouper,<Emphasis Type="Italic"> Epinephelus polyphekadion</Emphasis> (Pisces: Serranidae), in the western central Pacific

The objective of the present study was to investigate the population genetic structure of the commercially important camouflage grouper, Epinephelus polyphekadion (Bleeker, 1849), in the western and central Pacific Ocean to improve existing management. Camouflage grouper are widely distributed in the Indo-Pacific and form brief, seasonal, spawning aggregations that are often heavily fished. The present study examined populations sampled in 1997-1998 at five sites in the western central Pacific spanning a geographic distance of ~5,000 km: New Caledonia, Great Barrier Reef, Palau, Marshall Islands, and Pohnpei (Micronesia). Primer pairs were developed to examine genetic variation at three polymorphic microsatellite loci. Cluster analysis, using genetic distance, revealed three regional groupings: (1) Palau, (2) Pohnpei and the Marshall Islands, and (3) the Great Barrier Reef and New Caledonia. Highly significant allele frequency differences were observed among sites. At Pohnpei, significant allele frequency differences in successive years were also apparent, possibly related to genetic variation among cohorts or between local spawning groups. The inter-annual differences at Pohnpei suggest that there may be further genetic structuring over relatively modest distances, a finding relative to determining management units for this commercially valuable species and suggests that future studies need to incorporate possible small-scale temporal or spatial components into study design.     

Sexual reproduction in Acropora (Isopora) (Coelenterata: Scleractinia)

In contrast to the seasonal gamete and planula production of Acropora (Isopora) palifera on Heron Island reef (Lat. 23° S), populations on Lizard Island reef (Lat. 14° S), sampled in 1979, 1981 and 1983, and Salamaua and Busama reefs (Lat. 7° S), sampled from 1980 to 1983, planulated year-round. Intensive sampling of colonies at Salamaua and Busama showed that gametes ripened at two-month intervals and that up to six cycles of gametes and larvae could be produced by an individual colony. Gametes of only a portion of the population — usually close to 50% — ripened each month. The Salamaua population, on average, produced fewer and smaller planulae than the Heron Island population during each two-monthly reproductive cycle. Hypotheses correlating the annual periodicity of breeding in marine animals with latitudinal variation of temperature were tested. In general, the time of breeding in A. palifera at Heron Island reef is much more restricted than theories based on latitudinal variations of water temperature would predict. It is hypothesized that, in the near subtropical environment of Heron Island reef, this species has evolved a life-history strategy that limits the amount of energy allocated to reproduction and allocates more energy to growth.     

Early signs of recovery of Acropora palmata in St. John,US Virgin Islands

Since the 1980s, diseases have caused significant declines in the population of the threatened Caribbean coral Acropora palmata. Yet it is largely unknown whether the population densities have recovered from these declines and whether there have been any recent shifts in size-frequency distributions toward large colonies. It is also unknown whether colony size influences the risk of disease infection, the most common stressor affecting this species. To address these unknowns, we examined A. palmata colonies at ten sites around St. John, US Virgin Islands, in 2004 and 2010. The prevalence of white-pox disease was highly variable among sites, ranging from 0 to 53 %, and this disease preferentially targeted large colonies. We found that colony density did not significantly change over the 6-year period, although six out of ten sites showed higher densities through time. The size-frequency distributions of coral colonies at all sites were positively skewed in both 2004 and 2010, however, most sites showed a temporal shift toward more large-sized colonies. This increase in large-sized colonies occurred despite the presence of white-pox disease, a severe bleaching event, and several storms. This study provides evidence of slow recovery of the A. palmata population around St. John despite the persistence of several stressors.     

Sexual reproduction in Acropora (Isopora) species (Coelenterata: Scleractinia)

Despite the wide range of morphological diversity among the Acropora (Isopora) colonies on Heron Island (Great Barrier Reef, Australia), only two reproductively isolated species were present from 1977 to 1982: A. cuneata (Dana, 1846) and A. palifera (Lamarck, 1816). Both species released planulae lacking zooxanthellae and were simultaneous hermaphrodites with testes and ovaries occurring on separate mesenteries within the same polyp. Oogenesis preceded spermatogenesis. Seasonal cycles of gametogenesis, embryogenesis and planulation occurred in the two species. Colonies of A. cuneata developed two cycles of gametes. One cycle matured near the first quarter moon in April and the other on the same lunar phase in June. Planulae release occurred from about September to December each year and was not correlated with lunar phase. Gametes of A. palifera ripened only once per annum, a few days after the last quarter moon in November, and planulation occurred from about January to March. Embryos were brooded in the coelenteron of the polyps in both species. Ova were fertilized in the mesenteries and embryos were retained within an envelope of mesoglea and gastrodermis, remaining attached to the mesentery by a stalk until the larvae matured and were released. A. palifera and A. cuneata were abundant in the unpredictable reef flat environment. However, their life-history traits, e.g. seasonal reproduction, delayed sexual maturity, large colony size and fairly long life span, were more specialised than had been predicted for this type of environment.     

Alloimmune responses between Acropora hemprichi conspecifics: nontransitive patterns of overgrowth and delayed cytotoxicity

Allogeneic interactions between Acropora hemprichi (Ehrenberg) colonies were followed in situ up to 18 mo between 1990 and 1992 in Eilat, Red Sea. We established all 21 possible branch pair combinations among seven large colonies in three to eight replicates each (n=92 pairs), in addition in 14 pairs of grafts within-colonies. All isografts resulted in fusion. Allogeneic interactions revealed a variety of effector mechanisms which involved the appearance of dark blue-purple color in the tissues of interacting branch tips (<1 cm), unilateral overgrowths (1.0 to 1.5 mm mo^-1 for 1 to 8 mo), rejections, healings, continuous overgrowths, reversals, repeated rejections and more. Direction of overgrowth was usually specific to a given combination of colonies. A hierarchial network of overgrowths was obtained by analyzing overgrowth directions of all pairwise combinations, which included 30 transitive and five nontransitive three-way combinations. These outcomes, similarly to responses of allogeneic encounters recorded from other coral species, show that colonies can respond selectively to different types of allogeneic challenges. It is suggested that corals may have the capacity to distinguish self from nonself by recognizing nonself attributes presented on conspecifics.     

Compartmentation and turnover of organic carbon in the Staghorn coral Acropora formosa

Four colonies of Acropora formosa were incubate with Na₂ ¹⁴CO₃ for separate 2 h periods within a 24 h period, and then returned to the reef from which they were collected. Terminal branches were collected at intervals over the following 5 d and analysed for radioactivity associated with the skeleton and certain organic pools. Colonies incubated at night showed little or no loss of fixed radioactivity during the 5 d on the reef. However, 50–60% of photosynthetically-fixed ¹⁴C was lost from the terminal branches during the first 40 h on the reef. This loss of radioactivity probably resulted from release of mucus and dissolved organic carbon from the coral tissues. Most of the loss of photosynthetically-fixed ¹⁴C was due to decrease in the radioactivity of lipids (80% of the total ¹⁴C loss) and methanol-water soluble compounds. Determination of any sequencing in metabolic compartments was made difficult by the rapidity with which ¹⁴C dissappeared from most of the metabolic pools measured. ¹⁴C was incorporated into the skeleton throughout the 5 d on the reef, although the rate of incorporation was very low in colonies which had been incubated with Na₂ ¹⁴CO₃ at night.     

Ichthyotoxicity found in cultured media of Protogonyaulax spp.

Ichthyotoxicity was observed in the cultured media from Protogonyaulax catenella and P. tamarensis. No paralytic shellfish poison was detected in the cultured media. Test fish in the cultured media died showing signs of hypoxia. Histological observations of the gills of intoxicated fish indicated that the epithelial cells were swollen and exfoliated from the pillar cell. The cultured media had hemolytic activity against erythrocytes of various animals. The media also decreased the elasticity of eggs of rainbow trout Salmo gairdneri. From these results, it is concluded that the cultured media of both species of Protogonyaulax contain a cytotoxin which is lethal to fish.     

Planning for persistence in marine reserves: a question of catastrophic importance.

Large-scale catastrophic events, although rare, lie generally beyond the control of local management and can prevent marine reserves from achieving biodiversity outcomes. We formulate a new conservation planning problem that aims to minimize the probability of missing conservation targets as a result of catastrophic events. To illustrate this approach we formulate and solve the problem of minimizing the impact of large-scale coral bleaching events on a reserve system for the Great Barrier Reef, Australia. We show that by considering the threat of catastrophic events as part of the reserve design problem it is possible to substantially improve the likely persistence of conservation features within reserve networks for a negligible increase in cost. In the case of the Great Barrier Reef, a 2% increase in overall reserve cost was enough to improve the long-run performance of our reserve network by >60%. Our results also demonstrate that simply aiming to protect the reefs at lowest risk of catastrophic bleaching does not necessarily lead to the best conservation outcomes, and enormous gains in overall persistence can be made by removing the requirement to represent all bioregions in the reserve network. We provide an explicit and well-defined method that allows the probability of catastrophic disturbances to be included in the site selection problem without creating additional conservation targets or imposing arbitrary presence/absence thresholds on existing data. This research has implications for reserve design in a changing climate.     

Ultrastructure of sperm and spermathecae in Micromaldane spp. (Polychaeta: Capitellida: Maldanidae)

Assessing the possibility that external fertilization has re-evolved requires the study of monophyletic groups that exhibit various reproductive methods. Maldanid polychaetes show a range of reproductive mechanisms, though previous studies of reproduction have hitherto been restricted to larger species with external fertilization. Micromaldane pamelae Rouse and M. nutricula Rouse are small, gonochoristic maldanids that brood directly developing larvae. Both species have sperm with elongate nuclei and an acrosome extending down each side of the anterior end of the nucleus. A true midpiece is absent; two mitochondria extend along the posterior region of the nucleus. Spermatids develop synchronously in large clusters connected by a cytophore. In M. pamelae sperm are released into the water as spermatozeugmata. These are comprised of clusters of sperm with their tails oriented to the centre and the sperm heads facing outwards. Females of M. pamelae and M. nutricula bear pairs of spermathecae ventrally (M. pamelae three pairs, between setigers 10 and 11, 11 and 12 and 12 and 13 and M. nutricula two pairs, between setigers 10 and 11 and setigers 11 and 12). The blind sacs are epidermal invaginations bound closely together. The entrance to each spermatheca may only be 1 to 2 m across with each spermatheca holding several hundred sperm. This represents the first detailed study of spermathecae in the Capitellida. The occurrence and structure of spermathecae and spermatozeugmata in other groups are discussed and compared with Micromaldane spp. Comparisons are made with non-polychaetes with the purpose of discussing functional aspects of reproductive mechanisms in marine metazoans in general. Elongate sperm nuclei are associated with sperm storage and/or large egg size. The lack of an elongate sperm midpiece may be an indicator of having to swim in water but does not contraindicate sperm storage. Spermatozeugmata may serve as an indication of sperm storage and brooding of larvae. Speculations on the phylogenetic significance of these reproductive features are limited by the fact that supposedly modified (i.e., derived) states may reflect functional/structura, constraints of small body size.     

Microhabitat segregation of the amphipod genus Gammarus (Crustacea: Amphipoda) in the Northern Baltic Sea

Closely related species may occupy very similar niches but are often found to diverge by one or more traits when they share the same habitat. Five indigenous and sympatric Gammarus species are characteristic for the Baltic rocky littoral ecosystem. Yet, the species-specific distribution of these sympatric gammarids has not been well studied in the northern Baltic Sea. This study was undertaken to assess the spatial distribution of gammarid amphipods along wave exposure and depth gradients to study whether they show segregation in their microhabitat use. We sampled 12 rocky sublittoral shores along a wave exposure gradient over a period of 5 years. Samples differed with respect to depth and macroalgal type. Three of the five gammarid species occurred mainly in different depth zones and among different macroalgae at the exposed shores. In contrast, on protected shores, where algal zonation is weaker, a link to zonation and macroalgal type was almost absent. Moreover, the microhabitat use was strongest during the reproductive seasons of the species. The observed microhabitats of the three gammarid species fit well to their species-specific mean body sizes.     

Histology of Sculpin spp. in east Greenland. I. Histological measures

There is inadequate morphological nomenclature and definition of organ pathology when using wild fish in biomonitoring of environmental pollution. The aim of this investigation was to provide a guide that assesses histology of Shorthorn (Myoxocephalus scorpius) and Fourhorn (Myoxocephalus quadricornis) sculpins obtained from a study using these two fish species as bioindicator organisms to evaluate environmental impact attributed to a dumpsite located in East Greenland. Specific histopathological lesions were quantified on the basis of Bernet et al. and all lesions were photomicrographed, evaluated, and placed into specific categories of five reaction patterns. These were circulatory disturbances, regressive changes, progressive alterations, inflammation, and tumors based on anatomical location, type, and severity. This method is postulated to enable an objective assessment of the histological integrity of fish gills and liver; thus, making it possible to compare sculpin pathology and reaction patterns at different locations. Data suggest that this updated histological guide might be used for identification and quantification of histological lesions when applying sculpins in biomonitoring programs in Greenland and other Arctic regions.     

Evolutionary genetics of marine Mysis spp. (Crustacea: Mysidacea)

Inter-and intraspecific allozyme differentiation in the mysid crustacean genus Mysis in the North Atlantic region was studied in order to evaluate earlier concepts of evolutionary and systematic relationships and to assess patterns of subdivision within widespread taxa. The results support a relatively ancient divergence of the marine and non-marine species of the genus, and are generally in line with the current subgeneric tridivision into Mysis s.str., Michteimysis and Auricomysis. However, the North American littoral species M. gaspensis should be returned to subgenus Mysis s.str. from its present position in Michteimysis with M. mixta. The closest observed affinities within Mysis s.str. were between M. gaspensis and the freshwater M. relicta group, and between M. oculata and M. litoralis. Intraspecific differentiation among North European coastal populations of M. oculata and M. litoralis was moderately strong (F _ST0.1), suggesting population bottlenecks and limited dispersal in the post-glacial time. On the other hand, ransoceanic differences were not essentially greater, indicating the systematic homogeneity and long-term dispersal capacity in the marine species. This contrasts with the strong genetic and systematic fragmentation earlier found within the circumboreal M. relicta species group.     

Vertical heterogeneity in physiological characteristics of Ulva spp. mats

In eutrophic areas, green macroalgae are frequently and for long periods arranged in mats, resulting in a steep light gradient. This study investigates the effect of this gradient on physiological characteristics [tissue nitrogen content, maximal photosynthetic efficiency (F_v/F_m), glutathione levels and redox ratio, absorbance and absorption spectra] of the green macroalga Ulva spp. Mats were sampled during the build-up (June), stationary (July), and decomposing (September) phases of a macroalgal bloom in the Veerse Meer, a eutrophic brackish (salinity 15–20 psu) lake in the southwest Netherlands. Water samples were taken for nutrient analyses. At all three sampling dates, the mats were composed almost entirely of Ulva spp.; in September the mats were in decay and covered with silt and epiphytes. In June and July, total dissolved inorganic nitrogen concentration (DIN) of the water within the mat was significantly higher than outside the mat. Pronounced vertical differences were found in tissue N, F_v/F_m values, total glutathione levels, glutathione redox ratios, and absorbance. In June and July, tissue N decreased from over 2.2% dry weight (DW; N-sufficient) in the bottom layers to around 1% DW (minimum level for survival) in the top layers. Wide-band absorption increased with depth in the mat and throughout the season, probably due to higher Chl a and b and lutein contents. The shape of the absorption spectrum was similar for all layers. The absorption of the silt/epiphyte film on the top Ulva layer was highest; its absorption spectrum (high absorption in the 500–560 nm range) indicates that the film on the top layers of the macroalgal mats mainly consisted of diatoms. In June, F_v/F_m and the glutathione redox ratio of the algae increased with depth in the layer, while total glutathione decreased. Low F_v/F_m values in the bottom and middle layers in September reflect the bad condition of the algae; the mats were largely decaying. It is concluded that multiple growth-limiting gradients occur in macroalgal mats: upper layers suffer from nitrogen limitation and photoinhibition while bottom layers are light limited. The algae in the mat acclimatize to low light conditions by increasing their absorption through increased pigment contents and by higher photosynthetic efficiency during the build-up and stationary period. This study qualifies the glutathione redox ratio as a promising candidate for stress indicator in macroalgae and provides suggestions for its further development.Communicated by S.A. Poulet, Roscoff     

Genetic structure and distribution ofPhotololigo spp. in Australia

Four species ofPhotololigo were identified using allozymes from the northern waters of Australia between the North West Shelf (114°00E) and Brisbane (153°00E). Two of these species fitted the gross morphology ofP. edulis documented from Japan and two taxa shared the distinguishing features ofP. chinensis. F-statistic analyses revealed no major population genetic structuring in any of the species over the geographical range sampled and all populations were in Hardy-Weinberg equilibrium. Given that the distributions of the species appear to be correlated with depth, at least during the austral summer, this panmixia is considered to reflect extensive gene flow through longshore movement of these squid. It is suggested that depth constraints, or factors associated with depth, act as effective barriers to gene flow and, therefore, provide mechanisms for allopatric speciation in this genus. The data from northern Australia indicate that the current view thatLoligo species have broad distributions may need revision and that a number of widespread taxa (such asP. edulis andP. chinensis) are likely to comprise a series of hitherto unrecognised allopatric sibling species. Heterozygosity levels were low for all species exceptPhotololigo sp. 1, which had a restricted deep-water distribution. These data are concordant with the habitat specialist-generalist model, which is discussed.Contribution No. 654 from the Australian Institute of Marine Science     

Clam predation by whelks (Busycon spp.): Experimental tests of the importance of prey size,prey density,and seagrass cover

In 57 l-m² samples within a meadow of Halodule wrightii in Bogue Sound, North Carolina, USA, densities of the clams Mercenaria mercenaria and Chione cancellata were positively associated with seagrass cover. Where seagrass was experimentally removed, marked individuals of both clam species exhibited high rates of mortality in fine sand sediments during two successive experiments spanning 13 months. In the unaltered (control) seagrass meadow, M. mercenaria density remained constant over 13 months and C. cancellata density declined at a slower rate than in the unvegetated plots. Seagrass provides these clams with a refuge from whelk (Busycon carica, B. contrarium, and B. canaliculatum) predation, the major cause of mortality and population decline in experimentally unvegetated plots. In 2 factorial field experiments in unvegetated substratum in which densities of M. mercenaria and C. cancellata were varied independently, first over 5 levels (0 X, 1/2X, 1 X, 2 X, 4 X) and subsequently over 4 levels (0 X, 1/4 X, 1 X, 4 X), there was no repeatable intra- or interspecific effect of density on percent survival, or on the rate of any mortality type. Whelk predation fell preferentially on larger size classes of both species, whereas factors which contribute to clam disappearance usually acted more intensely on smaller sizes. Experimental exclusion of large predators by caging demonstrated that even in unvegetated substratum survivorship of both clam species was high in the absence of whelks and other predators. Individuals of C. cancellata live closer to the sediment surface than those of M. mercenaria, which may explain why seagrass does not serve as effectively to protect them from whelk predation. The mechanism of whelk inhibition may depend upon sediment binding by the H. wrightii root mat, which produces a demonstrable decrease in the physical penetrability of surface sediments.     

Aesthetascs in Lysmata spp. shrimp: sexual dimorphism and relationship with social environments

Aesthetascs are the olfactory receptor organs responsible for mate recognition in many decapod crustacean species. The number of aesthetascs varies greatly among species in different environments, but the functional significance of this variation is poorly understood. This study examined the relationship between social environment and the number of aesthetascs in six species of caridean shrimp in the genus Lysmata. Generally, the number of aesthetascs was greater in group-living species (L. boggessi and L. wurdemanni) than in low-density (L. ankeri and L. pederseni) and pair-living species (L. amboinensis and L. debelius). Aesthetascs are innervated by olfactory receptor neurons (ORNs). The total number of ORNs is related to the sensitivity of olfactory odor detection, and it was higher in group-living species than in pair-living species. Sexual dimorphism in the number of aesthetascs was present in L. boggessi, L. wurdemanni, and L. ankeri but not in L. pederseni and L. amboinensis.     

Uptake of dissolved inorganic nitrogen by the symbiotic clam Tridacna gigas and the coral Acropora sp.

Dissolved inorganic nitrogen flux was studied in the giant clam Tridacna gigas and the corals Acropora sp. and Tubastrea micrantha from the tropical reefs of Belau, Micronesia in 1983. T. micrantha, a nonsymbiotic coral, excreted ammonium. However, Tridacna gigas and Acropora sp., which contain symbiotic dinoflagellates (zooxanthellae) were able to take up both ammonium and nitrate. The requirement for a previous light exposure to sustain uptake by T. gigas is reported. The uptake kinetics of these symbioses are described and include the capacity of the zooxanthellae for surge uptake when given nutrient spikes.Contribution No. 417 of the Allan Hancock Foundation