Growth Bands Research Articles

Further observations on Archaeosphaerodiniopsis verrucosa Rampi (Dinophyceae)

The recently rediscovered dinoflagellate genus Archaeosphaerodiniopsis Rampi emend. Carbonell-Moore has been found in material from different oceans to that from where it was rediscovered. In all cases the cells were identified as Archaeosphaerodiniopsis verrucosa. Scanning electron microscopy (SEM) observations of these recently identified cells permitted completion of its description. It was confirmed that all large epithecal plates (1''–5'') have one large pore surrounded by a larger ring, except for plate 1'', which has two of these pores. Plates 2''' and 4''' lack the large pores, while the other postcingular plates and the antapical plate display the same large pore and ring. The relative position of this pore and ring on the plate was the same regardless of the geographic location where the cell was found. What was thought to be a growth band between the apical pore area and the first precingular plate was determined to be a very small separate plate, bringing the total number of apical plates to five. The number of cingular plates was confirmed to be six. All the cells of A. verrucosa observed to date, including Rampi’s, display well-developed intercalary bands, similar to those found in peridinioids, though with an overlapping plate pattern more typical of gonyaulacoids, where only the overlapping plate develops the growth band. The number of plates in the epitheca and the tabulation pattern closely resembles that of a typical gonyaulacoid (except the apical pore area), while its hypotheca is more of a peridinioid. The overlapping plate pattern matches that described in the literature for gonyaulacoids and peridinioids. A. verrucosa may be found in the Mediterranean, Central Equatorial Pacific, Coral Sea and Western Indian Ocean, in either surface or deep water. Plate tabulation formula: Po, Pt, X, 5', 6'', 6C, 4S, 5''', 1''''.

Precision of growth band determination from eyestalk sections of Antarctic krill (Euphausia superba) preserved in formalin

Abstract Age information for commercial fish species is crucial to fishery management. Age information for Antarctic krill (Euphausia superba) will be important for stock assessment modeling and future feedback management of krill fisheries. Samples stored in 70% ethanol provide an opportunity to detect the growth bands of eyestalk sections. Moreover, information derived from samples preserved in formalin will have a greater impact on the feedback management process because this preservation method was more common in previous decades. Out of 162 Antarctic krill individuals preserved in 5% formalin, the growth bands from eyestalk sections of 134 samples were readable. The relationship between the total length and the growth bands in the eyestalk was analyzed. Three main parameters, including exact percent agreement (EPA), coefficient of variation (CV), and average percentage error (APE), were used to evaluate the precision of the growth bands.Results show decreased CV and APE values and an increase in the EPA value with the accumulation of reading runs. This method is direct and uses a grinding and polishing technique before reading, contrary to Krafft et al. (2016) and Kilada et al. (2017). Combined with published studies, specimens collected from autumn to winter in this study can provide a better understanding of Antarctic krill growth. This study presents important information for age determination, particularly for specimens preserved in formalin, and will benefit the stock assessment and acoustic estimation of this species in the future. Further studies are required to validate the correlation between growth bands and age. Additionally, more samples from different seasons and regions are also needed to fully understand the growth dynamics of this species.

Effect of different combinations of precursors of zirconium and selenium in the electrodeposited ZrSe2 thin films

The article describes the effect of different combination of zirconium and selenium sources on electrodeposited ZrSe2 thin films. Three different zirconium sources; ZrO(NO3)2.H2O, Zr(SO4)2 and ZrOCl2.8H2O and two different selenium sources; SeO2 and Na2SeO3 were used. The effect of combination of zirconium and selenium sources of the films prepared by optimising the electrolyte potentials through cyclic voltammetry and their structural, compositional, surface morphology and optical properties are studied. It is noticed that the film growth rate and band gap energy is found to be sensitive to Zr sources used. All films are found to be hexagonal polycrystalline, regardless of the Zr and Se sources used.

Strong sea forcing and warmer winter during solar minima ∼2765 yr B.P. recorded in the growth bands of Crassostrea sp. from the confluence of river Ganges, Eastern India

Long term variation of solar activity plays a key role in controlling climatic oscillations during glacial-interglacial cycles. The records of such climatic shifts can be retrieved from sedimentary archives in overbank deposits found in the estuary regions of major rivers in the tropics which are fed by glaciers. In this study we have shown the effect of solar variability on regional climate by altering the river discharge and incursion of warm water pool into the region adjoining Bay of Bengal during seasonal dry period. The incremental growth bands present in the modern day Meretrix sp and Late Holocene Crassostrea sp. were examined for reconstruction of temperature and water composition at the head bay region of the river Ganges. The conventional C14 techniques on fossil oyster yielded age of 2765 ± 130 yr B·P., which coincides with a solar minima. Analysis of clumped isotope thermometry on the growth bands provided temperature estimates for the growth of shells. The temperature estimates for the modern shell, suggesting range of values showed a range between 13° and 42 °C, close to the observed temperatures recorded in the climatological data while the fossil shell had a range of values between 22° and 38 °C. The δ18O measured in the aragonite together with the estimated temperature were used to deduce the water composition during growth at equilibrium condition. The water δ18O varied between −4.8‰ and 1.2‰ for the modern sample, close to the observed values of water measured near this locality, while the range in water composition inferred for the paleo samples was from −2.37‰ to 0.82‰, suggesting a stronger influence of sea water throughout the year. The results are consistent with the argument of infiltration of water from neighbouring warm water pool into the estuary. A similar approach can be extended to evaluate the effects of climate variability due to differential action of river discharge into the sea at seasonal time scales based on available mollusc shells in the sedimentary successions from the region.

Reproducibility of Ba/Ca variations recorded by northeast Pacific bamboo corals

AbstractTrace elemental ratios preserved in the calcitic skeleton of bamboo corals have been shown to serve as archives of past ocean conditions. The concentration of dissolved barium (BaSW), a bioactive nutrientlike element, is linked to biogeochemical processes such as the cycling and export of nutrients. Recent work has calibrated bamboo coral Ba/Ca, a new BaSW proxy, using corals spanning the oxygen minimum zone beneath the California Current System. However, it was previously unclear whether Ba/Cacoral records were internally reproducible. Here we investigate the accuracy of using laser ablation inductively coupled plasma mass spectrometry for Ba/Cacoral analyses and test the internal reproducibility of Ba/Ca among replicate radial transects in the calcite of nine bamboo corals collected from the Gulf of Alaska (643–720 m) and the California margin (870–2054 m). Data from replicate Ba/Ca transects were aligned using visible growth bands to account for nonconcentric growth; smoothed data were reproducible within ~4% for eight corals (n = 3 radii/coral). This intracoral reproducibility further validates using bamboo coral Ba/Ca for BaSW reconstructions. Sections of the Ba/Ca records that were potentially influenced by noncarbonate bound Ba phases occurred in regions where elevated Mg/Ca or Pb/Ca and coincided with anomalous regions on photomicrographs. After removing these regions of the records, increased Ba/Cacoral variability was evident in corals between ~800 and 1500 m. These findings support additional proxy validation to understand BaSW variability on interannual timescales, which could lead to new insights into deep sea biogeochemistry over the past several centuries.

Are Pacific spiny dogfish lying about their age? A comparison of ageing structures for Squalus suckleyi

Historically, Pacific spiny dogfish (Squalus suckleyi) have been aged using dorsal fin spines, a method that was validated through bomb radiocarbon analysis and oxytetracycline tagging. However, ages generated using this method generally have poor precision and require estimation of missing growth bands in eroded spines, prompting a search for improved age determination methods. In the present study, spiny dogfish were aged using the historical spine method and a new method involving stained thin sections of vertebral centra. Results of an inter-laboratory exchange demonstrated the need for readers to calibrate ageing criteria with a reference collection before reading structures, a practice that yielded significant improvements in between-reader precision of spine band pair counts. After calibration, the primary readers examined the full sample set. The two structures yielded similar age estimates for younger animals, but centrum estimates were consistently younger than spine estimates after age-10. Although further work is necessary to fully explore potential reasons for the observed bias, such as centrum size and location within the vertebral column, at the present time centra are not a suitable alternative to dorsal fin spines for age determination of Pacific spiny dogfish >10 years of age.

Morphological restudy of the type species of Xibeiestheria (Spinicaudata) from the lower Aptian, northwestern China

The fossil clam shrimp genus Xibeiestheria Wang in Shen et al., 1982, a component of the well-known Early Cretaceous Yanjiestheria fauna, was originally described from the lower Aptian Jingchuan Formation of Yanchi County, Ningxia Hui Autonomous Region of northwestern China. The morphological re-examination under an SEM of the holotype of the type species Xibeiestheria pora Wang in Shen et al., 1982 has revealed new taxonomic features not previously recognized. These include: (1) growth lines with serrated lower margins, having a row of small pores; (2) widely spaced radial lirae intercalated cross bars on growth bands in the dorsal part of the carapace; (3) fine reticulum occurring within coarse reticulation on growth bands in the middle part of the carapace; (4) puncta radially aligned along the widely spaced radial lirae on growth bands in the lower part of the carapace.

Age and growth of the banded guitarfish Zapteryx exasperata (Chondrichthyes: Trygonorrhinidae)

The banded guitarfish (Zapteryx exasperata) is the third most abundant ray species in the artisanal elasmobranch fishery of Baja California Sur, Mexico. However, there is no biological information about its age and growth parameters, limiting the application of some quantitative population assessment methods, such as demographic models. The aim of the present study was to estimate, for the first time, age and individual growth of Z. exasperata. Biometric data from 244 individuals and 236 vertebrae were analysed. The largest number of banded guitarfish in fishery landings was observed during April and August, with a female:male sex ratio of 1:1.8. The size range was 56.4–103-cm total length (TL) for females and 51.6–92cm TL for males, with females being significantly larger than males (P<0.05). The periodicity of the vertebral edge suggests that growth band pairs form annually. The estimated age structure was 5–22.6 years for females and 4–19.6 years for males, with significant differences between sexes (P<0.01). The goodness-of-fit of three models was evaluated. For the von Bertalanffy growth model, the parameters were as follows. For females: theoretical maximum length, L∞ = 100.71cm TL; growth coefficient, k = 0.144year–1; and theoretical age at length zero, t0 = –0.39years. For males: L∞ = 89.78cm TL; k = 0.174year–1; and t0 = –0.65years.

Recent Advances In Understanding the Similarities and Differences of Colombian Euclases

Abstract Colombian euclase is rare and associated with emerald in medium-temperature hydrothermal veins hosted by Lower Cretaceous black shales (BS). The original sources of euclase production were the mining districts of Gachala and Chivor in the eastern emerald belt, but in 2016 euclases were also found at the La Marina mine in the western emerald belt. The present study is centered on a chemical and mineralogical examination of zoned Colombian euclase sold on the gem market as “trapiche”. Its texture is characterized by growth bands and sectors distinguished by the presence of numerous inclusions (mainly pyrite, carbonates, and organic matter) which represent around 0.2% of the total volume of the crystals. X-ray computed tomography showed that the largest inclusions are randomly located, whereas the small inclusions are concentrated in the center of the crystals, along the crystallographic b axis, between neighboring growth sectors and between growth bands in each sector. The texture cannot be defined as “trapiche”, like that of Colombian emeralds, because there is no matrix material from the surrounding BS trapped between the growth sectors and accumulated as dendrites. Three-phase fluid inclusions (FI) containing halite, liquid, and vapor phases are also observed in the euclase, and their volume is identical to that of the inclusions in emerald. Chromium and vanadium are the main chromophores, and the highest concentrations (1240 and 400 ppm, respectively) were found in deep blue-colored zones. Surprisingly, the euclase crystals have high Ge contents, between 230 and 530 ppm. The Rare Earth Element (REE) patterns of euclase are inherited from the enclosed BS or albitized and carbonatized BS. Euclase has the same REE pattern as emerald from the Gachala mines with an Eu anomaly (Eu/Eu* ∼ 0.40) and a depletion in Heavy Rare Earth Elements (HREE). The present study allows for the reconstruction of the formation conditions of “trapiche” euclase and discussion about its probable geographic origin, i.e ., the eastern emerald belt.

Identifying major events in two sturgeons' life using pectoral fin spine ring structure: exploring the use of a non-destructive method.

Maturation is one of the most important life history traits that influences on many ecological characteristics of animals. This study aimed to describe the indirect distinguish of first reproduction and habitat shift (transition from the pelagic to benthic environment), using the width of translucent and annuluses of the pectoral fin spine of two sturgeon species, Persian sturgeon, Acipenser persicus, and starry sturgeon, Acipenser stellatus. Interpretation of growth bands in pectoral fin sections was done objectively using direct reading of thin sections and image analysis. The results showed that changes in the profiles of translucent and annuluses occurred at the time of habitat shift and first reproduction. Females of both sturgeons move to the deeper waters earlier than males, which can be considered as strategy for the prolonged gonad development of female individuals. Estimated age at maturity for A. persicus (9years for female and 7years for male) was higher than A. stellatus (7years for female and 6years for male), which coincide with abrupt reduction in annuli width. Marks of habitat shift and first reproduction in the pectoral fin spine are species-specific characters and enable life history traits to be identified.

Clam shrimp genus Ordosestheria from the Lower Cretaceous Dalazi Formation in Jilin Province, north-eastern China

Ordosestheria Wang, 1984 was originally described from the lower Aptian Jingchuan Formation (previously the sixth member of the Zhidan Group) in north-western China. It was recovered from the lower Barremian Bouhedma Formation in southern Tunisia. However, we identified species of Ordosestheria from the upper Albian Dalazi Formation in north-eastern China, which were previously identified as orthestheriids. This means that the distribution area of Ordosestheria is wider than we thought before. Through the SEM examination of specimens of Or. multicostata (Chen in Zhang et al., 1976), new features have been discerned: 1) small-sized polygonal reticulation occurs on growth bands near the umbo; 2) reticulation changes into evenly distributed puncta; 3) then widely spaced radial lirae with intercalated fine puncta; 4) puncta are disappeared on middle and lower part of the carapace, leaving an undulating upper part and a row of small pits along the lower margin of each growth band; 5) growth lines are serrated in their lower margins. As a result, Ordosestheria is also a principal component of the Yanjiestheria clam shrimp fauna, and can be an index genus for the subdivision of non-marine sequences in China.

Mechanisms of fine extinction band development in vein quartz: new insights from correlative light and electron microscopy

Fine extinction bands (FEBs) (also known as deformation lamellae) visible with polarized light microscopy in quartz consist of a range of nanostructures, inferring different formation processes. Previous transmission electron microscopy studies have shown that most FEB nanostructures in naturally deformed quartz are elongated subgrains formed by recovery of dislocation slip bands. Here we show that three types of FEB nanostructure occur in naturally deformed vein quartz from the low-grade metamorphic High-Ardenne slate belt (Belgium). Prismatic oriented FEBs are defined by bands of dislocation walls. Dauphine twin boundaries present along the FEB boundaries probably formed after FEB formation. In an example of two sub-rhombohedral oriented FEBs, developed as two sets in one grain, the finer FEB set consists of elongated subgrains, similar to FEBs described in previous transmission electron microscopy studies. The second wider FEB set consists of bands with different dislocation density and fluid-inclusion content. The wider FEB set is interpreted as bands with different plastic strain associated with the primary growth banding of the vein quartz grain. The nanometre-scale fluid inclusions are interpreted to have formed from structurally bounded hydroxyl groups that moreover facilitated formation of the elongate subgrains. Larger fluid inclusions aligned along FEBs are explained by fluid-inclusion redistribution along dislocation cores. The prismatic FEB nanostructure and the relation between FEBs and growth bands have not been recognized before, although related structures have been reported in experimentally deformed quartz.

The growth and perfection of β-cyclotetramethylene-tetranitramine (HMX) studied by laboratory and synchrotron X-ray topography

An examination has been made of the defect structure of crystals of the energetic material β-cyclotetramethylene-tetranitramine (HMX) using both Laboratory (Lang method) and Synchrotron (Bragg Reflection and Laue method) techniques. The results of the three methods are compared with particular attention to the influence of potential radiation damage caused to the samples by the latter, more energetic, technique. The comparison shows that both techniques can be confidently used to evaluate the defect structures yielding closely similar results. The results show that, even under the relatively casual preparative methods used (slow evaporation of unstirred solutions at constant temperature), HMX crystals of high perfection can be produced. The crystals show well defined bulk defect structures characteristic of organic materials in general: growth dislocations, twins, growth sector boundaries, growth banding and solvent inclusions. The distribution of the defects in specific samples is correlated with the morphological variation of the grown crystals. The results show promise for the further evaluation and characterisation of the structure and properties of dislocations and other defects and their involvement in mechanical and energetic processes in this material.

Age determination in crustaceans: a review

Crustaceans, a commercially important class of arthropods in fisheries and aquaculture, represent a major worldwide food component for human consumption. Recently, growing interest regarding the ageing and longevity of crustaceans has led to advancement in the field of age determination methods, including the use of lipofuscin and growth band counts, veering from the classic approach of size modal analysis. This manuscript provides a comprehensive overview of literature published between 1990 and 2016 on popular age determination methods (length–frequency analysis, lipofuscin analysis, and growth band counts) applied to five main crustacean taxa (shrimp, krill, crayfish, crabs and lobsters). Of the 231 studies examined, 83% used length–frequency analysis, 13% used lipofuscin and 4% used growth bands. Validation, a necessary step to support results provided by age estimation studies, was included in 71% and 56% of the reviewed published papers that used lipofuscin and growth band counts, respectively. So far, growth band counts have been the only direct method of determining crustacean age. This method requires validation in all species before routine application in stock assessment and/or conservation purposes.

Skeletal growth controls on Mg/Ca and P/Ca ratios in tropical Eastern Pacific rhodoliths (coralline red algae)

The Mg/Ca ratios of non-geniculate coralline red algae (CA) are often assumed to be solely dependent on the sea surface temperature (SST) in which they grow, suggesting that they are ideal proxies for SST reconstruction. Mg/Ca ratio cyclicity is also commonly used as a marker for annual growth band identification in many CA species. However, other controls on elemental uptake such as light, calcification mechanisms, and vital effects may control elemental ratios (e.g. Mg/Ca and P/Ca) in certain genera or species of CA, thus complicating the use of Mg/Ca and P/Ca ratios as a proxy source for SST and paleo-environmental reconstructions. Here we present evidence showing that the Mg/Ca and P/Ca ratio cyclicity in unattached living tropical Lithothamnion sp. (n=8) rhodoliths correlate >90% to the number of sub-annual growth bands (n=1 to 20) formed during a 172-day controlled growth experiment and not to temperature or other environmental conditions (e.g. salinity, pH, etc.). This pattern is also observed in the wild, pre-experimental growth further supporting that the bands are not annual. The Mg/Caalga (R2=0.67; p-value=0.013; n=8) and P/Caalga (R2=0.64; p-value=0.018; n=8) significantly correlate to skeletal extension during the experiment. This work has implications for trace elemental proxy development using CA as well as the influence of skeletal extension on elemental incorporation in biogenic carbonates, particularly rhodoliths of Lithothamnion sp. from the Gulf of Panama, Panama.

Bomb radiocarbon analyses validate and inform age determination of longnose skate (Raja rhina) and big skate (Beringraja binoculata) in the north Pacific Ocean

Age and growth estimates based on growth band counts of sectioned vertebrae have been produced for longnose skate (Raja rhina) and big skate (Beringraja binoculata [formerly Raja binoculata]) populations in the Gulf of Alaska, British Columbia and California. Previous growth studies involving estimates from different laboratories in the USA (Alaska Fisheries Science Center, AFSC; Pacific Shark Research Center, PSRC at Moss Landing Marine Laboratories) and Canada (Fisheries and Oceans Canada, DFO) have produced dissimilar results for either species, highlighting the need for development of a consistent age determination protocol and more importantly an age validation study. Archived large specimens of longnose skate and big skate collected in Monterey Bay, CA, in 1980 and 1981 had minimum preliminary age estimates from vertebral growth band counts old enough to suggest that radiocarbon (14C) signals from bomb testing conducted in the late-1960s could be used to establish dates of growth band formation. To this end, we micro-milled skate vertebral thin sections, measured Δ14C using mass spectrometry, and estimated year of growth band formation based on the estimated age from growth band counts using both unstained and stained preparation methods Non-linear random effects modeling, implemented in a Markov Chain Monte Carlo (MCMC) simulation, was used to compare the skate Δ14C data set to a marine teleost otolith reference chronology for the California Current System. Results showed Δ14C measurements for big skate were non-informative as none of the archived samples were old enough for comparison to the reference curve, hence validation of the age estimation approach was not possible. However, for longnose skate, Δ14C data were more informative to fit pulse function models and compare results to the reference chronology. Modeling results indicated longnose skate age estimates based on unstained vertebral thin sections were less biased (overestimated to a smaller degree) than estimates based on stained vertebral thin sections. The degree of bias depended on agency ageing criteria, with the least biased age estimates produced by age readers from the AFSC. The AFSC age estimates had about a 70% probability that age estimates of longnose skate was within+/− 2 years of the expected age based on the radiocarbon assays. We were able to validate the age estimation methodology for longnose skate and establish criteria for growth band counts, which should now be useful to generate region-specific accurate growth and life history parameters required for more reliable stock assessment approaches.

SEM morphological study of the type species of Ordosestheria Wang, 1984 (Spinicaudata) from Ordos Basin of mid-west China

SEM morphological study of the type specimens of Ordosestheria wujiamiaoensis Wang, 1984 from the non-marine lower Aptian Jingchuan Formation in Inner Mongolia of the Ordos Basin in mid-west China has revealed taxonomic features not previously seen: 1) a row of small pits along the lower margin of each growth band in the lower part of the carapace; 2) growth lines are serrated in their lower margins; 3) a row of small pores on each growth line may indicate that through which a row of setae has developed. In consideration of the first occurrence of Ordosestheria from the lower Barremian of southern Tunisia, ordosestheriids may most likely have originated in North Africa and then dispersed to eastern Asia in early Aptian, and became a member of the well-known Jehol Biota.

Lagoon nurseries make a major contribution to adult populations of a highly prized coastal fish

AbstractThis study investigated the contributions of five putative nursery areas, namely four coastal lagoons and the marine coastal zone, to the local offshore fishery of the gilthead sea bream Sparus aurata, in the Gulf of Lion (NW Mediterranean). A detailed database of multi‐elemental lagoon and marine otolith signatures was developed, based upon analysis of multiple sequential spots across growth bands of the otoliths of juveniles (n = 142) sampled from the habitats over a 5‐yr interval. Adults of 10 annual cohorts (n = 114), fished throughout the Gulf, were then submitted to a similar microchemical analysis of the growth band of their otoliths that was formed after nursery settlement in their first year. Using the juvenile signature database and Random Forest classification algorithms, adults were re‐assigned to the lagoons or marine coastal zone as a nursery. More than 80% of adults derived from lagoons, being ≥ 85.0% for five consecutive cohorts. Therefore, the marine coastal zone apparently contributed few adults, especially as a function of surface area. The four lagoons differed, however, in their contribution to the S. aurata fishery. Two lagoons qualified as “Effective Juvenile Habitats” that contributed more than 20% of the adults fished. Two shallow brackish lagoons were “Nursery‐Role Habitats” that contributed almost twice as many adults, per unit surface area, as the overall average. Such information can support strategies for sustainable management of multiple coastal lagoon habitats, and of valuable fisheries that depend upon them.

Unusual ruby–sapphire transition in alluvial megacrysts, Cenozoic basaltic gem field, New England, New South Wales, Australia

Rare ruby crystals appear among prevailing sapphire crystals mined from placers within basaltic areas in the New England gem-field, New South Wales, Australia. New England ruby (NER) has distinctive trace element features compared to those from ruby elsewhere in Australia and indeed most ruby from across the world. The NER suite includes ruby (up to 3370ppm Cr), pink sapphire (up to 1520ppm Cr), white sapphire (up to 910ppm) and violet, mauve, purple, or bluish sapphire (up to 1410ppm Cr). Some crystals show outward growth banding in this respective colour sequence. All four colour zones are notably high in Ga (up to 310ppm) and Si (up to 1820ppm). High Ga and Ga/Mg values are unusual in ruby and its trace element plots (laser ablation-inductively coupled plasma—mass spectrometry) and suggests that magmatic–metasomatic inputs were involved in the NER suite genesis. In situ oxygen isotope analyses (secondary ion mass spectrometry) across the NER suite colour range showed little variation (n=22; δ18O=4.4±0.4, 2σ error), and are values typical for corundum associated with ultramafic/mafic rocks. The isolated NER xenocryst suite, corroded by basalt transport and with few internal inclusions, presents a challenge in deciphering its exact origin. Detailed consideration of its high Ga chemistry in relation to the known geology of the surrounding region was used to narrow down potential sources. These include Late Palaeozoic–Triassic fractionated I-type granitoid magmas or Mesozoic–Cenozoic felsic fractionates from basaltic magmas that interacted with early Palaeozoic Cr-bearing ophiolite bodies in the New England Orogen. Other potential sources may lie deeper within lower crust–mantle metamorphic assemblages, but need to match the anomalous high-Ga geochemistry of the New England ruby suite.

Study on Carapace Width Growth Band Counts Relationship of Orange Mud Crab, Scylla olivacea (Herbst, 1796) from Terengganu Coastal Waters, Malaysia.

Orange mud crab Scylla olivacea is one of the most important fisheries resources. A new development in ageing technique of crustaceans has been introduced. The detection of growth band deposited in hard structure of gastric mill in the cardiac stomach are found retained after moulting process can be used as age indicator and growth estimation. This study was carried out to determine the comparison between carapace width and growth band count of S. olivacea in Malaysia. Samples were collected from Setiu Wetlands, Terengganu, Malaysia from February until August, 2016. Samples were categorized based on their morphological measurements. The mesocardiac and zygocardiac ossicles in the gastric mill of S. olivacea was dissected out and preserved in solutions and underwent a cross sectioning process. A total of 76 of wild S. olivacea ranging from 6.56 to 12.84 cm in carapace width were analysed. The growth band counts were examined for each individual and ranging from 1 to 3 band counts. A positive linear relation was observed between CW and GBC with r2 = 0.5178, p<0.01. Overall, there was a strong, positive correlation between CW and GBC. Increase in CW were correlated with increases in GBC respectively for this species. Therefore, the carapace width, growth band counts and body weight can be used to improve data on growth, recruitment, maturation and mortality. Thus, this study would able to improve new ageing technique and contribute greatly to improve the conservation and management of S. olivacea in Setiu Wetlands, Terengganu, Malaysia.