Hyaline Zone Research Articles

Age and growth of the alfonsino Beryx splendens over the seamounts off New Caledonia

Age and growth of the alfonsino Beryx splendens from New Caledonia seamounts were determined by examination of whole and sectioned otoliths. One growth-ring (annulus) in the otoliths appears to be laid down each year. It consists of one opaque (summer, fast-growing) zone and one hyaline (winter, slowgrowing) zone. Thin-sections of otoliths revealed daily rings which allowed us to estimate that the formation of the nucleus takes ∼10 mo. The first annulus following the nucleus is incomplete. Females have a higher growth rate than males. Sexual maturity is reached at the age of 7 to 8 yr for males and 6 yr for females. Maximum age attained would be ∼20 yr for alfonsino >50 cm in fork length. the results are compared with those from the few other studies on the growth of alfonsino.

Microstructural growth in otoliths of conger eel (Conger myriaster) leptocephali during the metamorphic stage

Otolith growth during metamorphosis and some aspects of the early life history of conger eel (Conger myriaster) were determined as indicated from microstructure in otoliths of the leptocephali collected from Cheonsu Bay, Korea during May and June 1988. The leptocephali occurred from early May to late June in the study area. Larvae collected in early May were in the late leptocephalus stage, and the proportion of the metamorphosing leptocephali increased over time. Otoliths in the late leptocephalus stage showed a translucent zone only. Although the fish did not feed and the body length diminished during metamorphosis, the otolith continued to grow and, consequently, the opaque zone was formed outside the translucent zone. The inner translucent zone can be considered a leptocephalus zone, and the outer opaque zone a metamorphic zone. Assuming that the growth increments were deposited daily from hatching, the conger eel can be considered to have hatched between September and February. The number of increments in the inner hyaline zone ranged from 124 to 239, and was assumed to represent the number of days from hatching to the onset of metamorphosis. The duration of metamorphosis was estimated as 51 to 75 d based on the number of increments in the opaque zone at the end of the metamorphic stage.

The hyaline zone and associated root surface changes in experimental orthodontics in rats: a light and scanning electron microscope study.

Light and scanning electron microscopic (SEM) examinations were used to study the hyaline zone and associated root resorption after orthodontic treatment of the upper first molars of rats. The orthodontic treatment consisted of a fixed buccal expansion appliance with an initial force of 250 mN. The animals were divided into nine experimental groups with orthodontic treatment and one control group without orthodontic treatment. Three groups were sacrificed immediately after 1, 3, and 7 days of treatment, and six groups after 7 days of treatment followed by 1, 2, 3, 4, 5, and 6 weeks without treatment. A hyaline zone on the pressure side of the mesial root was identified at the light microscopic level of examination as well as the SEM examination as early as 1 day after the initiation of treatment. In the SEM it was found that on the roots of teeth studied in the first few days after initiation of treatment the hyaline tissue was so firmly attached to the root that it remained in place during the extraction and preparation procedures. After longer treatment periods these hyaline zones were lost at extraction or during the preparation for the SEM examination. The cementum surface under the hyaline zone had a smooth appearance suggesting that the surface had been modified by substances released from the hyaline zone. After 1 week of treatment, resorption in the cementum could be noticed. The resorption extended to the dentine as uncovered dentinal tubuli were found. Formation of reparative cementum started two weeks after treatment. Changes in the cementum surface as well as root resorption cavities could be seen for as long as 6 weeks after the cessation of orthodontic treatment.

Age and growth of South African dusky kobArgyrosomus japonicus(Sciaenidae) based on otoliths

The ages of dusky kob Argyrosomus japonicus, sampled from three regions along the South African eastern seaboard during 1991 and 1992, were determined from longitudinal sections of otoliths. The otoliths were selected from fish 35 – 1 750 mm total length. Ages from 0 to 42 years were recorded, but fish older than 27 were rare. Analysis of the otolith margins indicated that a single opaque and a single hyaline zone were being deposited annually. The first annulus was validated by analysis of daily increments. Observed lengths-at-age were highly variable. The filled generalized Von Bertalanffy growth equations were: L t = 1 473[1−e−0.22R(t+2.620)]2.468 for females, L t = 1 372[1−e−0.26M(t+2.620)]4.619 for males. Growth was faster in females, but in both sexes it slowed down after the age of 8. The relationships between otolith dimensions (length, height, mass and ostium to cauda distance) and fish length, in each of three regions, suggested that South African A. japonicus exist as three or more stocks.

Age Verification of Winter Flounder in Narragansett Bay

Abstract Between October 1987 and December 1988, 732 winter flounder Pleuronectes americanus, 91–380 mm total length, were collected during biweekly sampling from Narragansett Bay, Rhode Island. Left sagittal otoliths from these fish were embedded in epoxy resin, and transverse sections through the foci were prepared. With hyaline zones considered as annual increments, ages ranged from 1 to 11 for 608 winter flounder; 97% of the fish were younger than age 5. The dorsoventral otolith diameter was determined by linear regression analyses to be the best (r 2 = 0.90) of six “radial” axes for increment measurements. Marginal increment analyses for ages 1–4 showed that the increments, each composed of one opaque and one hyaline zone, are deposited annually, which clearly verified sectioned otolith ages for age-2 and age-3 fish. Opaque edges were prevalent in May, June, and July. Sectioned otoliths from winter flounder can provide clear increments and measurable increment widths through age 11. Two individuals r...

The Morphological Basis of Fish Age Estimation Methods Based on the Otolith of Nemadactylus macropterus

Relationships between the anatomy of the endolymphatic sac, sac otoconia, sagitta and astericus of Nemadactylus macropterus (Cheilodactylidae: Teleostei) are described and the variation in opaque and hyaline zones, sulcal checks, and daily microincrement widths along different growth axes of the otolith measured. The quantitative morphology of the otolith is used to compare the different age estimation techniques for N. macropterus that are based on opaque and hyaline zones, sulcal checks, and daily microincrements. Comparison of the different methods shows that at the present state of knowledge daily microincrements present the most credible age estimation method for N. macropterus.

Age determination of corvina reina (Cynoscion albus) in the Gulf of Nicoya, Costa Rica, based on examination and analysis of hyaline zones, morphology and microstructure of otoliths

Age determination of corvina reina (Cynoscion albus) in the Gulf of Nicoya, Costa Rica, based on examination and analysis of hyaline zones, morphology and microstructure of otoliths

Age determination of corvina reina (Cynoscion albus) in the Gulf of Nicoya, Costa Rica, based on examination and analysis of hyaline zones, morphology and microstructure of otoliths

This is the first age determination study for Cynoscion albus, a large tropical sciaenid, using otolith morphology and daily increment analysis. The practicality of both methods for age determination is illustrated by their consistent estimates of age and von Bertalanffy growth parameters. The daily increment analysis was used to validate the surface readings. An alternative, otolith morphometrics, is shown to hold promise for rapid prediction of fish age. Two multivariate linear regression models using gross otolith dimensions can estimate the age of C. albus to within 1 year. Growth parameter estimates are: from surface readings: L=127.5cm with K=0.12; from daily increment readings: L= 122.1 cm with K=0.17. Implications for the stock assessment of tropical fish using size instead of age are discussed.

Root resorption beneath the main hyalinized zone.

A previous investigation on the initial phase of root resorption associated with orthodontic overcompression of local areas of the periodontal ligament (PDL), indicated that a differentiation should be made between two stages: (1) the very first resorption occurring in the periphery of the main necrotic zone; and (2) the root resorption occurring on that part of the root surface situated beneath the main bulk of necrotic tissue (Brudvik and Rygh, 1993a). The aim of the present investigation was to study the latter stage. Attention was focused on: (1) the possible association between the presence of necrotic tissue and root resorption; and (2) the cells that invaded and removed the necrotic tissue, as well as the cells that started to remove/resorb the cementum. Mesial movement of the upper first molars (rats) and lower first molars (mice) was performed by a fixed orthodontic appliance. The results indicate an association between the root resorption, and the presence and active removal of the hyalinized tissue. Root resorption beneath the main hyalinized zone occurred in areas where invading cells were observed close to the root surface. The majority of the cells involved in removal of the necrotic tissue and resorption of the root surface were multi-nucleated and TRAP-positive. It is hypothesized that multi-nucleated TRAP-positive cells when reaching the subjacent contaminated and damaged root surface after having removed necrotic PM tissue, continued to remove the cementum surface.

Assessment of the Migration of Atlantic Cod (Gadus morhuaL.) between the Stocks off West and East Greenland in 1984-86 by Means of Otolith Typing

A method to identify individual cod (Gadus morhua) originating from either of the nursery areas off West or East Greenland is described. The method is based on a visual classification of individual annuli of the cod otoliths (sagitta) into three different types based on the formation of opaque and hyaline zones. The different hydrographic conditions off East and West Greenland probably affected the growth of the cod and were thus manifested as natural tags, in the form of different annuli of the otoliths. The calculation of emigration and immigration rates using the otoliths as natural tags confirmed the cod migration derived from tagging experiments, i.e. a one-way migration from West to East Greenland. In 1984–86, a very strong and rapid emigration of maturing cod from West to East Greenland occurred. The coefficients of emigration of the cod stock off West Greenland increased with age, pointing to a homing phenomenon as the migration factor.

The initial phase of orthodontic root resorption incident to local compression of the periodontal ligament.

The present light microscopic investigation was undertaken in order to study the initial phase of orthodontic root resorption in areas of pressure and, more specifically, to focus on the first cells that penetrate the root surface. Twenty-one upper first molars (rats) and 31 lower first molars (mice) were moved mesially by a fixed orthodontic appliance. The experimental periods were 1, 2, 3, 4, and 5 days in rats, and 1, 2, 3, 4, 5, 6, 7, and 8 days in mice. Tartrate-resistant acid phosphatase (TRAP) and Haematoxylin Eosin (H&E) stains were used. Root resorption related to a hyalinized zone showed a consistent pattern: Root resorption started in the circumference of the necrotic hyalinized tissue. In the central parts of the hyalinized zone frontal root resorption occurred 3-4 days later than in the periphery. Indications that the mechanisms for circumferential and central resorption differed was the reason for presenting only the periphery stage in this paper. The initial penetration of cells into precementum/cementum occurred at the peripheries or at a short distance from the peripheries of the hyalinized zone. These cells were TRAP-negative, indicating that they were not clasts or clast precursors. Before this happened TRAP-negative macrophage-like cells were observed at the borderline between the hyalinized tissue and vital periodontal membrane (PM). TRAP-positive cells were first observed in the bone marrow spaces. During the later stages mono- and multi-nucleated TRAP-positive cells were participating in active removal of the hyalinized tissue toward the root surface, and in resorption of cementum and dentine.

Effects of solar radiation on the population dynamics of juvenile flatfish in the shallows of the Wadden Sea

During the first days after their arrival in the Wadden Sea, newly settled plaice Pteuronectes platessa L., flounder, Platichthys flesus L., and sole, Solea solea L., stay at low tide in the residual waters on the tidal flats. Here they can be exposed to high levels of solar radiation and extreme temperature conditions. As a result of the extreme temperatures, all settlers eventually leave the shallows and start to exhibit tidally‐phased feeding migrations from the tidal channels on to the submerged fiats, In contrast to warm summers, for example 1982, no formation of a hyaline zone could be detected in the otoliths of surviving O‐group plaice in 1990, 4 weeks after such a mass emigration, which could be directly observed on particular days in both hot and cold summers. Analysis of UV‐B radiation data indicated that in 1990 cloud cover and wind conditions during the settling period protected the post‐larvae from high temperature and radiation stress which is necessary to induce hyaline zones in the otoliths. Nevertheless, histological examination of the dorsal skin revealed cellular changes characteristic of sunburn damage in part of‐the O‐group plaice population in 1990.Mortality of O‐group plaice during and after such a mass emigration, which was directly observed in the drainage gulleys in 1982, was estimated at approximately 14–27%. This rate is assumed to be close to the maximum mortality which can be expected from abiotic factors for O‐group plaice in the Wadden Sea.

Distribution, Growth and Food Habits of the Atlantic Wolffish (Anarhichus lupus) from the Gulf of Maine-Georges Bank Region

Distribution, Growth and Food Habits of the Atlantic Wolffish (<i>Anarhichus lupus</i>) from the Gulf of Maine-Georges Bank Region

Biology of the western minnow, Galaxias occidentalis Ogilby (Teleostei : Galaxiidae), in a south-western Australian river

The size and age composition, growth and diet of the western minnow, Galaxias occidentalis, in the southern branch of the Collie River in south-western Australia were determined from samples collected at approximately monthly intervals between January 1984 and December 1986. The prominent, narrow hyaline zone on otoliths was shown to be formed annually and thus valid for ageing these fish. An examination of the otoliths of 4711 fish indicated that 69.2 and 26.8% of the fish caught belonged to the 0 + and I + age classes, respectively. While the vast majority of the remaining fish represented the II + age class, a few III + and IV + and one V + fish were also recorded. Growth was seasonal, being greatest in spring and autumn and effectively ceasing in winter. Females began to grow faster than males during their first autumn of life. The respective mean lengths of males and females were ∼ 70 and 75 mm at the end of the first year and ∼ 90 and 100 mm at the end of the second year. The largest fish caught was a III + female measuring 163 mm and weighing 32.0 g. The respective von Bertalanffy growth curve parameters for L∞, K and t0 were 109, 0.758 and - 0.338 for males, and 124, 0.762 and - 0.223 for females. Although the diet of G. occidentalis was always dominated by small terrestrial fauna, and particularly insects, conspicuous seasonal differences were found between the more important of the other components. Data on body size, growth and diet of G. occidentalis are compared with those recorded for other galaxiids.

Otoliths of deep water fishes: structure, chemistry and chemically-coded life histories

1. 1. The gross anatomy and crystalline ultrastructure of the external surfaces has been described for the sagittal otoliths of a 6 million year old fossil otolith and the following bottom-living deep-water teleosts (families in parenthesis): Coryphaenoides (Nematonurus) armatus (Macrouridae), Coryphaenoides (Chalinura) mediterraneus (Macrouridae), Celonurus globiceps (Macrouridae), Coryphaenoids (Chalinura) leptolepis (Macrouridae), Antimora rostrata (Moridae), Halosaurus pectoralis (Halosauridae), Psychrolutes obesus and Neophrynichthys angustus (Psychroultidae). 2. 2. Sections of otoliths were scanned by proton microprobe to yield three dimensional maps of the elemental density of calcium, strontium and, in some otoliths, zinc. The same sections were examined optically for opaque and hyaline zones. For some otoliths, broken sections were examined by SEM and their internal crystalline structure described. 3. 3. The theoretical basis for using cycles in elemental (particularly strontium) composition to interpret life history is examined. Life history information from elemental composition is compared with other information derived both from otoliths and field observations of the species involved.

筑後川におけるニゴイの年齢と成長

Age and growth of the cyprinid fish Hemibarbus barbus in the Chikugo River were studied by interopercle reading of 316 specimens. Interopercle radii and ring radii were measured from the focus to the anterior edge and to outer margins of the hyaline zones, respectively. The relationship between interopercle radius and standard length was shown as a straight line. The outer margins of the hyaline zones as annual rings were formed once a year in April. Growth of this fish was expressed by the von Bertalanffy's equation as Lt= 519.7 [1-exp{-0.195(t+0.158)}] for males and Lt=571.3 [1-exp{-0.167(t+0.289)}] for females (Lt: standard length in mm, t: age). Most of 1- to 3-year-old immature fish were found in the fresh water of the tidal reaches all the year round. The spawning run of this fish mostly comprised of 4- and 5-year-old groups from the tidal reaches to the reaches about 20km upstream occurred in April. Therefore it seems that the migration of H. barbus in the Chikugo River may be classified as potamodromous migration or fluvial migration.

On the life history of Cape horse mackerelTrachurus trachurus capensisoff the south-east coast of South Africa

Cape horse mackerel on the south-east coast of South Africa attain a maximum age of 10 years. One opaque and one hyaline zone are deposited on the otoliths per year and growth is described by the equation Lt = 503 (1 − e−0,427(t + 0,194)) mm. Fifty-per-cent sexual maturity is attained in the second year, between 320 and 330 mm total length (TL). Horse mackerel first recruit to the fishery in their second year, although 50-per-cent recruitment only occurs at 440 mm TL, at five years of age. Throughout each year the size distribution of the catch is unimodal, between 440 and 499 mm TL, the age of the fish ranging from five to nine years. The reproductive season extends from June to November during which there are two spawning peaks, and immediately after spawning the gonads undergo a heavy nematode infestation. Sexes are evenly distributed at a ratio of 1 : 1. Along the South-East Coast the species filter-feeds non-specifically on zooplankton. The findings of this study support the hypotheses that adult Cape horse mackerel undertake a spawning migration and that the fish on South Africa's south-east and west coasts and those off southern Namibia are a single stock.

Growth and age structure of alfonsino(Beryx splendens)from the lower east coast, North Island, New Zealand

Abstract Commercial landings of alfonsino (Beryx splendens Lowe, 1834) from the Palliser Bank, Tuaheni High, and Paoanui Ridge were sampled to describe growth and determine the age composition of catches. The study indicated that one opaque and one hyaline zone were formed annually in sagittal otoliths, the hyaline zone being deposited in late autumn. Fish were probably about 10 months old when the otolith nucleus was fully formed. The length‐weight equations for males and females differed and both changed throughout the year in parallel with the spawning cycle. Size‐selective mortality did not occur on the Palliser Bank. Females were significantly larger at any given age than males on all grounds examined, but growth of males and females appeared consistent between grounds. Growth was slower than in Japanese waters and the Atlantic. Age structure varied between grounds, but was reasonably constant over time on the Palliser Bank. Full recruitment to the commercial fishery occurred at age 5 on the Palliser...

Age and growth of Lutjanus kasmira (Forskål) in Hawaiian waters

The growth of Hawaiian taape, Lutjanus kasmira, was studied by examining otoliths and by analysing length‐frequency distribution. Annual hyaline and opaque markings were visible in whole mounts of sagittae, which were verified by enumeration of daily increments with a scanning electron microscope (SEM) and through marginal increment analysis. The von Bertalanffy growth curve was fitted to the data, resulting in: image where t.l. is total length (cm) and t is age (years). SEM observations revealed that the slowgrowth hyaline zones were composed of daily increments too small (0.4–0.8 μm) to be resolved optically. Thus, age estimates derived by numerically integrating otolith growth rate data obtained with a light microscope showed a negative bias, resulting in overestimation of growth rates. Parameter estimates obtained from three different types of length‐frequency analysis were also unstable. This was due, at least in part, to differences in the size composition of fish sampled with different fishing gears and from different depths.The growth rate registered in Hawaii falls within the reported growth coefficients of lutjanids, whereas it is one of the highest in the Pacific and clearly higher than a deep‐water lutjanid species growth in Hawaii. Probably, this high growth rate may have been enhanced by the relative lack of competitors in the depauperate Hawaiian marine fish community.

Changes in the stock composition and abundance of spawning Gemfish Rexea solandri (Cuvier), Genpylidae, in South-eastern Australian waters

Data collected during a study of the New South Wales trawl fishery showed a marked increase in landings of gemfish Rexea solandri (Gempylidae) during the late 1970s, which was due to the exploitation of winter spawning aggregations. Catches peaked at 5100 t in 1980, but declined to about 3000 t over the following few years, rising again to around 4000 t in 1987. Daily landings data for individual vessels were analysed for the period 1973-86. Fishing effort (target days) was standardized by comparison of each vessel's catch per target day with that of an arbitrary standard vessel. Catch per standard day declined by about 70% between 1980 and 1983. The mean caudal fork length of gemfish from spawning run catches declined from 79 cm to 71 cm over the period 1975-85, reflecting a reduction in the number of large fish in the catch and the recruitment of smaller fish into the spawning aggregations. Ages of gemfish were estimated from counts of hyaline zones on the sagittal otoliths. For age classes 1 to 3, otolith-determined ages were validated by means of modal analysis of monthly length-frequency data, but no validation was possible for the older age classes. Males sampled from spawning-run catches were estimated to be predominantly 4-8 years of age, with a maximum age of 11, whereas females were estimated to be predominantly 5-10 years old, reaching a maximum age of 16. For each sex, the proportion of older fish in the catch declined between 1980 and 1986, and there was a corresponding increase in the prominence of newly recruited age classes. It was concluded that there had been a substantial decline in the relative abundance of spawning gemfish, and that significant changes had also occurred in the size and age composition of the stock, consistent with the effects expected to result from exploitation.