Annulus Formation Research Articles

Survival of European Mouflon (Artiodactyla: Bovidae) in Hawai'i Based on Tooth Cementum Lines

Reliable techniques for estimating age of ungulates are necessary to determine population parameters such as age structure and survival. Techniques that rely on dentition, horn, and facial patterns have limited utility for European mouflon sheep (Ovis gmelini musimon), but tooth cementum lines may offer a useful alternative. Cementum lines may not be reliable outside temperate regions, however, because lack of seasonality in diet may affect annulus formation. We evaluated the utility of tooth cementum lines for estimating age of mouflon in Hawai'i in comparison to dentition. Cementum lines were present in mouflon from Mauna Loa, island of Hawai'i, but were less distinct than in North American sheep. The two age-estimation methods provided similar estimates for individuals aged ≤3 yr by dentition (the maximum age estimable by dentition), with exact matches in 51% (18/35) of individuals, and an average difference of 0.8 yr (range 0–4). Estimates of age from cementum lines were higher than those from dentition in 40% (14/35) and lower in 9% (3/35) of individuals. Discrepancies in age estimates between techniques and between paired tooth samples estimated by cementum lines were related to certainty categories assigned by the clarity of cementum lines, reinforcing the importance of collecting a sufficient number of samples to compensate for samples of lower quality, which in our experience, comprised approximately 22% of teeth. Cementum lines appear to provide relatively accurate age estimates for mouflon in Hawai'i, allow estimating age beyond 3 yr, and they offer more precise estimates than tooth eruption patterns. After constructing an age distribution, we estimated annual survival with a log-linear model to be 0.596 (95% CI 0.554–0.642) for this heavily controlled population.

Partial aortic annulus avulsion and formation of aortic-left ventricle tunnel through interventricular septum after blunt cardiac trauma

Traumatic aortic-left ventricle tunnel through interventricular septum was particularly a rare event that has never previously been described. A 58-year-old male, with a history of blunt thoracic trauma caused by falling from height, was admitted to our institute for effort dyspnea. Chest computed tomography scan showed subaortic interventricular septal lumen communicating with coronary sinus and left ventricular outflow tract (LVOT). Transthoracic echocardiography revealed a shuttle flow from coronary sinus to LVOT bypassing aortic annulus during diastole. Operation examination found partial aortic annulus avulsion outside right coronary cusp involving superior interventricular septum dissection forming a tunnel breakthrough into left ventricular outflow tract. Both aortic orifice and LVOT orifice of the tunnel were closed with running Prolene suture and right coronary cusp annulus was fastened to aortic root with intermittent mattress suture. The postoperative course was uneventful. Echocardiography confirmed complete closure of the tunnel with residual trivial to mild aortic regurgitation during 1-month follow-up.

Validating annulus formation and examining the potential use of pectoral spines for age determination in Aristotle’s catfish (Silurus aristotelis)

Summary The potential use of pectoral fin spines for ageing purposes was examined in Aristotle’s catfish (Silurus aristotelis) and validated for growth proportionality and growth mark periodicity. Monthly samples (n = 436, total length range: 11.10–36.70 cm) were collected in Lake Pamvotis, Greece from November 2002 to December 2003. Marginal increment analysis showed that the spine width (SW) radius grew proportionally to total body length (TL) (TL = 9.581 + 6.83SW, r2 = 0.66, n = 431, P 0.80 in all cases) when removed from one side of the fish or the other. The procedure was based on individuals no older than 5 years of age; extrapolation to higher age classes may be critical.

Estimation of Period of Annulus Formation of Nibbler at the Coastal Waters of Izu Peninsula

Estimation of Period of Annulus Formation of Nibbler at the Coastal Waters of Izu Peninsula

Validation of scales and otoliths for estimating age of redband trout in high desert streams of Idaho

Studies validating aging structures for rainbow trout are sparse and none have been conducted for redband trout, a common western U.S. sub-species. Oxytetracycline mark-recapture methods (MR), marginal incremental analysis (MIA), and comparisons across multiple populations were used to evaluate the utility of two structures for aging redband trout in high desert streams. We assessed periodicity of annulus formation on scale and otolith samples from all age classes of trout residing in two streams, identified the location of the first annulus on otoliths, and compared age estimates and between-reader coefficient of variation on nine additional streams. The use of MIA successfully validated opaque zone periodicity for fish transitioning from age-0 to age-1, and from age 1 to age 2 in two streams. For fish at liberty 13 and 28 months in the same two streams, MR-derived age estimates from whole and sectioned otoliths were 94–100% accurate for fish from 2–9 years old. Scales were only 77% and 38% accurate for fish at liberty 13 and 28 months, respectively. Between-reader coefficient of variation (CV) for scales was high (11.5%), while CV for sectioned otoliths using whole otoliths as corroboratory structures averaged 2.3%. Scales were thus, an unacceptable aging structure for desert redband trout. Given the confusion in the literature, we suggest that more rigorous research should be conducted to define and explain otolith zone formation.

Validation of first annulus formation in red snapper otoliths with the use of an alizarin complexone fluorescent marker

The red snapper (Lutjanus campechanus) is among the most studied reef fish species in the Gulf of Mexico. Several studies have used counts of annuli in sectioned sagittal otoliths to age red snapper. However, interpretation of the putative first annulus has been a major source of debate among otolith readers throughout the Gulf of Mexico. Our objective was to use the chemical marker alizarin complexone to validate the periodicity of first opaque annulus formation in red snapper otolith sections. Juvenile red snapper were immersed in 100 mg alizarin complexone per L seawater solution in November 2005 and then reared in 6000 l circular tanks until July 2006. Otoliths were then removed from the fish and thin sectioned. All experimental otolith sections displayed a distinct fluorescent mark ranging from 0.62 to 0.96 mm from the core when viewed under the microscope with a rhodamine filter. The diffuse opaque annulus was located distally to the alizarin mark in all specimens (ranging from 0.88 to 1.51 mm). The distal position of the presumptive first annulus relative to the alizarin mark in all specimens indicates that this diffuse opaque annulus in red snapper sectioned otoliths forms during the first winter after hatching. Translucent marginal edges of all otolith sections indicate that first opaque annulus formation is completed by mid-July.

MGS TES observations of the water vapor above the seasonal and perennial ice caps during northern spring and summer

We report on new retrievals of water vapor column abundances from the Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) data. The new retrievals are from the TES nadir data taken above the ‘cold’ surface areas in the North polar region ( T surf < 220 K, including seasonal frost and permanent ice cap) during spring and summer seasons, where retrievals were not performed initially. Retrievals are possible (with some modifications to the original algorithm) over cold surfaces overlaid by sufficiently warm atmosphere. The retrieved water vapor column abundances are compared to the column abundances observed by other spacecrafts in the Northern polar region during spring and summer and good agreement is found. We detect an annulus of water vapor growing above the edge of the retreating seasonal cap during spring. The formation of the vapor annulus is consistent with the previously proposed mechanism for water cycling in the polar region, according to which vapor released by frost sublimation during spring re-condenses on the retreating seasonal CO 2 cap. The source of the vapor in the vapor annulus, according to this model, is the water frost on the surface of the CO 2 at the retreating edge of the cap and the frost on the ground that is exposed by the retreating cap. Small contribution from regolith sources is possible too, but cannot be quantified based on the TES vapor data alone. Water vapor annulus exhibits interannual variability, which we attribute to variations in the atmospheric temperature. We propose that during spring and summer the water ice sublimation is retarded by high relative humidity of the local atmosphere, and that higher atmospheric temperatures lead to higher vapor column abundances by increasing the water holding capacity of the atmosphere. Since the atmospheric temperatures are strongly influenced by the atmospheric dust content, local dust storms may be controlling the release of vapor into the polar atmosphere. Water vapor abundances above the residual polar cap also exhibit noticeable interannual variability. In some years abundances above the cap are lower than the abundances outside of the cap, consistent with previous observations, while in the other years the abundances above the cap are higher or similar to abundances outside of the cap. We speculate that the differences may be due to weaker off-cap transport in the latter case, keeping more vapor closer to the source at the surface of the residual cap. Despite the large observed variability in water vapor column abundances in the Northern polar region during spring and summer, the latitudinal distribution of the vapor mass in the atmosphere is very similar during the summer season. If the variability in vapor abundances is caused by the variability of vapor sources across the residual cap then this would mean that they annually contribute relatively little vapor mass to significantly affect the vapor mass budget. Alternatively this may suggest that the vapor variability is caused by the variability of the polar atmospheric circulation. The new water vapor retrievals should be useful in tuning the Global Circulation Models of the martian water cycle.

Age and growth of the European catfish (Silurus glanis) in a Turkish Reservoir and comparison with introduced populations

The European catfish, Silurus glanis, is native to eastern Europe and western Asia and is among the largest freshwater fish in the world. Despite its increasing economic importance and its frequent introductions, the ecology and life-history of this species is poorly known due to the difficulty of sampling such a large species in large rivers and standing waters. Our study provides the first data on age and growth of this species in Turkish waters, where it is native. We report the length-weight relationships and age and size structure of this population, which were significantly different between females and males. A marginal increment analysis indicated that annulus formation occurred between May and June. The estimates of three growth functions (von Bertalanffy, logistic and Gompertz) are reported, with the von Bertalanffy growth providing a better fit and more realistic parameter estimates. Growth rates were significantly higher in males than in females and were overall higher compared to other native populations but similar to introduced populations of similar latitude.

Age and growth of Distichodus antonii (Schilthuis, 1891) (Pisces, Teleostei, Distichontidae) in Pool Malebo, Congo River

The estimation of demographic parameters of Distichodus antonii, in Pool Malebo (Congo River), was obtained from analysis of 36 good scales samples. L‡ was estimated at 107.91 cm, K at 0.10 .year-1 and t0 at -0.67 year-1. The growth parameters calculated from this method revealed that this fish has a slow growth rate and it reaches a large size. The analysis of marginal increase shows that the formation of annulus takes place to the dry season. During the dry season, the environmental conditions are disturbed and the access to food becomes difficult. This is probably the base of the stress that induces the formation of annuli on the scales.

Age and Growth of Acrossocheilus fasciatus (Barbinae, Cyprinidae) from the Puxi Stream in the Huangshan Mountain, China

ABSTRACT Age and growth of Acrossocheilus fasciatus were determined using 592 specimens collected from the Puxi Stream in the Huangshan Mountain, China. Females and males both comprised four age groups. Annulus formation occurred during March and April for the first figs but during August and September for the second and third rings. Both sexes were significantly different in length-weight relationship but not significantly different in length-scale radius relationship. Total lengths back-calculated significantly increased with age for both sexes, but no significant difference was observed in the back-calculated length at every age between the two sexes, which perhaps suggests size homomorphism for this species. Inflection point was not observed in the growth curves of von Bertalanffy growth functions in total length, but it was observed in total weight for females at age 6.8 years and males at 5.2 years.

Age and growth analysis of the central mudminnow,Umbra limi(Kirtland, 1840)

Summary A rudimentary understanding of age, growth, and life-span is lacking for many non-game fishes. Growth characteristics of the central mudminnow (Umbra limi) have not yet been accurately described using reliable hard part analysis. The utility of scales and otoliths as ageing structures and quantified growth was examined in one lake and one stream population of central mudminnow. Scales were found to be of no utility in determining age due to inconsistent formation of yearly annuli and a high incidence of regenerated scales, while otoliths were easily extracted and considered to be an accurate ageing structure. Ages determined from scales were low compared to those from otoliths, and the difference in age interpreted from the two structures increased with fish age. A power function was fitted to describe the length-weight relationship for this species (a = 0.0069, b = 3.175). Von Bertalanffy growth parameters were estimated and compared for each population (Lake: L∞ = 114.20 mm, K = 0.30, t0 = −0.93; Stream: L∞ = 77.59 mm, K = 0.63, t0 = −0.76). The lake population showed greater size at age compared to the stream population, especially at older ages, and achieved a larger maximum size. Growth rate was also greater in the lake population (Lake: 1.74; Stream: 1.09 g year−1). Females were larger at age than males in both populations, however all individuals greater than age 3 were males. This work represents the first successful account of central mudminnow growth using hard part analysis.

The Outflow Tract in Transposition of the Great Arteries: An Anatomic and Morphologic Study

Neoaortic root dilatation is observed after the arterial switch operation for transposition of the great arteries. Although structural differences in the vessel wall of these patients may be of influence, we hypothesize that a histomorphologic difference in composition and embedding of the fibrous annulus in transposition of the great arteries may play a role in neoaortic root dilatation. Two normal human hearts and two unoperated human hearts with transposition of the great arteries, 1 day postnatal, were studied. Histologic sections stained for collagen, myocardium, and elastin were prepared, and three-dimensional reconstructions of the outflow tracts were made to enable comparison of the morphologic structures between the normal hearts and those with transposition of the great arteries. The amount of collagen in the arterial roots was diminished in hearts with transposition of the great arteries compared with the normal hearts. In addition, the anchorage and embedding of both arterial roots in the myocardium was less extensive in transposition of the great arteries. The changed position of the arteries in the malformed hearts results in less support for the roots from the surrounding atrioventricular myocardium. The combination of the observed histomorphologic differences in amount of collagen and myocardial support may be an explanation for the neoaortic root dilatation observed after the arterial switch operation. The developmental background of the observed deficient fibrous annulus formation may originate from an epicardial problem.

Non-lethal age determination for juvenile goliath grouper Epinephelus itajara from southwest Florida

Previous studies have developed size-at-age curves for goliath grouper; however, these data were based on relatively few immature individuals, and age estimation was otolith-based, requiring sacrifice of this federally protected fish. In the present study, scales, dorsal fin-rays and dor- sal spines were explored as potential non-lethal ageing alternatives for juvenile goliath grouper. Annulus marks were validated using marked-recaptured fish, oxytetracycline injections, and edge analysis. A subset of fish was sacrificed to compare the scale, spine and ray ages to otolith ages. A 40% recapture rate provided a useful time series of in situ age and growth data. Scale and ray ages were unreliable, but dorsal spines demonstrated agreement with corresponding otolith ages. Annuli were best represented by translucent bands in spines, as opposed to opaque bands in otoliths. Spines were positively validated for periodicity of annulus formation. Annuli formed at different times of the year in spines than in otoliths. By correcting for this difference using a biological age method, better agreement between otolith and spine age was achieved. Dorsal spines are recommended as the pri- mary method for ageing goliath grouper between the ages of 0 and 6 yr. This study illustrates the use of a non-lethal method to determine age of a protected species.

Using otolith morphometrics to quickly and inexpensively predict age in the gray angelfish ( Pomacanthus arcuatus)

We examined sagittal otoliths from 398 gray angelfish ( Pomacanthus arcuatus) collected from the lower Florida Keys between September 2000 and September 2003. Fish ranged in size from 78 to 442 mm total length (TL). Males had a mean TL of 329 mm ( n = 192), females had a mean TL of 308 mm ( n = 166), and an additional 56 fish were unsexed (mean TL = 239 mm). Sectioned otoliths displayed clear increments that were used to estimate fish ages. Marginal increment analysis validated the formation of a single annulus per year. The relationship between TL and age was described by the von Bertalanffy growth equation L t = 325.1[1 − exp(−0.0601( t + 0.828))] for females and L t = 388.5[1 − exp(−0.383( t + 0.923))] for males. Females and males grew rapidly for the first 5 years of life and eventually reached asymptotic lengths of ∼325 and ∼388 mm, respectively, with a maximum estimated age of 24 years. Morphometric parameters evaluated for use in the age model for gray angelfish included fish length and weight and otolith length, width, thickness, and weight. As with fish length, otolith length and width became asymptotic between the ages of 4 and 7. Otolith weight increased throughout the life of the fish, but the rate of increase slowed with age. Only otolith thickness was linear with fish age. Stepwise forward regression resulted in the following equation: ln (age + 1) = 1.157 + 2.542 × ln(otolith thickness) indicating that otolith thickness, which explained 89% of the variation, was the best predictor of age. Additional variables did not improve the regression, nor did dividing the data into subsets based on growth rate. Once the otolith thickness–age relationship was established, the simple process of measuring otolith thickness was as effective for determining the age of gray angelfish as the far more difficult process of sectioning and reading the otoliths. Use of similar models in ageing other species, along with periodic validation to ensure that the otolith parameter–age relationship has not changed over time, could simplify age data collection for population models. This, in turn, could potentially allow fisheries to be better managed at a significantly reduced cost.

Comparison of pelvic fin rays, scales and otoliths for estimating age and growth of bull trout, Salvelinus confluentus

Abstract The suitability of three anatomical structures to determine age and growth of bull trout, Salvelinus confluentus (Suckley), was assessed. Scales and pelvic fin rays collected from recaptured bull trout 96–265 mm TL were used to validate annulus formation and assess the accuracy and precision of back calculation. Ageing precision and agreement of assigned ages were compared among scales, fin rays and otoliths from bull trout 52–711 mm TL. Annulus formation was validated for 88% (14 of 16 fish) of recaptured bull trout using pelvic fin rays and 68% using scales (15 of 22 fish). Annulus formation in fin rays occurred between late April to early June, and the hyaline (non‐growth) band began forming in late August. Back‐calculated length was not significantly different from measured length at initial capture either for fin rays or scales (P ≥ 0.19), and absolute percent error was 7.2 ± 1.2 (mean ± SE; n = 14) for fin rays and 8.7 ± 1.9 (n = 15) for scales. Consistency of back‐calculated lengths at age between tag and recapture samples for individual fish was similar for fin rays (mean absolute difference = 8.2% ± 0.9; n = 33) and scales (9.4% ± 1.4; n = 40). However, fin rays (87% precision) and otoliths (90%) provided notably higher ageing precision than scales (68%) and closer agreement of assigned ages, particularly for fish older than age 4. Pelvic fin rays appear to offer more accurate and precise age and growth determinations than scales and a non‐lethal alternative to otoliths, but further work is needed to validate the accuracy and precision of ageing large, migratory bull trout.

Absence of annulus in human asthenozoospermia: Case Report†

The annulus is a septin-based ring structure located at the junction of the midpiece (MP) and the principal piece (PP) of spermatozoa flagellum. In the mouse, deletion of Septin 4, a structural component of the sperm annulus, prevents annulus formation and leads to MP-PP disjunction, flagellar bending, asthenozoospermia and male sterility. Testis anion transporter 1 (Tat1) is a germ cell-specific member of the SLC26 anion transporter family and is co-expressed with Septin 4 at the sperm annulus. Interestingly, Tat1 null sperm bear an atrophic annulus, causing a phenotype similar to that of Sept4 null sperm. We searched for Tat1 misexpression and/or mislocalization in spermatozoa from asthenozoospermic subjects (n = 75) and controls by performing an immunofluorescence detection assay on sperm smear preparations. We found one patient showing moderate asthenozoospermia, with 97% of sperm lacking Tat1, Septin 4 and Septin 7 proteins at the annulus. We confirmed the absence of the annulus structure by transmission electron microscopy and observed that spermatozoa from the patient displayed MP-PP disjunction and abnormal mitochondrial organization. We show that the structural defects in sperm are not caused by abnormal transcription or point mutations of the TAT1 and SEPT4 genes; however, although both proteins are expressed, they are not properly localized at sperm annulus. The case we studied, so far unreported in human, confirms the involvement of Tat1 and Septin proteins in the constitution of the annulus, but also raises questions about the function of this structure in human sperm motility.

Seasonal growth and life history of the catfishCalophysus macropterus(Lichtenstein, 1819) (Siluriformes: Pimelodidae) from the Amazon floodplain

Summary The objective was to study seasonal aspects of the piracatinga catfish (Calophysus macropterus) growth and its relationship with the flood pulse. Analyzed from June 1997 to May 1998 were 446 specimens from the Amazon River. Using the period regression model with several biometric indexes gave the following results: two periods of low growth were identified in the vertebrae of C. macropterus, the first during falling water (August) and the second during rising water (January), using marginal increment analysis (MIA). This pattern was also observed in the annual variation of the regression coefficient of the length–weight relationship (b), and Feeding Index (FI), but an inverse relationship was observed with the Maturity Index (MI). These results suggest that reproduction occurs from January to February in the rising water season, when C. macropterus reaches sexual maturity at 1.4 and 1.5 of age for females and males, respectively. The parameters of Bertalanffy’s model were SL = 40.05[1−e−0.44(t−0.37)] for females and SL = 41.9[1−e−0.42(t−0.36)] for males. Natural mortality was high (♀:0.42–♂:0.40) and longevity low (♀:6.8–♂:7.1 years). The present study demonstrates that seasonal growth in C. macropterus is correlated with the flood pulse, especially in periods of rising and falling waters. These results, analyzed by the periodic regression model, showed that reproduction, migration or changes in feeding behavior have relationships with annulus formation in hard structures in this species. All quantitative indexes show clear seasonal variation to be correlated with river water level fluctuations.

Age validation, growth and annual reproductive cycle of chub mackerelScomber japonicusoff the waters of northern Kyushu and in the East China Sea

The age and growth of chub mackerel Scomber japonicus collected from the East China Sea and the northern waters off Kyushu between June 2000 and June 2001 were determined by observing the otolith surface after dipping it in xylene. The translucent and opaque zones on the otolith surface were identified, and the number of translucent zones was counted. Monthly changes in the frequency of fish with translucent zones on the otolith margin, and in the marginal increments, indicated that the translucent zones were formed between April and June. The seasonal pattern of annulus formation on the otolith became clear by observing the otoliths of fish with known ages, and the otolith formation in wild fish was consistent with that of fish with known ages. The mean gonadosomatic index of male and female fish was high from March to May, and spawning females were observed from mid-March to mid-May. The estimated ages were 1–5 years for males and 1–6 years for females. The von Bertalanffy growth parameters did not significantly differ between male and female. The model was obtained as FLt=406×{1−exp[−0.372×(t+1.68)]

Validation of annulus formation in otoliths of a temperate population of adult African sharptooth catfish Clarias gariepinus using fluorochrome marking of wild fish

The deposition rate of growth zones in sagittal otoliths of wild Clarias gariepinus that were fluorochrome marked with oxytetracycline and recaptured after a period of between 0·44 and 2·13 years was consistent with the deposition of one growth increment annually.

Age-validation and growth of bluefish ( Pomatomus saltatrix) along the East Coast of the United States

We examine the age and growth of bluefish, Pomatomus saltatrix, along the U.S. east coast collected from Florida to New York during 2001–2003 ( n = 2652). We describe a new preparation technique for the otoliths that increases readability, and provide criteria for the interpretation of otolith microstructure. Annulus formation in otoliths for bluefish is validated for fish aged 1–8 using marginal increment analysis. This extends validation by 4 years to include the preponderance of age classes in the catch. A side-by-side comparison of ageing precision and bias was performed between otoliths and scales. When compared, precision was highest with sectioned otoliths, exceeding 87% across all years, and exceeding 99% within 1 year, up to age 13. In contrast, scales tended to over-age ages 1 through 5, and under-aged age 7 and older compared to sectioned otoliths. We used these otolith-based ages to evaluate age distribution in gears used in the fishery and to evaluate size-at-age data and to estimate growth parameters from the catch. No significant differences in the von Bertalanffy growth parameters were found in comparison by sex, year and between the South Atlantic and Middle Atlantic Bights using Kimura's likelihood-ratio test. The estimated von Bertalanffy model growth parameters for bluefish along the coast were L inf = 815.3 mm ±15.3, k = 0.311 ± 0.03, t 0 = −0.301 ± 0.18. These findings are then used to examine the implications for management of this ecologically and economically important coastal pelagic species.