Prevalence Of Atresia Research Articles

Hermaphroditism and the impact of environmental variables on atresia prevalence in the pen shell Pinna rugosa

The pen shell fishery in northwest Mexico is based on reproductive quota, but the reproductive biology of Pinna rugosa, an economically valuable species, has not yet been documented in its main fishery area. The aim of this study was to evaluate the reproductive cycle of P. rugosa, determine the prevalence of atresia and hermaphroditism, and estimate the effect of environmental variables on its reproduction during 2015. Atresia is part of the reproductive cycle in which the cells undergo degeneration. It generally occurs after spawning to reabsorb compounds but it can also occur from the early stages of gametogenesis, affecting fertilization and recruitment. Gonad samples and environmental parameters were collected monthly from a commercial bank at Laguna Ojo de Liebre (Baja California Sur, Mexico) from January to December 2015. Shell height, sex, gonadal development stages, and atresia prevalence were recorded. The results showed that 14% of the individuals were females, 19% were males, and 67% were hermaphrodites, with 3 forms of functional hermaphroditism. Gonadal inactivity occurred in January, February, November, and December, coinciding with lower temperatures and higher chlorophyll a concentrations. Most individuals spawned in June and July. Calculation of a monthly gonad index revealed that gonad development was positively related to environmental variables (R2 = 0.54). Atresia was observed from March to October and was positively related to environmental conditions (R2 = 0.81). The high prevalence of atresia during periods of high temperature and food scarcity suggests that these environmental parameters can affect the reproductive activity of P. rugosa, and have recruitment and fishery productivity implications.

Ultrasound Markers for Complex Gastroschisis: A Systematic Review and Meta-Analysis.

Although gastroschisis is often diagnosed by prenatal ultrasound, there is still a gap in the literature about which prenatal ultrasound markers can predict complex gastroschisis. This systematic review and meta-analysis aimed to investigate the ultrasound markers that characterize complex gastroschisis. A systematic review of the literature was conducted according to the guidelines of PRISMA. The protocol was registered (PROSPERO ID CRD42020211685). Meta-analysis was displayed graphically on Forest plots, which estimate prevalence rates and risk ratios, with 95% confidence intervals, using STATA version 15.0. The combined prevalence of intestinal complications in fetuses with complex gastroschisis was 27.0%, with a higher prevalence of atresia (about 48%), followed by necrosis (about 25%). The prevalence of deaths in newborns with complex gastroschisis was 15.0%. The predictive ultrasound markers for complex gastroschisis were intraabdominal bowel dilatation (IABD) (RR 3.01, 95% CI 2.22 to 4.07; I2 = 15.7%), extra-abdominal bowel dilatation (EABD) (RR 1.55, 95% CI 1.01 to 2.39; I2 = 77.1%), and polyhydramnios (RR 3.81, 95% CI 2.09 to 6.95; I2 = 0.0%). This review identified that IABD, EABD, and polyhydramnios were considered predictive ultrasound markers for complex gastroschisis. However, evidence regarding gestational age at the time of diagnosis is needed.

Effect of fish length and nutritional condition on the fecundity of distressed Atlantic cod Gadus morhua from the Baltic Sea

The disappearance of larger individuals and the decrease in individual body condition suffered by Atlantic cod Gadus morhua in the eastern Baltic during the past two decades can be expected to affect the stock reproductive output. To investigate this, female G. morhua were collected during the spawning and pre-spawning period in 2015-2016. The current individual potential fecundity (FP ) of eastern Baltic G. morhua was estimated and analysed in relation to total length (LT ) and indices of nutritional status such as body condition (K) and hepato-somatic index (IH ) using generalized linear models. In addition, the current prevalence of atresia and its potential relation to K were investigated. Moreover, a calibration curve to estimate FP from oocyte diameter, based on the autodiametric oocyte counting method, was established for the first time for eastern Baltic G. morhua and can be used for future fecundity studies on this stock. The results showed that FP was mainly positively related to fish length, but K and IH also contributed significantly to the variation in FP . The model predicted that fish with K = 1·2 have a FP 51% higher than fish of the same LT with K = 0·8. The prevalence of fecundity regulation by atresia was 5·8%, but it was found only in fish in the pre-spawning maturity stage and with low K. Temporal changes in biological features such as the length composition and individual body condition of eastern Baltic G. morhua, should be accounted for when estimating stock reproductive potential.

Histopathology of brown bullhead (Ameiurus nebulosus), smallmouth bass (Micropterus dolomieu), and yellow perch (Perca flavescens) in relation to polychlorinated biphenyl (PCB) contamination in the Hudson River

From the 1940s through 1977, at least 590,000kg of polychlorinated biphenyls (PCBs) were released into the Hudson River from General Electric manufacturing plants located in Hudson Falls and Fort Edward, New York. In 1984, the U.S. Environmental Protection Agency designated a nearly 322km reach as the Hudson River PCBs Superfund Site. Here we describe a Fish Health Assessment study, part of a Natural Resource Damage Assessment, that evaluated the prevalence of toxicopathic lesions in adult brown bullhead (Ameiurus nebulosus), smallmouth bass (Micropterus dolomieu), and yellow perch (Perca flavescens). In fall 2001, 29–51 fish of each species were collected in fall 2001 from highly contaminated areas below the plants (Thompson Island Pool (TIP) and Stillwater Dam Pool (STW)), an upriver reference area (Feeder Dam Pool (FDP)), and a reference lake, Oneida Lake (ODA). The focus was on histopathologic lesions and observations associated with contaminant exposure: liver—neoplasms, foci of cellular alteration, bile duct hyperplasia; testes—ovotestis (testicular oocytes), germ cell degeneration, altered developmental stage; ovaries—atresia and altered developmental stage. Lesions associated with PCB exposure were defined as those with significantly greater prevalence and/or severity in TIP and STW compared with ODA and FDP. For brown bullhead and smallmouth bass, no lesions or changes in gonadal development met those criteria. In yellow perch, ovarian atresia was the only lesion associated with PCB exposure. Prevalence was 53% in FDP, 75% in ODA, and 100% in both STW and TIP; severity increased from mostly minimal to mild-moderate. Because of the high prevalence of atresia in reference collections, it is likely that factors other than PCBs are also involved. As part of a post–dredging monitoring plan, we recommend assessing gonad structure and function in yellow perch collected at the time of spawning in locations with a range of PCB contamination.

Body reserves mediate trade-offs between life-history traits: new insights from small pelagic fish reproduction.

Limited resources in the environment prevent individuals from simultaneously maximizing all life-history traits, resulting in trade-offs. In particular, the cost of reproduction is well known to negatively affect energy investment in growth and maintenance. Here, we investigated these trade-offs during contrasting periods of high versus low fish size and body condition (before/after 2008) in the Gulf of Lions. Female reproductive allocation and performance in anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) were examined based on morphometric historical data from the 1970s and from 2003 to 2015. Additionally, potential maternal effects on egg quantity and quality were examined in 2014/2015. After 2008, the gonadosomatic index increased for sardine and remained steady for anchovy, while a strong decline in mean length at first maturity indicated earlier maturation for both species. Regarding maternal effects, for both species egg quantity was positively linked to fish size but not to fish lipid reserves, while the egg quality was positively related to lipid reserves. Atresia prevalence and intensity were rather low regardless of fish condition and size. Finally, estimations of total annual numbers of eggs spawned indicated a sharp decrease for sardine since 2008 but a slight increase for anchovy during the last 5 years. This study revealed a biased allocation towards reproduction in small pelagic fish when confronted with a really low body condition. This highlights that fish can maintain high reproductive investment potentially at the cost of other traits which might explain the present disappearance of old and large individuals in the Gulf of Lions.

Fecundity regulation by atresia in turbot Scophthalmus maximus in the Baltic Sea.

Down-regulation of fecundity through oocyte resorption was assessed in Baltic Sea turbot Scophthalmus maximus at three locations in the period from late vitellogenesis in April to spawning during June to July. The mean ± s.d. total length of the sampled fish was 32.7 ± 3.1 cm and mean ± s.d. age was 6.2 ± 1.5 years. Measurements of atresia were performed using the 'profile method' with the intensity of atresia adjusted according to the 'dissector method' (10.6% adjustment; coefficient of determination was 0.675 between methods). Both prevalence (portion of fish with atresia) and intensity (calculated as the average proportion of atretic cells in fish displaying atresia) of atresia were low in prespawning fish, but high from onset of spawning throughout the spawning period. Atretic oocytes categorized as in early alpha and in late alpha state occurred irrespective of maturity stage from late prespawning individuals up to late spawning fish, showing that oocytes may become atretic throughout the spawning period. Observed prevalence of atresia throughout the spawning period was almost 40% with an intensity of c. 20%. This indicates extensive down-regulation, i.e. considerably lower realized (number of eggs spawned) v. potential fecundity (number of developing oocytes), suggesting significant variability in reproductive potential. The extent of fecundity regulation in relation to fish condition (Fulton's condition factor) is discussed, suggesting an association between levels of atresia and fish condition.

Diversity of sexual strategies of fish species caught by bottom trawl off the western Iberian Peninsula

Samples of boarfish Capros aper, small red scorpionfish Scorpaena notata and comber Serranus cabrilla were collected from monthly by-catch samples on board commercial trawlers off the western coast of Portugal. A histological approach was undertaken to study each species’ reproductive strategy and annual sexual cycle. Temporal variations of the gonadosomatic index and of two condition indices (hepatosomatic and Fulton's K) were also analysed. Results showed that C. aper and S. notata are gonochoristic whilst S. cabrilla is a simultaneous hermaphrodite. Fertilization is external and development of secondary growth follicles is asynchronous in the three species. Mass atresia characterized the end of the spawning season in S. notata and S. cabrilla. In C. aper a high prevalence of atresia was observed throughout the year and was not attributed to regressing or regenerating phases or skip spawning events. The main spawning season of the three species was in the summer and it is suggested that spawning is related to upwelling. During the summer, the spawning interval was 1.09, 1.23 and 1.84 days for S. cabrilla, S. notata and C.aper, respectively. The results of this study indicate potential plasticity and environmental adaptation of sexual strategies.

Prevalence of <i>Atresia ani</i> in New Born Calves and Their Surgical Management

This study was conducted in 46 calves to investigate the prevalence of atresia ani/atresia ani et recti in calves at Veterinary Teaching Hospital, & Department of Surgery and Obstetrics, Bangladesh Agricultural University (from June 2009-June 2011) and Shombugong area (Mymensingh District) from January 2008- December 2009. The total percentage of the affections was 23% among the surgical affections in new born calves. The frequency and location of intestinal malformations and gender distribution of affected calves were investigated. The occurrence of atresia ani/ atresia ani et recti in cross bred or indigenous bred were also studied. Atresia ani with or without other intestinal malformations was diagnosed by the Veterinarian at day 1 (25 calves), day 2 (13 calves), day 3-4 (3 calves) and day 5-8 (2 calves) after birth. The affected calves were reported to have been nursed normally immediately after birth but clinical sign became progressively worse with abdominal distension, loss of appetite and abdominal straining. There was no anal opening, but a bulge appeared at its site. Male calves were more frequently affected with atresia ani than those of female calves. The ratio of the male and female affections was approximately 5: 2. The total percentage of indigenous calves affected with atresia ani was 71.74% and the crossbred were 28.26%. Surgical correction is the only successful technique for atresia ani. The prognosis of surgical correction of atresia ani in calves was found good.DOI: http://dx.doi.org/10.3329/bjvm.v12i1.20462 Bangl. J. Vet. Med. (2014). 12 (1): 41-45

Seasonal variability of fecundity and spawning dynamics of Baltic sprat

Seasonal variability in fecundity has been observed in a number of marine fishes and is important towards understanding the reproductive potential of a fish stock. However, the seasonal dynamics of egg production of Baltic sprat (Sprattus sprattus balticus S) have not been well described to date. We present data on the timing of spawning, and the seasonal variability in batch fecundity, number of developing oocytes, oocyte dry weight, spawning fraction, fish condition and atresia for this species in the Bornholm Basin, Baltic Sea. Histological techniques in combination with image analysis were applied to investigate those variables based upon material sampled in 2005 and 2008. Sprat were reported to be in spawning condition from January to June in each year plus in 2008 signs of ovarian maturation were also observed in November. Relative batch fecundity was found to vary two-fold with 85eggsg−1 ovary free body weight observed early in the spawning season (January 2005) and 165eggsg−1 ovary free body weight late in the spawning season (June 2008). Variability in batch fecundity during peak spawning was rather low. A seasonal decrease in oocyte dry weight was related to an increase in batch fecundity. Spawning fraction varied over the course of the spawning period with values ranging from 0.29 in March to 0.18 in June. Stereometric analyses confirmed the indeterminate fecundity of Baltic sprat. Prevalence of atresia was low during peak spawning in April to June (1.0–4.0%) but considerably higher during the early spawning period in March (16.4%) and highest in November (38.5%). Female sprat condition was low during the spawning period and increased sharply after spawning ceased. Our study provides a better understanding of fecundity and spawning dynamics of Baltic sprat which will aid to improve the assessment of reproductive potential of this ecologically and economically important fish species.

Oocyte development and fecundity type of the skipjack, Katsuwonus pelamis, in the Western Indian Ocean

The study aims to define the oogenesis pattern of the skipjack (Katsuwonus pelamis) of the Western Indian Ocean basin in terms of oocyte growth and recruitment style. The main objective is to define the type of fecundity regulation (i.e. determinate or indeterminate) based on four lines of evidence: (a) oocyte size-frequency distribution; (b) seasonal variation of the relative number and percentage of oocyte stages, (c) diameter of the advanced vitellogenic oocytes in females in the spawning capable phase; and (d) incidence of atresia throughout the spawning season. The samples were collected from 2009 to 2010 in the Western Indian Ocean, and 673 ovaries were classified in the different reproductive phases using histological staging. Moreover, the oocyte size distribution of 93 mature individuals was described by the newly implemented image analysis method. This species showed a broad oocyte size frequency distribution with no gap formation between the primary and secondary oocyte growth stages. There was no seasonal variation in the percentage of oocyte stages in ovaries in the spawning capable phase, and the diameter of those oocytes at the most advanced vitellogenic stage was approximately constant during the sampling period. These facts provide evidence of continuous oocyte recruitment into the standing stock of developing oocytes. Moreover, when reaching the end of the active reproductive period (i.e. February and March) the prevalence of atresia increased. This is a mechanism adopted by fishes of the indeterminate fecundity type to reabsorb the surplus oocyte production. Based on the findings, we state that the skipjack in the Western Indian Ocean shows asynchronous oocyte growth and an indeterminate fecundity type.

Epidemiology of small intestinal atresia in Europe: a register-based study

BackgroundThe epidemiology of congenital small intestinal atresia (SIA) has not been well studied. This study describes the presence of additional anomalies, pregnancy outcomes, total prevalence and association with maternal age...

P1-91 Prevalence and temporal trends in the prevalence of small intestinal atresia in Europe: a multilevel analysis

IntroductionSmall intestinal atresia (SIA) is a congenital anomaly characterised by the abnormal closure, discontinuity or narrowing of the duodenum, jejunum or ileum. This study used multilevel regression to examine the...

Atresia de Esófago y sus Asociaciones Preferenciales[title] [title language="en"]Esophageal atresia and related malformations

Esophageal atresia is a congenital malformation incompatible with life. The incidence is quite variable in Chile and all over the world. Objective: To estimate the prevalence at birth of esophageal atresia, comparing with previously published data. Patients and Methods: All children with congenital anomalies born at the UniversityofChile Clinical Hospital from 1999 to 2009 were included. Results: 19.312 births during the study period were registered, 1710 of them had a congenital anomaly (8,9 %). Fifteen of the malformed newborns had esophageal atresia (7.8 x 10.000): one stillbirth and 14 alive newborns. 78,6% of cases were discharge alive from the hospital, 3 (21,4 %) died during the hospitalization. Only 1/15 was an isolated esophageal atresia, 6 cases were syndromic and 9 were classified as VACTERL association. Prenatal diagnosis was made in 73,3 % of the cases. Newborns with esophageal atresia had significantly less birth weight, less gestational age and more malformed relatives, than control newborns. Metrorrhagia during pregnancy in mothers was more frequent in cases than controls. No difference in maternal age between groups was founded. Conclusion: The esophageal atresia prevalence at birth was higher than previously reported local data, and lower than the rest of ECLAMC data; this could be explained because the University of Chile Clinical Hospital is a reference Hospital for prenatal diagnosed cases.

Linking sardine spawning dynamics to environmental variability

The present paper investigates the effect of environmental variability on the spawning dynamics of sardine, Sardina pilchardus, in the Eastern Mediterranean. To do so, variability in four different reproductive traits, i.e. reproductive activity, incidence of recent spawning, prevalence of early ovarian atresia and relative batch fecundity was tested along a gradient of habitat conditions like water temperature, chlorophyll a (Chl a) concentration and an index of zooplankton production. Apart from atretic prevalence all remaining traits were significantly and positively correlated with Chl a concentration which indicates that sardine in the E. Mediterranean tends to enhance egg production under conditions of increased primary productivity. On the other hand, prevalence of atresia together with spawning incidence were positively affected by water temperature whilst the only factor that correlated significantly with the index of zooplankton production was relative fecundity. These findings were interpreted as an indication of direct energy flow from phytoplankton filter-feeding to gonadal development and egg production, implying that besides capitalized energy sardine also uses current income for supporting reproduction.

Seasonal prevalence and intensity of follicular atresia in Baltic cod Gadus morhua callarias L.

In the present study, 307 ovaries of eastern Baltic cod Gadus morhua callarias sampled during the prespawning and spawning season 2000 were analysed histologically to estimate the seasonal prevalence and intensity of atresia. The number of atretic oocytes per ovary was estimated using a combination of the physical disector method and volume fraction (Delesse principle). Atretic oocytes were observed in 32% of the ovaries. Prevalence of atresia was independent of female size, but increased significantly with declining female condition from prespawning and through the spawning stages. The relative intensity of atresia, i.e. number of atretic oocytes in relation to normally developed vitellogenic oocytes, was low amounting to 1·4% on average. Similar to prevalence, relative intensity of atresia differed significantly between maturity stages and increased with decreasing female condition. The population egg loss due to atresia amounted to 4·6% indicating that Baltic cod was performing close to maximum productivity, i.e. potential egg production.

Oocyte growth and fecundity regulation by atresia of Atlantic herring ( Clupea harengus) in relation to body condition throughout the maturation cycle

Oocyte growth, fecundity regulation by resorption of vitellogenic oocytes (atresia), and condition effects on fecundity for repeat spawners (≥32 cm in total length (TL)) of Norwegian spring-spawning (NSS) herring, Clupea harengus, were examined using samples collected periodically from July 1998 to February/March 1999. This period almost covered the maturation cycle of the fish, i.e., 67% (30/45) of the examined fish had started vitellogenesis as early as in July and 18% (7/40) showed hydrated oocytes in February/March. Oocyte diameter increased linearly over time. Average fecundity of 34 cm TL fish decreased by about 56% from 113 000 in July to 49 200 in February/March. Both prevalence of atresia (portion of fish with atresia) and average relative intensity of atresia (prevalence multiplied by geometric mean of relative intensity of atresia among only fish with atresia) were highest in October and November, i.e., following the summer feeding season when fish started to rely on accumulated body reserves. Estimated duration of atresia was 4.5, 6.8, 6.1 and 7.2 d for July–October, October–November, November–January and January–February/March, respectively. Atresia seemed to be limited to oocytes smaller than 1100 μm, which had lipid and solids (protein, ash and carbohydrates) contents that were only half of the values observed for fully matured oocytes (1400–1550 μm). Both the timing of intensive resorption and size of atretic oocytes seemed to optimise fecundity given available energetic reserves. There appeared a highly significant, positive correlation between ovary dry weight, a proxy of reproductive investment, and muscle dry weight condition factor (MDCF; 100×muscle dry weight/TL 3) in the later maturation cycle. Relative fecundity also showed a significant, positive correlation with MDCF in February/March. In conclusion, this study demonstrates important energetic and cellular mechanisms for regulation of reproductive investment in NSS herring females, a long-lived, temperate capital breeder.

Determinacy of fecundity and oocyte atresia in sole (Solea solea) from the Channel, the North Sea and the Irish Sea

Changes in the morphology of the ovary are described during maturation and it is established that it is a homogeneous structure for sampling purposes at maturity stages four and five. Several aspects of vitellogenic oocyte growth and recruitement were examined as criteria to ascertain whether the annual fecundity can be determined in Solea solea just prior to spawning. The first criterion was whether a hiatus develops in the size frequency distribution between the previtellogenic and vitellogenic oocytes just prior to spawning. We were unable to demonstrate this feature in sole from division VIId (N = 5) or IVc (N = 5) but it was present in two out of five fish from division VIIe and all fish examined from division VIIa (N = 5) and IVb west (N = 5). The hiates occurred between 175 and 250 µm (cohort size 25 m) in the size frequency distribution and measured between 25 and 75 µm. Oocyte size frequency distribution from mid spawning and late spawning-spent sole from division IVc showed a hiatus in 9 out of 10 fish which became wider as the residual annual potential fecundity declined. Next the rate of recruitment and growth of vitellogenic oocytes was studied in sole sampled at monthly intervals (July 1993 to February 1994) from division VIId in relation to the start and duration of the annual spawning season. The growth rate of the leading oocyte cohort was 2.73 × 10−5 mm3 per day on 20 September and increased to 3.91 × 10−3 at a mean diameter of 839 µm by 10 February just prior to spawning. However, the observed maximum growth rate, even when adjusted for the positive influence of temperature, allowed little scope for previtellogenic oocytes to complete maturation during a spawning period of 60 days. The recruitment of viltellogenic oocytes was 3013 oocytes per day on 3 August and declined rapidly as spawning approached. In the three months prior to spawning no significant increase was found in the annual potential fecundity. An analysis of a sample of spawning fish from IVc demonstrated that 88% had less than 50% of their predicted potential fecundity remaining in the ovary. The mean batch fecundity was 8 400 (SE ± 13 363) and in conjunction with existing data on spawning frequency and duration gave a realised fecundity close to the potential fecundity. It is concluded that for all practical purposes the sole can be regarded as having a determinate fecundity in all the areas studied.The regulation of potential fecundity by follicular atresia was assessed in pre-spawning and spawning sole. In ICES areas IV and VII the prevalence of atretic oocytes in pre-spawning fish varied between 0.04 and 0.69 and the relative intensity varied between 0.017 and 0.076. During spawning in division IVc the prevalence of atresia varied between 0.45 and 0.57 and the relative intensity between 0.022 and 0.058. If we assume a turnover rate of 9 days the loss from the potential annual fecundity, during spawning, in division IVc would be 12.4%.

Patterns of oocyte development and related changes in plasma 17-β estradiol, vitellogenin, and plasma chemistry in English sole Parophrys vetulus Girard

Ovarian development was monitored in female English sole Parophrys vetulus Girard from three sites in Puget Sound: Sinclair Inlet and Port Susan, where fish are normally resident, and University Point, a known spawning area for English sole. Histological changes in ovary and liver as well as changes in plasma estradiol and vitellogenin levels, gonadosomatic index, hepatosomatic index, and calcium, phosphate, magnesium, glucose, triglyceridesm total protein, and albumin concentrations in the plasma over the reproductive cycle were assessed. Vitellogenesis in female English sole began in the early fall, and swapping activity reached its peak in February. Oocyte development was group synchronous with two distinct clutches of oocytes in the maturing ovary. In general, the cytological and physiological changes which English sole underwent during the reproductive cycle were similar to those observed in other teleost species. However, certain distinctive features were observed, including a high prevalence of atresia of nonyolked oocytes.