Distribution of fish larvae within a weakly tidal mangrove lagoon

2017 ◽  
Vol 68 (2) ◽  
pp. 396
Author(s):  
J. Jaxion-Harm ◽  
M. R. Speight

Mangroves have been shown to provide valuable nursery grounds to juvenile fishes, yet little is known regarding larval distribution and settlement processes in this habitat. To investigate fish larvae in mangrove habitat in a semi-isolated lagoon (surface area 750m2), we employed multiple catch methods: plankton tows, minnow traps, and light traps during June–August 2008 and 2009. Overall, nine families of fish larvae were caught in the light traps. Light traps caught significantly more fish larvae during the new moon compared with the full moon. Plankton tow nets caught early-stage, unidentifiable (without DNA analysis) larvae. Minnow traps only caught a total of three fish larvae. Overall, scarids (parrotfish) and lutjanids (snappers) were the most common larvae from coral-reef fish families and were found at sites over 1km upstream of the mouth of the mangrove lagoon. Without the aid of tidal influence (and nets requiring hydrodynamic force), sampling is difficult in these turbid, shallow waters.

1975 ◽  
Vol 65 (1) ◽  
pp. 81-96 ◽  
Author(s):  
John B. Davies

AbstractThe biting activity of Culex (Melanoconion) portesi Senevet & Abonnenc and C. (M.) taeniopus D. & K. in a secondary seasonal marsh forest in Trinidad was studied by means of catches by six mouse-baited suction traps, and a single light-trap. The traps were cleared at hourly intervals between 17.00 h and 07.00 h on nights which approximated to the new, first quarter, full and last quarter phases of the moon. The catches were compared with illumination at canopy and ground level which was estimated by selenium photocells whose output was recorded on the continuous chart of a servo-potentiometer. Humidity, rainfall, temperature and cloud cover were also recorded. In the suction traps both species showed peaks of activity at evening and dawn twilight at new moon, although the dawn peak was not very pronounced with C. taeniopus, but this pattern was modified on other nights in a manner which was consistent with moon age. At full moon the evening and dawn peaks were replaced by increased activity during moonrise and the middle of the night. The light-traps failed to show the evening and dawn activity and did not always duplicate the baited traps during darkness. Two hypotheses based on either a permissive range of illumination or an underlying circadian rhythm are discussed; neither fully explains the observed biting activity. Although an association between moonlight and biting activity does exist, an understanding of its nature will require more experimental data.


Zoosymposia ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 91-102
Author(s):  
NANCY K. PRENTISS

Nocturnally swarming polychaetes were sampled over a ten-year period (2007–2017) in shallow waters of the Virgin Islands National Park, St. John, United States Virgin Islands. While sampling was qualitative and conducted over different years, months and lunar phases, some patterns were noted in the emergence of swarming polychaetes. Three families (Nereididae, Opheliidae, and Syllidae) had members that swarmed on most nights, while reproductive epitokes from two families appeared only during specific lunar phases: Goniadidae around the full moon and Phyllodocidae around the new moon. Additional polychaete families represented included Amphinomidae, Dorvilleidae, and Scalibregmatidae, whose members swarmed during the waning or waxing lunar phases. This overview offers new information about the timing of reproductive swarming in Caribbean polychaetes and suggests some connections between lunar phases and the swarming of different families.


1979 ◽  
Vol 69 (1) ◽  
pp. 129-139 ◽  
Author(s):  
John Bowden ◽  
Margaret G. Jones

AbstractThe flight activity of adult Delia coarctata (Fall). was studied on Rothamsted Farm from 1969 to 1977 using light-traps. These catch, almost exclusively, dispersing mature females, more being caught at full moon than at new moon. Dispersal begins in response to an acceleration in the rate of decrease of daylength, and at Rothamsted begins on 10 July, soon after the rate of decrease accelerates. Maturation of eggs is controlled by temperature; at Rothamsted, the first mature females appear when temperature accumulation above 5° C has reached 314·5±10·5° after 12 June. Maturation usually coincides with dispersal, but females that have matured before 10 July do not disperse until after that date. Catches of females in light-traps are correlated with the numbers of emerging females per hectare and the numbers of eggs per hectare. Light-traps could be used as a simple way of forecasting numbers of eggs early enough to give advice on seed treatment for winter wheat on land subject to attack by D. coarctata.


2013 ◽  
Vol 13 (3) ◽  
pp. 55-63 ◽  
Author(s):  
Valérie Sarpedonti ◽  
Érica Moema Silva da Anunciação ◽  
Adriana Oliveira Bordalo

Larval fish assemblage in Guajará Bay was studied through four quarterly field campaigns and discussed in relation to individuals' development stages and exposure to contaminants poured out by the Pará State Capital City, Belém. Larval densities were low and diversity extremely poor with a strong dominance of clupeids, engraulids and, to a lower extent, sciaenids. The main spawning season was registered at the onset of the rainy period. Pre-flexion and flexion clupeiforms remained in the farmost stations from the city while post-flexion larvae were found near urban activity centres. Unlikely, pre-flexion and flexion sciaenids were scattered along the city waterfront. Post-flexion larvae were rare; it is suggested that sciaenids use the bay as a transitory route between their spawning grounds and more distant nursery grounds. The waters around the city of Belém showed signs of contamination. However, based on the literature, Guajará Bay environmental quality at the time of the study was suitable for fish larvae life. Nitrate with pH best explained larval distribution.


1975 ◽  
Vol 65 (2) ◽  
pp. 303-348 ◽  
Author(s):  
John Bowden ◽  
Marjory G. Morris

AbstractUsing the inverse square law, estimates can be made of the distances at which illumination from a light-trap is equal to that from background sources. From these distances an index of trap radius can be constructed which can be considered as a measure of trap potential. Between new moon and full moon trap radii vary, depending upon the times of the night at which the trap may be operating, in ratios from about 10:1 to 15:1. A comparable index of light-trap catches can be calculated which allows catches to be examined in relation to changing radius of the trap. Analysis of a series of catches in Uganda and Ghana shows that many species are more abundant than expected in periods of moonlight, particularly at and near full moon, the biggest difference between new moon and full moon being about 10:1 for Marasmia trapezalis (Gn.), whereas the Isoptera, Bostrychidae and Spodoptera triturata (Wlk.) are 3–4 times more frequent at full moon. The ratios between catch at new moon and catch at full moon suggest that the primary determinant of catch is the frequency with which insects cross the boundary of a region of influence whose size is determined by a radius of equal energy. Deductions about the pattern of insect activity through a lunation, and nightly, and the general agreement between curves describing the change in radius of the trap and those of trap catches suggest that changes in catch over a lunation can be explained by changes in the effectiveness of the trap. When corrections are made to allow for such changes, all taxa show some increase in numbers in moonlit periods and in many taxa this increase is substantial. Correction of catches should take account of flight periodicity and this periodicity should, if possible, be confirmed by methods independent of light-traps.


2021 ◽  
pp. 074873042098363
Author(s):  
Alejandro A. Aguirre ◽  
Roberto A. Palomares ◽  
Aitor D. De Ondiz ◽  
Eleazar R. Soto ◽  
Mariana S. Perea ◽  
...  

Evidence has accumulated over the years indicating that the moon influences some aspects of the reproductive activity in animals and humans. However, little is known about the influence of the lunar cycle on the reproductive performance of cows under tropical conditions, where the environment strongly affects reproduction. This retrospective study was conducted with the aim of assessing the influence of the lunar cycle on some reproductive traits of tropical crossbred cows managed in a pasture-based system. Data from 5869 reproductive records from two commercial farms localized in the Maracaibo Lake Basin of Zulia State, Venezuela, were analyzed. Variables studied were first service conception rate, calving frequency, first postpartum estrous frequency, and pregnancy frequency. In addition to the lunar cycle, the effects of farm, season, and predominant breed were also considered. Data were analyzed using logistic regression and general linear model from SAS. First service conception was affected by lunar phases and predominant breed, but not by farm or season. For frequencies of calving, first postpartum estrus, and pregnancy, there was no main effect of farm, season, and predominant breed, whereas the effect of lunar phases was highly significant. First service conception was significantly greater in waning than in crescent phase of the lunar cycle. Frequencies of calving, first estrus, and pregnancy were highly correlated and showed greater figures around full moon and new moon. In conclusion, lunar cycle influenced first service conception, attaining greater values in the waning phase of the moon cycle. Frequencies of calving, first postpartum estrus, and pregnancy in crossbred cows showed a clear bimodal rhythm, whose greatest values coincided with new moon and full moon.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 3043-3043
Author(s):  
Grace Q. Zhao ◽  
Yun Bao ◽  
Heng Wang ◽  
Wanping Hu ◽  
John Coller ◽  
...  

3043 Background: Assessing the genomic and epigenomic changes on plasma cell-free DNA (cfDNA) using next-generation sequencing (NGS) has become increasingly important for cancer detection and treatment selection guidance. However, two major hurdles of existing targeted NGS methods make them impractical for the clinical setting. First, there is no comprehensive, end to end, kit solution available for targeted methylation sequencing (TMS), let alone one that analyzes both mutation and methylation information in one assay. Second, the low yield of cfDNA from clinical blood samples presents a major challenge for conducting multi-omic analysis. Thus, an assay that is capable of both genomic and epigenomic analysis would be advantageous for clinical research and future diagnostic assays. Methods: Here, we report the performance of Point-n-SeqTM dual analysis, a kit solution that can provide in-depth DNA analysis with highly flexible and customizable focused panels to enable both genomic and epigenomic analysis without sample splitting. With custom panels of tens to thousands of markers designed with > 99% first-pass success rate, we conducted both performance validation and multi-center, multi-operator, reproducibility studies. Using spike-in titration of cancer cell-line gDNA with known mutation and methylation profiles, Point-n-Seq assay achieved a reliable detection level down to 0.003% of tumor DNA with a linear relationship between the measured and expected fractions. Benchmarked with conventional targeted sequencing and methylation sequencing, Point-n-Seq solution also demonstrated improved performance, speed and shortened hands-on time. Results: In a pilot clinical study, a colorectal cancer (CRC) TMS panel covering 560 methylation markers and a mutation panel with > 350 hotspot mutations in 22 genes were used in the dual assay. Using 1ml of plasma from late-stage CRC patients, cancer-specific methylation signals were detected in all samples tested, and oncogenic mutations. In an early-stage cohort (33 stage I/II CRC patient ), comparison of the analysis between tumor-informed, personalized-mutation panels (̃100 private SNVs) for each patient and the tumor-independent CRC methylation panels were conducted. The initial results showed that tumor-independent TMS assay achieved a comparable detection compared to the personalized tumor-informed approach. Moreover, cfDNA size information (fragmentome) is also integrated into the analysis of the same Point-n-Seq workflow to improve the assay sensitivity. Conclusions: Point-n-Seq dual analysis is poised to advance both research and clinical applications of early cancer detection, minimal residual disease (MRD), and monitoring.


2017 ◽  
Vol 22 (4) ◽  
pp. 207
Author(s):  
Irwan Jatmiko ◽  
Bram Setyadji ◽  
Arief Wujdi

Madidihang/yellowfin tuna merupakan salah satu jenis ikan tuna ekonomis penting bagi industri perikanan di Indonesia dengan kontribusi hasil tangkapan yang terbanyak. Penelitian ini bertujuan untuk mengetahui pengaruh fase bulan terhadap waktu mulai tebar pancing dan laju tangkap madidihang pada armada rawai tuna. Pengumpulan data dilakukan oleh pemantau ilmiah pada armada rawai tuna yang sebagian besar berbasis di Pelabuhan Benoa, Bali mulai Agustus 2005 hingga Juni 2014. Daerah penangkapan ikan dari armada rawai tuna yang diambil datanya berada di lokasi (lintang dan bujur) 9°-16° LS hingga 109°-120° BT. Analisis anova satu arah dan tes Tukey dilakukan untuk mengetahui pengaruh fase bulan terhadap waktu mulai tebar pancing dan laju tangkap madidihang. Total sebanyak 60 trip dan 1.467 hari operasi penangkapan armada rawai tuna dilakukan dalam penelitian ini. Analisis statistik anova satu arah menunjukkan bahwa terdapat pengaruh yang nyata pada fase bulan terhadap waktu mulai tebar pancing (p<0,05). Selanjutnya, tes Tukey menunjukkan bahwa waktu mulai tebar pancing pada saat bulan purnama dimulai pada pukul 9:00 pagi hari. Waktu ini lebih lambat sekitar 2 jam dari pada waktu mulai tebar pancing pada ketiga fase bulan lainnya (perbani awal, perbani akhir dan bulan baru) yang dilakukan sekitar pukul 7:00 pagi hari. Analisis statistik anova satu arah juga menunjukkan terdapat perbedaan yang nyata antar fase bulan terhadap laju tangkap madidihang (p<0,05). Selanjutnya, tes Tukey menunjukkan bahwa laju tangkap pada saat bulan baru dan perbani awal sebesar 0,13 ekor/100 mata pancing atau lebih besar dibandingkan nilai laju tangkap pada saat purnama dan perbani akhir yang hanya sebesar 0,09 ekor/100 mata pancing. Yellowfin tuna is one of the most economically important species for fisheries industry in Indonesia. The objectives of this study are to investigate the effect of lunar phase to the set time start and catch rate of yellowfin tuna on tuna longline vessels. Data collected by scientific observer on tuna longline vessels mainly based in Benoa Port, Bali from August 2005 to June 2014. Fishing ground of sampled longline tuna located from 9°-16° S to 109°-120° E. One-way anova analysis and Tukey test conducted to examine the effect of lunar phase to the set time start and catch rate of yellowfin tuna. A total of 60 trips and 1,467 fishing days of longline tuna fishing vessels operation have been sampled for in this study. One-way anova analysis showed that there was a significant difference of lunar phase to the set time start (p<0.05). Furthermore, Tukey test showed that the starting time for setting during the full moon begins at 9:00 am. Its time was around 2 hours slower than the start of setting of the other three moon phase (first quarter, last quarter and new moon) which start around 7:00 am. One-way anova analysis also showed that there was a significant difference of lunar phase to catch rate of yellowfin tuna (p<0.05). Furthermore, Tukey test confirmed that hook rate on new moon and first quarter was 0.13/100 hooks or 0.4 bigger than hook rate on full moon and last quarter with only 0.09/100 hooks.


2018 ◽  
Vol 13 (3) ◽  
pp. 219
Author(s):  
Yudha Trinoegraha Adiputra ◽  
Muhammad Zairin Jr. ◽  
Muhammad Agus Suprayudi ◽  
Wasmen Manalu ◽  
Widanarni Widanarni

Pembenihan lobster pasir (Panulirus homarus) belum berkembang di Indonesia karena terbatasnya teknik pemijahan induk dan belum diketahuinya tingkat keberhasilan induk betina membawa telur dan profil telur hasil pemeliharaan. Penelitian bertujuan untuk mempelajari pengaruh ablasi satu tangkai mata, metode pemijahan massal dan individual pada bulan gelap dan terang pada induk berganti kulit dan membawa telur, serta konsentrasi kolesterol dan asam-asam lemak telur pada lama pengeraman berbeda. Induk betina dan jantan dipakai secara terus-menerus saat percobaan pemijahan. Pemijahan pertama menggunakan pemijahan dengan rasio 2:1 pada bulan gelap. Percobaan kedua dan ketiga menggunakan pemijahan massal selama bulan terang dan gelap. Profil telur dibandingkan konsentrasi kolesterol dan asam lemaknya pada 1, 2, dan 3-4 minggu pengeraman. Hasil penelitian menunjukkan ablasi tangkai mata dapat menstimulasi pemijahan individual dan massal yang didahului dengan ganti kulit pada induk betina sebagai indikator pemijahan. Pemijahan massal pada bulan gelap menghasilkan induk betina membawa telur terbanyak dibandingkan pemijahan individual pada bulan gelap dan pemijahan massal pada bulan terang. Konsentrasi kolesterol dan asam-asam lemak telur mengalami perubahan mengikuti lama pengeraman oleh induk yang menunjukkan terjadinya peningkatan kematangan telur (P<0,05).Spiny lobster (Panulirus homarus) hatchery has not been developed in Indonesia. Major constraints were limited broodstock spawning techniques, low incidence of eggs-berried broodstock, and unknown eggs profile. This study aimed to evaluate the effects of eyestalk ablation, spawning methods and moon circulation to molted, the number of eggs berried of females, and eggs-berried cholesterol and fatty acids profiles. Individual and mass spawning during full and new moon were used in this studies. Female and male broodstocks were used for consecutive spawning with ratio 2:1. The first study was used individual spawning during new moon. The second and third studies were used mass spawning during full moon and new moon, respectively. Eggs-berried profile compared concentration of cholesterol and fatty acids during 1, 2, and 3-4 weeks. Results showed eyestalk ablation stimulated individual or mass spawned and molted of female as early indicator of spawning. Full moon and mass spawning supported more eggs-berried female broodstock than that of other methods. Cholesterol and fatty acids showed different concentration within 1, 2, and 3-4 weeks of eggs-berried that supported eggs maturity (P<0.05).


1996 ◽  
Vol 47 (1) ◽  
pp. 67 ◽  
Author(s):  
AJ Courtney ◽  
DJ Die ◽  
JG McGilvray

This study examined the lunar and die1 variation in catch rates and reproductive condition of adult eastern king prawns, Penaeus plebejus, in relatively deep (160 m) coastal waters off south- eastern Queensland. Females numerically dominated catches over most of the lunar cycle and constituted 76% of the weight of the catch. Analysis of variance (ANOVA) revealed an interaction between lunar phase and sex; catches peaked during Lunar Phase 3 (full moon � 3 days) and were particularly marked for males. This was the only period during the lunar cycle when the sex ratio approached 1 : 1. There was also an interaction between trawl-time and sex; male catch rates were at a minimum early in the evening, whereas female catch rates were at a maximum then and declined throughout the night. Trawler logbook catch rate data from the same area over a similar period indicated an interaction between lunar cycle and lunar phase. ANOVA revealed an effect of the interaction between phase and sex on the incidence of soft prawns; the incidence of soft males increased during Phase 4 (half moon waning to new moon � 3 days). Ovary weight also varied between phases and was higher during Phases 2 (half moon waxing to full moon � 3 days) and 4 (half moon waning to new moon � 3 days). Trends in the ovary weight and the incidence of histologically mature and ripe females suggested there are two periods of increased spawning activity during each lunar cycle. A cyclic regression fitted to the data explained 93% of the variation in the incidence of ripe females between samples. The influence of these cyclic trends in catch rate and reproductive condition should be considered when monitoring the spawning stock in the fishery and when planning sampling strategies in any future reproductive studies.


Sign in / Sign up

Export Citation Format

Share Document