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Effects of flowering tree density on the mating system and gene flow in Shorea leprosula (Dipterocarpaceae) in Peninsular Malaysia

Fukue Y, Kado T, Lee SL, Ng KK, Muhammad N, Tsumura Y

J Plant Res, 2007 May;120(3):413-20.
PMID: 17387430

Pristine tropical rainforests in Southeast Asia have rich species diversity and are important habitats for many plant species. However, the extent of these forests has declined in recent decades and they have become fragmented due to human activities. These developments may reduce the genetic diversity of species within them and, consequently, the species' ability to adapt to environmental changes. Our objective in the study presented here was to clarify the effect of tree density on the genetic diversity and gene flow patterns of Shorea leprosula Miq. populations in Peninsular Malaysia. For this purpose, we related genetic diversity and pollen flow parameters of seedling populations in study plots to the density of mature trees in their vicinity. The results show that gene diversity and allelic richness were not significantly correlated to the mature tree density. However, the number of rare alleles among the seedlings and the selfing rates of the mother trees were negatively correlated with the density of the adult trees. Furthermore, in a population with high mature tree density pollination distances were frequently <200 m, but in populations with low adult tree density the distances were longer. These findings suggest that the density of flowering trees affects selfing rates, gene flow and, thus, the genetic diversity of S. leprosula populations. We also found an individual S. leprosula tree with a unique reproductive system, probably apomictic, mating system.

Matched MeSH terms: Reproduction
Effects of non-phthalate plasticizer bis(2-ethylhexyl) sebacate (DEHS) on the endocrine system in Japanese medaka (Oryzias latipes)

Horie Y, Nomura M, Ramaswamy BR, Harino H, Yap CK, Okamura H

Comp Biochem Physiol C Toxicol Pharmacol, 2023 Feb;264:109531.
PMID: 36470400 DOI: 10.1016/j.cbpc.2022.109531

Water pollution due to plasticizers is one of the most severe environmental problems worldwide. Phthalate plasticizers can act as endocrine disruptors in vertebrates. In this study, we investigated whether the non-phthalate bis(2-ethylhexyl) sebacate (DEHS) plasticizer can act as an endocrine disruptor by evaluating changes in the expression levels of thyroid hormone-related, reproduction-related, and estrogen-responsive genes of Japanese medaka (Oryzias latipes) exposed to the plasticizer. Following the exposure, the gene expression levels of thyroid-stimulating hormone subunit beta (tshβ), deiodinase 1 (dio1), and thyroid hormone receptor alpha (trα) did not change. Meanwhile, DEHS suppressed dio2 expression, did not induce swim bladder inflation, and eventually reduced the swimming performance of Japanese medaka. These findings indicate that DEHS can potentially disrupt the thyroid hormone-related gene expression and metabolism of these fish. However, exposure to DEHS did not induce changes in the gene expression levels of kisspeptin 1 (kiss1), gonadotropin-releasing hormone (gnrh), follicle-stimulating hormone beta (fshβ), luteinizing hormone beta (lhβ), choriogenin H (chgH), and vitellogenin (vtg) in a dose-dependent manner. This is the first report providing evidence that DEHS can disrupt thyroid hormone-related metabolism in fish.

Matched MeSH terms: Reproduction
Effects of reproductive status and high ambient temperatures on the body temperature of a free-ranging basoendotherm

Levesque DL, Lobban KD, Lovegrove BG

J. Comp. Physiol. B, Biochem. Syst. Environ. Physiol., 2014 Dec;184(8):1041-53.
PMID: 25155185 DOI: 10.1007/s00360-014-0858-4

Tenrecs (Order Afrosoricida) exhibit some of the lowest body temperatures (T b) of any eutherian mammal. They also have a high level of variability in both active and resting T bs and, at least in cool temperatures in captivity, frequently employ both short- and long-term torpor. The use of heterothermy by captive animals is, however, generally reduced during gestation and lactation. We present data long-term T b recordings collected from free-ranging S. setosus over the course of two reproductive seasons. In general, reproductive females had slightly higher (~32 °C) and less variable T b, whereas non-reproductive females and males showed both a higher propensity for torpor as well as lower (~30.5 °C) and more variable rest-phase T bs. Torpor expression defined using traditional means (using a threshold or cut-off T b) was much lower than predicted based on the high degree of heterothermy in captive tenrecs. However, torpor defined in this manner is likely to be underestimated in habitats where ambient temperature is close to T b. Our results caution against inferring metabolic states from T b alone and lend support to the recent call to define torpor in free-ranging animals based on mechanistic and not descriptive variables. In addition, lower variability in T b observed during gestation and lactation confirms that homeothermy is essential for reproduction in this species and probably for basoendothermic mammals in general. The relatively low costs of maintaining homeothermy in a sub-tropical environment might help shed light on how homeothermy could have evolved incrementally from an ancestral heterothermic condition.

Matched MeSH terms: Reproduction/physiology*
Effects of simulated microgravity on gene expression and biological phenotypes of a single generation Caenorhabditis elegans cultured on 2 different media

Tee LF, Neoh HM, Then SM, Murad NA, Asillam MF, Hashim MH, et al.

Life Sci Space Res (Amst), 2017 Nov;15:11-17.
PMID: 29198309 DOI: 10.1016/j.lssr.2017.06.002

Studies of multigenerational Caenorhabditis elegans exposed to long-term spaceflight have revealed expression changes of genes involved in longevity, DNA repair, and locomotion. However, results from spaceflight experiments are difficult to reproduce as space missions are costly and opportunities are rather limited for researchers. In addition, multigenerational cultures of C. elegans used in previous studies contribute to mixture of gene expression profiles from both larvae and adult worms, which were recently reported to be different. Usage of different culture media during microgravity simulation experiments might also give rise to differences in the gene expression and biological phenotypes of the worms. In this study, we investigated the effects of simulated microgravity on the gene expression and biological phenotype profiles of a single generation of C. elegans worms cultured on 2 different culture media. A desktop Random Positioning Machine (RPM) was used to simulate microgravity on the worms for approximately 52 to 54 h. Gene expression profile was analysed using the Affymetrix GeneChip® C. elegans 1.0 ST Array. Only one gene (R01H2.2) was found to be downregulated in nematode growth medium (NGM)-cultured worms exposed to simulated microgravity. On the other hand, eight genes were differentially expressed for C. elegans Maintenance Medium (CeMM)-cultured worms in microgravity; six were upregulated, while two were downregulated. Five of the upregulated genes (C07E3.15, C34H3.21, C32D5.16, F35H8.9 and C34F11.17) encode non-coding RNAs. In terms of biological phenotype, we observed that microgravity-simulated worms experienced minimal changes in terms of lifespan, locomotion and reproductive capabilities in comparison with the ground controls. Taking it all together, simulated microgravity on a single generation of C. elegans did not confer major changes to their gene expression and biological phenotype. Nevertheless, exposure of the worms to microgravity lead to higher expression of non-coding RNA genes, which may play an epigenetic role in the worms during longer terms of microgravity exposure.

Matched MeSH terms: Reproduction/drug effects
Effects of some environmental parameters on the reproduction and development of a tropical marine harpacticoid copepod Nitocra affinis f. californica Lang

Matias-Peralta H, Yusoff FM, Shariff M, Arshad A

Mar Pollut Bull, 2005;51(8-12):722-8.
PMID: 16291188

The effects of salinity, temperature, and light conditions on the reproduction and development of harpacticoid copepod, Nitocra affinis f. californica under controlled laboratory conditions were determined. Seven different salinity levels (5, 10, 15, 20, 25, 30, 35 ppt), four temperatures (20, 25, 30, 35 degrees C), three different light intensities (25, 56, 130 micromol m(-2) s(-1)) and photoperiods (24 h:0 h, 1 h:23 h, 12 h:12 h LD cycle) were employed in this study. The highest (p < 0.05) overall reproduction and fastest development time were achieved by copepods reared under 30-35 ppt salinity. The optimum temperature required for the maximum reproduction was 30 degrees C while under 30 degrees C and 35 degrees C the copepod development time was shortest (p < 0.05) compared to other temperature levels. The overall reproduction was highest (p < 0.05) and development rate of N. affinis was shortest (p < 0.05) under lowest light intensity (25 micromol m(-2) s(-1)). Continuous light (24 h:0 h LD) inhibited the egg production while, continuous darkness (1 h:23 h LD) and 12 h:12 h LD significantly favoured the overall reproductive activity of the female. Photoperiods 1 h:23 h and 12 h:12 h LD yielded highest total (p < 0.05) offspring female(-1) coupled with highest (p < 0.05) survival percentage. This study illustrated that although N. affinis can tolerate wide range of environmental conditions, prolonged exposure to subnormal environments affect its reproduction and development. This study showed that this species can be mass cultured for commercial purposes and has a potential to be used for toxicity studies due to its high reproductive performance fast development and a wide range of tolerance to environmental conditions.

Matched MeSH terms: Reproduction/physiology
Fulltext Environmental and Genetic Traffic in the Journey from Sperm to Offspring

Sengupta P, Dutta S, Liew FF, Dhawan V, Das B, Mottola F, et al.

Biomolecules, 2023 Dec 07;13(12).
PMID: 38136630 DOI: 10.3390/biom13121759

Recent advancements in the understanding of how sperm develop into offspring have shown complex interactions between environmental influences and genetic factors. The past decade, marked by a research surge, has not only highlighted the profound impact of paternal contributions on fertility and reproductive outcomes but also revolutionized our comprehension by unveiling how parental factors sculpt traits in successive generations through mechanisms that extend beyond traditional inheritance patterns. Studies have shown that offspring are more susceptible to environmental factors, especially during critical phases of growth. While these factors are broadly detrimental to health, their effects are especially acute during these periods. Moving beyond the immutable nature of the genome, the epigenetic profile of cells emerges as a dynamic architecture. This flexibility renders it susceptible to environmental disruptions. The primary objective of this review is to shed light on the diverse processes through which environmental agents affect male reproductive capacity. Additionally, it explores the consequences of paternal environmental interactions, demonstrating how interactions can reverberate in the offspring. It encompasses direct genetic changes as well as a broad spectrum of epigenetic adaptations. By consolidating current empirically supported research, it offers an exhaustive perspective on the interwoven trajectories of the environment, genetics, and epigenetics in the elaborate transition from sperm to offspring.

Matched MeSH terms: Reproduction/genetics
Epitokous metamorphosis, reproductive swimming, and early development of the estuarine polychaete, Neanthes glandicincta Southern, 1921 (Annelida, Nereididae) on the east coast of the Malay Peninsula

Azmi SS, Ibrahim YS, Angsupanich S, Sumpuntarat P, Sato M

Zookeys, 2021;1011:1-24.
PMID: 33551646 DOI: 10.3897/zookeys.1011.59780

The reproductive and developmental characteristics of the nereidid polychaete, Neanthes glandicincta Southern, 1921, commonly recorded in tropical estuaries in the Indo-West Pacific, were examined from Malaysia (the mangrove area of Kuala Ibai, Terengganu) and Thailand (the Lower Songkhla Lagoon) on the east coast of the Malay Peninsula. Epitokous metamorphosis of fully mature males and females and their reproductive swimming behaviour were recorded based on ten Malaysian epitokous specimens, which were collected at night during spring tides in a period of January 2018 to March 2019. Six Thailand epitokes were obtained in February and March 2006 by the laboratory rearing of immature worms. Epitokous metamorphosis is characterised by the enlargement of eyes in both sexes, division of the body into three parts and modification of parapodia with additional lobes in the mid-body of males, and replacement of atokous chaetae in the mid-body by epitokous natatory chaetae, completely in males and incompletely in females. The diameter of coelomic unfertilised eggs in females was 100-140 µm. After fertilisation, each egg formed a jelly layer, inside which embryonic development progressed. Trochophores hatched out of the jelly layer, entering a short free-swimming larval phase followed by demersal life at the early stage of 3-chaetiger nectochaeta one day after fertilisation. Then, the larvae entered benthic life as juveniles, crawling on the bottom, at the late stage of 3-chaetiger nectochaeta two days after fertilisation. The results indicate that N. glandicincta has an annual life cycle, which is usually completed within an estuary with limited larval dispersal ability.

Matched MeSH terms: Reproduction
Fulltext Ethics in assisted human reproduction

Arshat H

Med J Malaysia, 1989 Mar;44(1):1-2.
PMID: 2626107
Matched MeSH terms: Reproduction*
Fulltext Evaluation of inverter reliability performance due to negative bias temperature instability (NBTI) effects in advance CMOS technology nodes

Zainudin, M.F., Hussin, H., Halim, A.K.

Pertanika Journal of Science & Technology, 2017;25(101):295-304.
MyJurnal

Negative bias temperature instability (NBTI) is the most concern issue CMOS devices with the scaling
down of the CMOS technologies. NBTI effect contributes to P-MOSFET device degradation which later
reduce the performance and reliability of CMOS circuits. This paper presents a reliability simulation study
based on R-D model on CMOS inverter circuit. HSPICE MOSRA model together with the Predictive
Technology Model (PTM) was used as to incorporate the NBTI model in the circuit reliability simulation
study for different technology nodes. PTM of High Performance (HP) models of 16nm, 22nm, 32nm
and 45nm were used in this simulation study. The atomic hydrogen based model was integrated in the
simulation. The results show that in a CMOS inverter circuit, the threshold voltage shift of p-MOSFET
under NBTI stressing increased as the year progressed.. The threshold voltage shift was observed to
increase up to 45.1% after 10 years of operation. The time exponent, n ~ 0.232 of the threshold voltage
shift observed indicates that the defect mechanism contributed to the degradation is atomic hydrogen.
The propagation delay increased to 19.5% over a 10-year period. s up to 19.5% from the zero year
of operation until 10 years of the operation. In addition, the time propagation delay increased as year
increased when the technology nodes smaller. The finding is important for understanding reliability
issues related to advanced technology nodes in CMOS circuits study.

Matched MeSH terms: Reproduction
Fulltext Evaluation of two cell culture media in culturing rat full term amniotic fluid cells

Ferdaos, N., Karuppiah, T., Rosli, R., Yazid, M. N., Nordin, N.

Malaysian Journal of Medicine and Health Sciences, 2011;7(2):81-85.
MyJurnal

Introduction: Amniotic fluid (AF) consists of heterogenous population of cells with high diagnostic
and therapeutic values. The study of rat amniotic fluid cells is very limited, despite the extensive use
of this animal model in biomedical research. Primary culture of rat AF cells, especially from full term pregnancies has not been well established. Here we attempt to determine the suitable medium in
culturing rat AF cells that would enhance the cell viability, growth rate and heterogeneity. Methods:
The cell viability, growth rate and heterogeneity of rat AF cells were compared upon culturing the
primary cells in two different media; Amniomax or RPMI. Cell viability study was carried out using
trypan blue staining, while the growth rate was monitored based on the time required to passage the cells (population doubling time in hour). The heterogeneity of cells was examined based on the morphology of the cells. Statistical analysis was performed using t-test. Results: Amniomax was observed to provide a better culture condition in culturing rat AF cells as the cells are more viable, grow faster and more heterogenous as compared to the cells grown in RPMI. Conclusion: Amniomax is a more suitable medium for high quality and viability of full term rat AF cell culture, as compared to RPMI. Thus, warranting propagation of more rat AF cells for biomedical research.

Matched MeSH terms: Reproduction
Evidence for high gene flow, nonrandom mating, and genetic bottlenecks of Ganoderma boninense infecting oil palm (Elaeis guineensis Jacq.) plantations in Malaysia and Indonesia

Wong WC, Tung HJ, Nurul Fadhilah M, Midot F, Lau SYL, Melling L, et al.

Mycologia, 2022;114(6):947-963.
PMID: 36239960 DOI: 10.1080/00275514.2022.2118512

Ganoderma boninense, the causal agent of basal stem rot (BSR) disease, has been recognized as a major economic threat to commercial plantings of oil palm (Elaeis guineensis Jacq.) in Southeast Asia, which supplies 86% of the world's palm oil. High genetic diversity and gene flow among regional populations of 417 G. boninense isolates collected from Sabah, Sarawak, and Peninsular Malaysia (Malaysia) and Sumatra (Indonesia) were demonstrated using 16 microsatellite loci. Three genetic clusters and different admixed populations of G. boninense across regions were detected, and they appeared to follow the spread of the fungus from the oldest (Peninsular Malaysia and Sumatra) to younger generations of oil palm plantings (Sabah and Sarawak). Low spatial genetic differentiation of G. boninense (FST = 0.05) among the sampling regions revealed geographically nonrestricted gene dispersal, but isolation by distance was still evident. Analysis of molecular variance (AMOVA) confirmed the little to no genetic differentiation among the pathogen populations and the three genetic clusters defined by STRUCTURE and minimum spanning network. Despite G. boninense being highly outcrossing and spread by sexual spores, linkage disequilibrium was detected in 7 of the 14 populations. Linkage disequilibrium indicated that the reproduction of the fungus was not entirely by random mating and genetic drift could be an important structuring factor. Furthermore, evidence of population bottleneck was indicated in the oldest oil palm plantations as detected in genetic clusters 2 and 3, which consisted mainly of Peninsular Malaysia and Sumatra isolates. The population bottleneck or founding event could have arisen from either new planting or replanting after the removal of large number of palm hosts. The present study also demonstrated that migration and nonrandom mating of G. boninense could be important for survival and adaptation to new palm hosts.

Matched MeSH terms: Reproduction
Evidence of plasmotomy in Blastocystis hominis

Tan TC, Suresh KG

Parasitol Res, 2007 Nov;101(6):1521-5.
PMID: 17701428

Blastocystis hominis has been regarded as an enigmatic parasite as many aspects of its basic biology remain uncertain. Many reproductive processes have been suggested for the organism; however, to date, only the binary fission has been proven. Plasmotomy is one of the modes of reproduction previously suggested to be seen in in vitro cultures. The present study provides trichrome and acridine orange staining evidence for the existence of nucleic acid suggestive of division of nucleus into multinucleate forms with the respective cytoplasm dividing giving rise to two or three progeny B. hominis. Transmission electron micrographs further confirmed that these daughter cells had respective surrounding surface coat, mitochondria, and vacuoles.

Matched MeSH terms: Reproduction, Asexual/physiology*
Experimental data on glucose and energy levels of orange mud crab, Scylla olivacea at different water velocities

Taufik M, Amin-Safwan A, Mohd Nordin AR, Shahrul I, Abol-Munafi AB, Ikhwanuddin M

Data Brief, 2020 Apr;29:105232.
PMID: 32099875 DOI: 10.1016/j.dib.2020.105232

The present datasets were conducted to investigate glucose concentration in hemolymph, energy levels at selected body parts (hepatopancreas, muscle, gonad), and feces among different sexes of crabs cultured at four different water velocities (0, 20, 40, and 60 cm/s) during a 60-day culture period. A total of 102 immature crabs (51 males, and 51 females) were sampled from Kuala Muda, Kedah coastal water, Peninsular Malaysia (5°39'N 100°19'E) from April to November of 2018. Results indicated that glucose concentration was the highest at water velocity of 60 cm/s for both male and female crabs (♂: 3.76 ± 0.08 mmol/L; ♀: 3.63 ± 0.06 mmol/L), whereas at 0 cm/s, the lowest levels of glucose concentration (♂: 0.13 ± 0.08 mmol/L; ♀: 0.19 ± 0.06 mmol/L) were recorded. As for energy analysis in hepatopancreas, results showed that both male and female crabs recorded the highest levels at 0 cm/s (no flow) with 37.919 ± 0.07 KJ/g and 34.636 ± 0.50 KJ/g, respectively. Energy for locomotion (muscle) of male crabs recorded the highest at 0 cm/s (♂: 26.823 ± 0.06 KJ/g), meanwhile for females, the highest was recorded at 20 cm/s (26.607 ± 0.34 KJ/g). Energy for reproduction of males could not be compared due to an insufficient available amount of testes/vas deferens, whereas female crabs recorded the highest energy usage at 20 cm/s water velocity (♀: 37.895 ± 0.08 KJ/g). For feces, both male and female crabs recorded the lowest energy at 60 cm/s (♂: 5.841 ± 0.03 KJ/g; ♀: 5.393 ± 0.01 KJ/g). Glucose assessment showed a direct relationship between increased velocity and glucose secretion in hemolymph at high velocity of 60 cm/s (stress condition) compared to other treatments. Regarding energy analysis, this research improved the mechanism of hepatopancreas, gonad, muscle and feces functions in development and reproduction, while it shed light on the influence of velocity on energy metabolism of S. olivacea.

Matched MeSH terms: Reproduction
Fulltext Exploring women's perceptions and experiences of menopause among East Coast Malaysian women

Mohamad Ishak NN, Jamani NA, Mohd Arifin SR, Abdul Hadi A, Abd Aziz KH

Malays Fam Physician, 2021 Mar 25;16(1):84-92.
PMID: 33948146 DOI: 10.51866/oa1098

Background: Menopause signifies the beginning of a non-reproductive phase from the reproductive period. Although it is considered a natural life transition, recent studies have indicated that a woman's menopausal experience may impact her quality of life. While studies have examined Malaysian women's knowledge and awareness of menopause, they have focused on the prevalence of menopausal symptoms and sociocultural aspects. These investigations also used a quantitative design that may have limited the information regarding the nature and experience of menopause. Objectives: This study explores women's perceptions and understanding of their menopausal experience.
Methods: A total of 20 menopausal women were recruited using purposive sampling through social media in the state of Pahang, Malaysia. In-depth semi-structured interviews were used to explore how they perceived their menopausal experience. The data were then analyzed using thematic analysis.
Results: Three themes that emerged from the findings included perceptions of menopause, biopsychosocial changes and help-seeking behavior. For many Muslim women, menopause was perceived as a time for them to engage in religious commitment more than they had before.
Conclusion: The study findings uncovered a knowledge gap and a lack of support for women impacted by menopause. Muslim women regarded their menopause phase as a time for them to engage in religious duty fully. These results indicate the need for a psychosocial intervention and educational program to ensure women a better transition throughout their menopausal phase.

Matched MeSH terms: Reproduction
Fulltext Father absence and reproduction-related outcomes in Malaysia, a transitional fertility population

Sheppard P, Snopkowski K, Sear R

Hum Nat, 2014 Jun;25(2):213-34.
PMID: 24610662 DOI: 10.1007/s12110-014-9195-2

Father absence is consistently associated with children's reproductive outcomes in industrialized countries. It has been suggested that father absence acts as a cue to particular environmental conditions that influence life history strategies. Much less is known, however, about the effects of father absence on such outcomes in lower-income countries. Using data from the 1988 Malaysian Family Life Survey (n = 567), we tested the effect of father absence on daughters' age at menarche, first marriage, and first birth; parity progression rates; and desired completed family size in Malaysia, a country undergoing an economic and fertility transition. Father absence during later childhood (ages 8 to 15), although not during earlier childhood, was associated with earlier progressions to first marriage and first birth, after controlling for other confounders. Father absence does not affect age at menarche, desired family size, or progression from first to second birth. The patterns found in this transitional population partly mirror those in developed societies, where father absence accelerates reproductive events. There is, however, a notable contrast between the acceleration in menarche for father-absent girls consistently found in developed societies and the lack of any association in our findings. The mechanisms through which father absence affects reproduction may differ in different ecological contexts. In lower-income contexts, direct paternal investment or influence may be of more importance in determining reproductive behavior than whether fathers act as a cue to environmental conditions.

Matched MeSH terms: Reproduction/physiology*
Fecundity, embryonic and ovarian development of blue swimming crab, Portunus pelagicus (Linnaeus, 1758) in coastal water of Johor, Malaysia

Ikhwanuddin M, Azra MN, Siti-Aimuni H, Abol-Munafi AB

Pak J Biol Sci, 2012 Aug 01;15(15):720-8.
PMID: 24171257

Blue swimming crab, Portunus pelagicus is widely study and research throughout the Indo-West Pacific, but little is known of its reproductive biology in Malaysia. The present study describes the fecundity, embryonic development and ovarian development stages of the P. pelagicus from Johor coastal water, Malaysia. Carapace width range of berried crabs sampled was from 9.64 to 13.32 cm, while the body weight range was from 75 to 235 g. The mean number of egg produced by females in different sizes ranged from 105443.333 +/- 35448.075 per eggs batch. Mean egg size during embryonic development at stage 1 was 0.307 +/- 0.037, while 0.386 +/- 0.039 and 0.396 +/- 0.033 for stage 2 and stage 3, respectively. Study showed that there was significant (p < 0.05) relationship between the number of eggs and carapace width/body weight. Mean diameter oocyte during ovarian development at stage 1 was 97.732 +/- 12.391 while for stage 2 was 149.516 +/- 23.287. Stage 3 showed increasingly of size with mean diameter was 158.506 +/- 27.616 and 181.013 +/- 24.339 for stage 4.

Matched MeSH terms: Reproduction/physiology
Fecundity, fertility and survival of red palm weevil (Rhynchophorus ferrugineus) larvae reared on sago palm

Wahizatul Afzan Azmi, Yong Kah Wai, Aisyah Abu Bakar

Sains Malaysiana, 2015;44:1371-1375.

AISYAH ABU BAKARRed palm weevil (RPW), Rhynchophorus ferrugineus has been reported as a serious pest of coconut, sago palm and date palm in many parts of the world. In Malaysia, RPW is a lethal pest of coconut in Terengganu and sago palm in Sarawak. However, very limited information about the reproductive performance of RPW is available, specifically in Malaysia. In the present study, the reproductive performance of RPW reared on sago palm (Metroxylon sagu) were studied using nine pairs of virgin RPW under laboratory conditions. The number of eggs laid and eggs viability were recorded daily until females could not produce eggs. The total number of eggs laid were 3081 and the average number of eggs deposited by a female was 342.3+0.97 eggs (ranged from 270 to 396). The percentage of hatchability was 52.4% and out of the total 1614 hatched eggs, only 118 individuals (7.3%) were survived until late instar. However, no significant differences in fecundity, hatchability and total survived larvae in different RPW pairs were observed. Females longevity was found to be strongly influenced by the number of eggs laid; the higher number of eggs laid, the shorter is the life span of the female. This study is important to understand the biological aspects of RPW, as a first step to develop effective control strategy of the pest.

Matched MeSH terms: Reproduction
Fulltext Feeding ecology and reproductive biology of small coastal sharks in Malaysian waters

Lim KC, Then AY, Loh KH

PeerJ, 2023;11:e15849.
PMID: 37637173 DOI: 10.7717/peerj.15849

Small coastal demersal sharks form a major proportion of the sharks landed in Malaysia. However, little is known about their feeding ecology and reproduction. This study sought to elucidate the dietary patterns, role of ontogeny in prey consumption, and reproductive biology of four dominant small demersal shark species in Malaysian waters: the Hasselt's bamboo shark, Chiloscyllium hasseltii; brownbanded bamboo shark, C. punctatum; spadenose shark, Scoliodon laticaudus; and Pacific spadenose shark, S. macrorhynchos. Dietary analyses revealed a high overlap in prey taxa consumed; clear resource partitioning among co-occurring species based on the percentage Prey-specific Index of Relative Importance (%PSIRI), with higher fish %PSIRI for Chiloscyllium hasseltii, higher cephalopod %PSIRI for C. punctatum, and higher crustacean %PSIRI for both Scoliodon species; and an ontogenetic diet shift, seen through changes in prey size. Based on the examination of reproductive organs, the results showed larger sizes at maturity for males compared to females for all four species; no obvious reproductive cycles, based on hepatosomatic and gonadosomatic indices for all species; female bias in the sex ratio of the embryos of Scoliodon species; and increased reproductive output (number of eggs or embryos and size of eggs) with larger female size for C. hasseltii and Scoliodon species. The partitioning of food resources minimizes direct competition for food and supports coexistence within shared coastal habitats. The reproductive strategies of these small coastal sharks appear to be favorable for supporting short-term population productivity; although a reduction in fishing pressure, especially from bottom trawlers, is essential for the long-term sustainable use of these sharks.

Matched MeSH terms: Reproduction*
Fulltext Female tilapia, Oreochromis sp. mobilised energy differently for growth and reproduction according to living environment

Razali RS, Rahmah S, Shirly-Lim YL, Ghaffar MA, Mazelan S, Jalilah M, et al.

Sci Rep, 2024 Feb 05;14(1):2903.
PMID: 38316820 DOI: 10.1038/s41598-024-52864-0

This study was conducted to investigate the energy mobilisation preference and ionoregulation pattern of female tilapia, Oreochromis sp. living in different environments. Three different treatments of tilapia as physiology compromising model were compared; tilapia cultured in recirculating aquaculture system (RAS as Treatment I-RAS), tilapia cultured in open water cage (Treatment II-Cage) and tilapia transferred from cage and cultured in RAS (Treatment III-Compensation). Results revealed that tilapia from Treatment I and III mobilised lipid to support gonadogenesis, whilst Treatment II tilapia mobilised glycogen as primary energy for daily exercise activity and reserved protein for growth. The gills and kidney Na+/K+ ATPase (NKA) activities remained relatively stable to maintain homeostasis with a stable Na+ and K+ levels. As a remark, this study revealed that tilapia strategized their energy mobilisation preference in accessing glycogen as an easy energy to support exercise metabolism and protein somatogenesis in cage culture condition, while tilapia cultured in RAS mobilised lipid for gonadagenesis purposes.

Matched MeSH terms: Reproduction
Fulltext First record of multi-species synchronous coral spawning from Malaysia

Chelliah A, Amar HB, Hyde J, Yewdall K, Steinberg PD, Guest JR

PeerJ, 2015;3:e777.
PMID: 25737817 DOI: 10.7717/peerj.777

Knowledge about the timing and synchrony of coral spawning has important implications for both the ecology and management of coral reef ecosystems. Data on the timing of spawning and extent of synchrony, however, are still lacking for many coral reefs, particularly from equatorial regions and from locations within the coral triangle. Here we present the first documentation of a multi-species coral spawning event from reefs around Pulau Tioman, Peninsular Malaysia, a popular diving and tourist destination located on the edge of the coral triangle. At least 8 coral species from 3 genera (Acropora, Montipora and Porites) participated in multi-species spawning over five nights in April 2014, between two nights before and two nights after the full moon. In addition, two Acropora species were witnessed spawning one night prior to the full moon in October 2014. While two of the Acropora species that reproduced in April (A. millepora and A. nasuta) exhibited highly synchronous spawning (100% of sampled colonies), two other common species (A. hyacinthus and A. digitifera) did not contain visible eggs in the majority of colonies sampled (i.e., <15% of colonies) in either April or October, suggesting that these species spawn at other times of the year. To the best of our knowledge, this is the first detailed documented observation of multi-species coral spawning from reefs in Malaysia. These data provide further support for the contention that this phenomenon is a feature of all speciose coral assemblages, including equatorial reefs. More research is needed, however, to determine the seasonal cycles and extent of spawning synchrony on these reefs and elsewhere in Malaysia.

Matched MeSH terms: Reproduction

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