Turtle Eggs Research Articles

Empowering the Rural Community as Turtle Breeder: Case Studi of Dunu Village, Gorontalo Utara Regency

Turtles are marine reptiles that have existed on Earth for millions of years and have managed to survive until today. Turtles play a crucial role in the marine ecosystem, maintaining the balance of nature and contributing to marine biodiversity. The method used in this research is a qualitative approach, which includes conducting in-depth interviews, participatory observations, and analyzing relevant documents. The data obtained will be analyzed using descriptive and interpretative approaches to illustrate the process of empowering the rural community in Dunu Village. This research aims to understand how the empowerment of the Dunu village community as turtle breeders takes place. The study was conducted for a duration of two weeks, starting from June 27, 2023, to July 11, 2023. The research findings indicate that in Dunu village, Gorontalo Utara Regency, three types of turtles are being conserved. The turtle species involved are the green turtle (Chelonia mydas), hawksbill turtle (Eretmochelys imbricata), and olive ridley turtle (Lepidochelys olivacea). There are two individuals from Dunu village who are recognized as professional turtle breeders and actively participate in the protection of turtle eggs, caring for hatchlings, and conducting patrols along the beach where the turtles nest. These two breeders received training from the Balai Konservasi Sumber Daya Alam (BKSDA) Sulawesi Utara through the Seksi Konservasi Wilayah II Gorontalo.

Sea turtle egg yolk and albumen as biomonitoring matrices for maternal burdens of organic pollutants

To establish the use of eggs as biomonitoring tools for maternal body burdens, we investigated the mother-to-egg ratio of 56 PCB, 12 OCP and 34 PBDE unique compounds from maternal plasma into replicate egg yolk and albumen samples in the loggerhead turtle (Caretta caretta) as a case study of a threatened migratory marine species. We applied robust Regression on Order Statistics to fully account for the information in both censored and uncensored data. Our results added new insights into the use of yolk as a suitable biomonitoring matrix; the difference between yolk and albumen which were previously analysed as a homogeneous mixture; and the value of accounting for censored data. Overall, compound-specific mother-to-egg ratios need to be considered when translating yolk levels back to maternal pollution burdens, and when assessing the risk to the subsequent generations of turtle embryos.

Development and evaluation of a medium-free incubation method for hatching Chinese soft-shelled turtle (Pelodiscus sinensis) eggs

In aquaculture, the traditional method for hatching Pelodiscus sinensis eggs needs further investigation. Here, we developed a medium-free incubation method for hatching P. sinensis eggs and evaluated its differences from the traditional vermiculite incubation method and the effects of light on it. We found that medium-free incubation had no significant effects on hatching success, body weight, carapace length, carapace width, plastron length, plastron width, and righting response time of P. sinensis compared with those under traditional vermiculite incubation, irrespective of thermostatic or fluctuating temperature conditions. Furthermore, light treatment significantly shortened the incubation period and negatively affected body weight, carapace length, carapace width, plastron length, and righting response time during medium-free incubation. Additionally, this study is the first to report the phenomenon of egg-hatching synchrony in P. sinensis. Overall, our results provide basic data and novel insights for improving the method for hatching P. sinensis eggs.

Cross-Linking of White Proteins in Soft-Shell Turtle Eggs Using Transglutaminase, Reductant, and Thermal Pretreatment

The effects of transglutaminase (TGase), reductant, and thermal treatment on the cross-linking of white proteins in soft-shell turtle eggs were investigated. Egg white proteins were denatured by reductant (0.83% 2-mercaptoethanol, 2-ME) pretreatment and thermal pretreatment (95 °C and 5 min), and the denatured proteins were then catalyzed by TGase (1.0 unit/mL). SDS–PAGE showed that without any pretreatments, three major egg white proteins (210 kDa, 115 kDa, and 76 kDa proteins) were inferior substrates for TGase. Only portions of the 210 kDa protein (7.9%), 115 kDa protein (11.4%), and 76 kDa protein (42.9%) were polymerized by TGase into high-molecular-weight (MW) protein polymers (>180 kDa) after incubation for 3 h at 40 °C. However, the combined use of TGase with 0.83% 2-ME and thermal pretreatment led to a significant increase (p < 0.05) in the rate of white protein polymerization after 3 h: 210 kDa protein (90.8%), 115 kDa protein (69.5%), and 76 kDa protein (72.2%). Particle size analysis indicated that these cross-linked high-MW protein polymers were 2000–10,000 nm in size. Based on the experimental results, egg white proteins denatured by 2-ME and heat pretreatment are more prone to TGase-induced cross-linking.

Estimating the size of densely packed and complex grains using valley edge detection with a one-pixel width and grain shape information

This study proposes a novel image segmentation algorithm for estimating the average size of densely packed grains, particles, cells, powders, bubbles, and aggregates. The algorithm comprises two sub-algorithms: valley edge detection and grain size estimation. The valley edge detection sub-algorithm identifies weak edges among grains using four directions. In contrast, the grain size estimation sub-algorithm calculates the average size of the grains based on the detected edge density. The algorithm can recognize grains with circular, elliptical, or other regular shapes without explicitly delineating each grain, making it ideal for complex and densely packed grain images. The algorithm was tested using various samples, including aggregate particles, tomatoes, chicken/duck eggs, turtle eggs, soybeans, lawn seeds, rapeseeds, and other seeds, and the testing results were satisfactory. The proposed algorithm is 200-500 times faster than ordinary grain image segmentation algorithms. It is suitable for online applications that require real-time image processing of densely packed and detailed grain images.

Potential impacts of environmental bacteria on the microbiota of loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtle eggs and their hatching success.

Sea turtle hatching success can be affected by many variables, including pathogenic microbes, but it is unclear which microbes are most impactful and how they are transmitted into the eggs. This study characterized and compared the bacterial communities from the (i) cloaca of nesting sea turtles (ii) sand within and surrounding the nests; and (iii) hatched and unhatched eggshells from loggerhead (Caretta caretta) and green (Chelonia mydas) turtles. High throughput sequencing of bacterial 16S ribosomal RNA gene V4 region amplicons was performed on samples collected from 27 total nests in Fort Lauderdale and Hillsboro beaches in southeast Florida, United States. Significant differences were identified between hatched and unhatched egg microbiota with the differences caused predominately by Pseudomonas spp., found in higher abundances in unhatched eggs (19.29% relative abundance) than hatched eggs (1.10% relative abundance). Microbiota similarities indicate that the nest sand environment, particularly nest distance from dunes, played a larger role than the nesting mother's cloaca in influencing hatched and unhatched egg microbiota. Pathogenic bacteria potentially derive from mixed-mode transmission or additional sources not included in this study as suggested by the high proportion (24%-48%) of unhatched egg microbiota derived from unknown sources. Nonetheless, the results suggest Pseudomonas as a candidate pathogen or opportunistic colonizer associated with sea turtle egg-hatching failure.

Fungal infection of sea turtle eggs in the sea turtle hatcheries in Peninsular Malaysia

Fungal infection of sea turtle eggs in the sea turtle hatcheries in Peninsular Malaysia

Embryonic development, hatchling performance and metabolic profile after egg exposure to environmentally relevant levels of chlorpyrifos in an aquatic turtle

The extensive use of organophosphorus insecticides poses a threat to the survival of non-target organisms. Ecotoxicological outcomes of embryonic exposure to insecticides are rarely evaluated in various oviparous species. In this study, soft-shelled turtle (Pelodiscus sinensis) eggs were incubated in moist substrate containing different levels (0, 2, 20 and 200 μg/kg) of chlorpyrifos to investigate its toxic effects on embryonic development and survival, and hatchling physiological performance. Chlorpyrifos exposure had no significant impacts on embryonic development rate and egg survival in P. sinensis. Similarly, embryonic chlorpyrifos exposure neither obviously affected the size and locomotor performance of hatchlings, nor changed the activities of superoxide dismutase and catalase, and content of malondialdehyde in their erythrocytes. Based on liquid chromatography-mass spectrometry analysis, minor metabolic perturbations related to amino acid, lipid and energy metabolism in hatchlings after embryonic chlorpyrifos exposure were revealed by hepatic metabolite profiling. Overall, our results suggested that embryonic exposure to environmentally relevant levels of chlorpyrifos had only a limited impact on physiological performances of hatchlings, although it would result in a potential risk of hepatotoxicity in P. sinensis.

Seasonal Food Habit Variation of Sloth Bear (Melursus ursinus) in Feeding Turtle Eggs in Kasibugga Range of Srikakulam District, of Andhra Pradesh

Seasonal Food Habit Variation of Sloth Bear (Melursus ursinus) in Feeding Turtle Eggs in Kasibugga Range of Srikakulam District, of Andhra Pradesh

Impact assessment of severe cyclonic storm Asani on the nesting grounds of Olive Ridley turtle, Rushikulya Estuary and spit in Odisha state, India

The objective of this study is to understand the impact of cyclone Asani on the coastal dynamics and nesting grounds of Olive Ridley sea turtles in the Rushikulya Estuary and spit in Odisha. The novelty of this study is the need to understand the effects of natural disasters on the marine environment and wildlife. This study provides new and valuable data on the effects of specific cyclones on sea turtle populations and highlights the need for increased attention and protection of these important habitats. The period of shoreline change analyzed in this study was before (May 2, 2022) and after (May 17, 2022) the impact of cyclone Asani. Multi-temporal Sentinel 2A images and Digital Shoreline Analysis System were used to perform such an analysis. Field surveys were conducted using a Leica DGPS ArcPad, and group discussions with relevant stakeholders such as the fishing community, government officials, and coastal conservation guards were also undertaken. The findings of this study showed that the cyclone had a significant impact on the spit, dividing it into four smaller pieces and opening three new mouths. The spit experienced erosion and a significant reduction in length, and local fishing community reported that 15–20% of sea turtle eggs were washed away. This study highlights the severe threat to the survival of Olive Ridley sea turtles in Odisha due to changing cyclone patterns and the potential for degradation of the local ecosystem. The results of this study can aid in coastal conservation and management strategies to protect marine turtle populations in the region.

Extreme conditions reduce hatching success of green turtles (Chelonia mydas L.) at Karan Island, the major nesting site in the Arabian Gulf

Survival in the early life stages is a major factor determining the growth and stability of wildlife populations. For sea turtles, nest location must provide favorable conditions to support embryonic development. Hatching success and incubation environment of green turtle eggs were examined in July 2019 at Karan Island, a major nesting site for the species in the Arabian Gulf. Mean hatching success averaged at 38.8 % (range = 2.5–75.0 %, n = 14). Eggs that suffered early embryonic death (EED) and late embryonic death (LED) represented 19.8 % (range: 3.3–64.2 %) and 41.4 % (range: 4.8–92.6 %) of the clutch on average, respectively. Nest sand was either coarse (0.5–1 mm: mean 44.8 %, range = 30.4–56.9 % by dry weight, n = 14) or medium (0.25–0.5 mm: mean 33.6 %, range = 12.0–45.5 % by dry weight, n = 14). Mean sand moisture (4.0 %, range = 3.2–4.9 %, n = 14) was at the lower margin for successful development. Hatching success was significantly higher in clutches with sand salinity <1500 EC.uS/cm (n = 5) than those above 2500 EC.uS/cm (n = 5). Mean clutch temperatures at 1200 h increased by an average of 5.4 °C during the 50-d post-oviposition from 31.2 °C to 36.6 °C. Embryos experienced lethally high temperatures in addition to impacts of other environmental factors (salinity, moisture, sand grain size), which was related to reduced hatching success. Conservation initiatives must consider the synergistic influence of the above parameters in formulating strategies to improve the overall resilience of the green turtle population in the Arabian Gulf to anthropogenic and climate change-related stressors.

Trace Elements and Persistent Organic Pollutants in Unhatched Loggerhead Turtle Eggs from an Emerging Nesting Site along the Southwestern Coasts of Italy, Western Mediterranean Sea

Marine pollution is one of the major threats affecting loggerhead turtles, which due to their long life span, highly migratory behavior, and carnivorous diet, may be exposed to elevated levels of toxic elements throughout their life. The transfer of chemicals from mothers to their offspring is of particular conservation concern because it may affect embryonic development and hatching success. In this study, the concentrations of 16 toxic and potentially toxic trace elements, 6 indicator polychlorinated biphenyls (PCBs), and organochlorine pesticide residues (OCPs) were determined in 138 eggs from 46 loggerhead turtle nests laid during the 2021 nesting season in Campania, Italy, western Mediterranean Sea. The possible impact of pollutant levels on hatching success and early embryonic death was also investigated. Trace element analysis was performed using an ICP-MS, except for mercury, which was determined using a Direct Mercury Analyzer® (DMA). PCBs and OCPs were analyzed with high-resolution gas chromatography coupled with high-resolution mass spectrometry (HRGC-HRMS) and gas chromatography tandem quadrupole mass spectrometry GC-MS /MS, respectively. The concentrations of essential elements in the eggs were higher than those of non-essential elements. In addition, the highly chlorinated PCBs (153, 138, and 180) contributed the most to the total PCBs, while OCPs were not detected. No correlations were found between contaminant concentrations and reproductive parameters (hatching success and no obvious embryos). The results obtained suggest that the levels of contaminants found in the eggs do not affect the reproductive success of the species in the study area.

Thermal Response of Circulating Estrogens in an Emydid Turtle, Chrysemys picta, and the Challenges of Climate Change

Maternal hormones such as estrogens deposited into the yolk of turtle eggs follow circulating levels in adult females, and they may alter the sexual fate of developing embryos in species with temperature-dependent sex determination (TSD). In temperate regions, this deposition occurs during the spring when estrogens increase in adult females as ambient temperatures rise, drop after the first clutch, and peak again (albeit less) in the fall. Global warming alters turtle nesting phenology (inducing earlier nesting), but whether it affects circulating hormones remains unknown, hindering our understanding of all potential challenges posed by climate change and the adaptive potential (or lack thereof) of turtle populations. Here, we addressed this question in painted turtles (Chrysemys picta) by quantifying estradiol, estrone, and testosterone via mass spectrometry in the blood of wild adult females exposed to 26 °C and 21 °C in captivity between mid-August and mid-October (15 females per treatment). Results from ANOVA and pairwise comparisons revealed no differences between treatments in circulating hormones measured at days 0, 2, 7, 14, 28, and 56 of the experiment. Further research is warranted (during the spring, using additional temperatures) before concluding that females are truly buffered against the indirect risk of climate change via maternal hormone allocation.

European Pond Turtle (Emys orbicularis) Nest Predation: A Study with Artificial Nests

Nest predation significantly impacts the population decline of the long-living European pond turtle (Emys orbicularis). Kis-Balaton is one of the most important habitats of this species in Hungary, and in May 2017 more than 400 damaged nests were counted. To reveal predation pressure, we conducted a study with artificial nests on three sites in this area. On each site, we used 11 depredated real nests, and near each of them, we created new artificial nests; then in every nest we put one quail egg, one plasticine egg and several turtle egg shells. After that, we sprayed the smoothed surface of the covered holes with water-diluted turtle urine, imitating the turtle's behaviour. Already in the first three nights, 94% of all nests were depredated by the red fox (Vulpes vulpes) and in one case by the European badger (Meles meles), which was confirmed by the bite marks preserved on the plasticine eggs, by the footprints and excrements found near the nests, as well as by camera recordings. Only 6% of the nests survived during the three weeks of our study. Daily survival rates of quail eggs in artificial nests established in both real (damaged) and in new nests were similar, suggesting that estimates obtained with artificial nests reflect the degree of predation pressure on real nests. On the site where the nests were scattered, their daily survival rate (33%) was significantly lower than on the sites where their arrangement was partly scattered, partly linear (83%), or only linear (76%). On two additional sites, by using simulated turtle nests we showed that spraying the nests with diluted turtle urine and marking them with a flag did not affect their survival, although further methodological testing is needed. The information obtained with artificial nests enables the organization of the protection of the nests of the European pond turtle and selective predator control.

Environmental and pathological factors affecting the hatching success of the two northernmost loggerhead sea turtle (Caretta caretta) nests

In recent years, the report of loggerhead sea turtle (Caretta caretta) Mediterranean nesting range has expanded together with new records of nests becoming northward on the Italian coastline of the Tyrrhenian and Adriatic seas. These areas are characterized by intensive human activities, such as tourism, fishery, and marine traffic, all possibly involved in the influence of the use of coastal habitat by marine species. These anthropic threats, in addition to the natural ones and the changing environmental characteristics of the beach, may influence the growth of microorganisms causing hatching failures. Among microorganisms, fungal infection by the genus Fusarium (Link, 1809) is considered one of the main causes of globally declining sea turtle populations. In summer 2021, the two northernmost worldwide loggerhead sea turtle nests were monitored along the Northern Adriatic coastline (Veneto, Italy). These first records may potentially candidate this area as suitable for a large part of the loggerhead turtle’s life cycle and it could represent a minor sea turtle nesting area that, according to Prato and colleagues, remained unnoticed due to the lack of specific monitoring. Sea Turtle Egg Fusariosis (STEF) was deemed to have deeply compromised the hatching success of the northmost one. Climate change and anthropogenic impacts have been scored as one of the highest hazards to sea turtle health and could have played a role in the STEF development. Environmental changes, human activities, and emerging pathogens deserve the highest attention in terms of health research, and conservation management.

Validating trends in olive ridley sea turtle nesting track counts in Guatemala in light of a national hatchery protection strategy

AbstractThe olive ridley sea turtle Lepidochelys olivacea is the most abundant marine turtle species in Guatemala, representing &gt; 99% of all nests. Along with other marine turtles, they are important both culturally and ecologically. Conservation efforts rely almost exclusively on an informal system whereby local residents can harvest olive ridley sea turtle nests on the condition they donate 20% of each nest to a hatchery, where the eggs are incubated and hatchlings later released. This system was initiated in the 1970s and, until recently, no effort has been made to determine its sustainability. In a 2020 publication based on tracks on a single beach in Guatemala and 15 years of egg incubation data from Guatemalan hatcheries, it was concluded that the population had increased. Several weaknesses were detected in this research. To verify the validity of the conclusion, we analysed data from 22 years (2 years are missing) and 11 beaches using several statistical models. We used an intraseasonal model of nesting phenology to fill in missing data for monitored periods during a nesting season, and a new method of spatial and temporal aggregation of nesting seasons. Based on our findings, we reject the hypothesis that olive ridley sea turtle nesting activity is increasing. The total nesting activity for these 12 beaches was stable over the 22-year period. Because of inconsistent hatchery management and the financial dependency of local communities on the sale of turtle eggs, the number of incubated eggs cannot be used as an indicator of the population trend of olive ridley sea turtles in Guatemala.

Bacterial diversity of loggerhead and green turtle eggs from two major nesting beaches from the Turkish coast of the Mediterranean.

This study was conducted during the 2018 nesting season at the Sugözü Beaches (Adana-Turkey) and Göksu Delta (Mersin-Turkey). Egg samples (n = 63) from loggerhead and green turtle nests (n = 43) were collected. Isolated bacteria were initially identified by phenotypic methods and then by MALDI-TOF MS. The bacterial mass spectra were analyzed using Principal Component Analysis. Bacterial isolation was performed for 55 isolates belonging to 12 genera from two major nesting sites. In Sugözü Beaches 62.2% of the bacteria species belonged to Enterobacteriaceae and in Göksu Delta 44.4% of the bacteria species belonged to Morganellaceae. Klebsiella oxytoca and Staphylococcus haemolyticus had not previously been detected in any sea turtle nests. This is the first MALDI-TOF MS study conducted for determination of bacterial variability in loggerhead turtle eggs in Turkey and serves as a reference study for the assessment of bacterial threat in sea turtle nests, enabling the establishment of suitable conservation measures and treatment processes for both sea turtles and nesting sites.

Turtle eggs from the Lower Cretaceous Hasandong Formation (South Korea) with relict aragonite under significant thermal maturity

ABSTRACT Unlike the eggshells of other amniotes, turtle eggshells are composed of aragonite, which is a metastable mineral. Turtle eggshells in the fossil record are therefore usually transformed to calcite. Geothermal heat also negatively affects the preservation of aragonite, and therefore the preservation of aragonite under geothermal settings is not usually expected. Here we report new turtle eggs from the Lower Cretaceous (Aptian–Albian) Hasandong Formation of South Korea, describing the morphological features of the eggs and eggshells. The eggs belong to an oogenus Testudoolithus with the smallest recorded egg size. As one of the oldest fossil eggs from Korea, this material fills a paleobiogeographic gap in the fossil record of turtle eggs in East Asia, which has limited records for the eggs of non-dinosaurian reptiles. More importantly, the presence of relict aragonite was cross-validated by electron backscatter diffraction and Raman spectroscopy. The Raman spectra of the thermally altered organic matter inside the eggshells indicated that the eggs experienced a maximum temperature of almost 260°C during their taphonomic history. This implies that aragonite can be preserved even under hostile thermal conditions and earlier reports of ‘calcite-only’ turtle fossil eggs may preserve undetected relict aragonite, which is only detectable via careful investigation using advanced microscopic techniques. The combined use of mineralogical and spectroscopic approaches adopted in this study may also be useful to invertebrate paleontology and archeology to further understand the relationship between the preservation of aragonite and the maximum paleotemperature that the materials experienced.

Nutritional compositions, pathogenic microorganisms and heavy metal concentration in green turtle eggs (Chelonia mydas) from Terengganu and Sabah, Malaysia

A total of 60 green turtle eggs were obtained from sampling sites in Terengganu and Sabah, Malaysia. Isolation and identification of bacteria from these eggs resulted in 12 genera of Gram-negative bacteria with 12 different species. The most frequently isolated bacteria wereSalmonella(30.9%) andProteus(23.7%). The rest of the microorganisms wereAeromonas, Escherichia, Citrobacter, Enterobacter, Klebsiella, Morganella, Pseudomonas, Shigella, SerratiaandPhotobacterium.A slight difference in total crude protein content was recorded in the samples from Terengganu and Sabah, at 16.3% Dry matter (DM) and 15.8% DM, respectively. Meanwhile, the crude fat content found in the samples from Terengganu was 9.88% DM and 7.79% DM from Sabah. In this study, α-linolenic acid, C18:3 n-3 (Terengganu: 16.87% DM) and linoleic acid, C18:2 n-6 (Sabah: 15.19% DM) were the most prevalent fatty acids in both samples. The green turtle egg samples from Terengganu showed higher value of total saturated fatty acid, total C18:3 n-3 and C18:2 n-6 and total polyunsaturated fatty acids as compared to green turtle eggs from Sabah. The results also revealed that majority of the essential amino acids (EAA) recorded in samples from both sampling sites was lysine (9.67% DM), with higher value recorded in green turtle egg from Terengganu. However, there were no significant differences (p&amp;gt;0.05) in the nutritional compositions, fatty acid contents and amino acid compositions of the samples between the two sampling sites. Meanwhile, statistical analysis showed significant differences in heavy metal concentrations between the two sampling sites for all the six heavy metals detected in this study (Hg, Cd, Pb, Mn, Zn and Cu). The ranking of heavy metals concentration in turtle eggs from both sampling sites, in decreasing order is as follows: Zn &amp;gt; Cu &amp;gt; Mn &amp;gt; Pb &amp;gt; Cd &amp;gt; Hg. Overall, these results reveal the contents and contaminations of a green turtle egg, which may raise concern on public health risks. Findings from this study will also be beneficial for the future conservation of green turtle population when the consumption of their eggs should be stopped.

Inhibition mechanism of oligopeptides from soft-shelled turtle egg against α-glucosidase and their gastrointestinal digestive properties.

Peptides derived from egg protein hydrolysate have potential hypoglycemic benefits by inhibiting α-glucosidase. Herein, fluorescence spectroscopy and molecular docking were performed to investigate the α-glucosidase inhibitory mechanism of the oligopeptides ARDASVLK and HNKPEVEVR from soft-shelled turtle eggs. Gastrointestinal digestion characteristics of the two oligopeptides were further determined by LC-QTOF-MS/MS. The static fluorescence quenching of α-glucosidase by ARDASVLK and HNKPEVEVR indicated the formation of a stable α-glucosidase-peptide complex, mainly driven by hydrogen bonds and hydrophobic interactions. ARDASVLK and HNKPEVEVR could easily insert into the active pocket of α-glucosidase (docking scores of -157.1 and -158.4, respectively), thereby inhibiting enzyme activity by preventing substrate binding and inducing enzymatic conformation change. After gastrointestinal digestion, 14.3% and 30.4% of ARDASVLK and HNKPEVEVR were maintained intact, respectively, and their digestive products (mainly DASVLK and HNKPEVEV) still showed high inhibitory effects on α-glucosidase (about 35% inhibition). This study sheds light on the mechanism of oligopeptides derived from soft-shelled turtle eggs as a novel α-glucosidase inhibitor for diabetes. PRACTICAL APPLICATIONS: Oligopeptides from egg protein hydrolysate have potential hypoglycemic properties by inhibiting α-glucosidase. This study has provided insights into the inhibitory mechanism of oligopeptides from soft-shelled turtle egg on α-glucosidase. Interestingly, despite the fact that the oligopeptides are largely degraded during gastrointestinal digestion, their digestive metabolites displayed strong α-glucosidase inhibitory activities. Because α-glucosidase is highly expressed in small intestine brush border, our findings support the possibility of these oligopeptides as an attractive health-benefit compound to control glucose without being absorbed by intestinal epithelial cells, unlike other enzyme inhibitors such as ACE inhibitors, which have poor oral bioavailability. This study may facilitate the applications of oligopeptides from soft-shelled turtle egg as α-glucosidase inhibitors and food functional ingredients for the therapy of diabetes.