Hatchling Success Research Articles

Nesting Ecology of Lepidochelys olivacea in Lobito, Angola.

The scarcity on the Atlantic coast of the African sea turtle population and its dynamics data is well known. This article discusses the nesting ecology methods and analysis of a nascent Angolan project aimed at preserving the nesting female population of the Olive Ridley turtle (Lepidochelys olivacea) on the coast of Lobito. This study examines the nesting ecology of this species from 2020 to 2023. Females had an average CCL of 70.2 cm and CCW of 68.5 cm. These females laid 127 eggs in nests that averaged 47.0 cm deep. The ex situ nest incubation period averaged 60 days, and the hatchling success was 82.1%. Some techniques used in this project require modifications and enhancements. The utilization of photo identification did not yield the anticipated outcomes, prompting the adoption of passive integrated transponders (PITs) in the last season. However, due to limited funding, the success of this method is contingent upon an augmented field effort, allowing for the recapture of a larger number of females. The continuity of this project hinges upon collaboration between higher authorities and the local community. Together, it is possible to deepen the understanding of the nesting ecology of this species and address pivotal issues for its conservation, thereby implementing the most effective preservation measures.

Environmental and Nesting Variables Associated with Atlantic Leatherback Sea Turtle (Dermochelys coriacea) Embryonic and Hatching Success Rates in Grenada, West Indies

Annual monitoring of leatherback sea turtle (Dermochelys coriacea) nesting grounds in Grenada, West Indies has identified relatively low hatch rates compared to worldwide trends. This study investigated the impact of selected environmental variables on leatherback sea turtle embryonic development and hatching success rates on Levera Beach in Grenada between 2015-2019. The mean number of nests per year and eggs per nest were 667.6 ± 361.6 and 80.7 ± 23.0 sd, respectively. Within excavated nests, 35.6% ± 22.0 sd of eggs successfully developed embryos and 30.6% ± 22.6 sd of eggs successfully hatched. The number of eggs per nest, along with embryo and hatching success rates, differed by nesting year. Embryo development success rate was associated with nest location, and both embryo development and hatching success rates were positively associated with nest depth and negatively associated with the percentage of eggs exhibiting microbial growth and with the presence of inspissated yolk. There was no embryo development or hatchling success association with month of the nesting season, distance from the high-water mark, distance from vegetation, nor maternal carapace length. The mean nest temperature was 31.7 °C ± 1.64 sd and mean temperatures during the middle third of egg incubation suggest clutches are highly skewed towards a preponderance of female hatchlings. Histopathologic findings in hatchling mortalities included severe, acute, multifocal, heterophilic bronchopneumonia with intralesional bacteria in 4/50 (8%) hatchlings. Data from this study guide conservation strategies by identifying risk factors and further avenues of research needed to support reproductive success of leatherback sea turtles in Grenada and the greater Caribbean region.

Neglecting cooler low-season nest protection could deprive sea turtle populations of valuable hatchlings

Reproductive seasonality is present across species and phyla. Many species retain seasonal patterns even in tropical regions where climatic variations may be less apparent. Environmental features and large-scale environmental cues play a role in species seasonality and can have major effects on reproductive success. In organisms that present environmental sex determination, the season in which individuals reproduce has consequences for their primary sex ratio. Here we looked at the possible effects on fitness and primary sex ratio for the olive ridley sea turtle (Lepidochelys olivacea) when nesting during peak and low nesting seasons. In the eastern Pacific, peak olive ridley sea turtle nesting occurs during the warmest months, which coincide with the rainy season. Yet, as nesting takes place year-round, a small proportion of the nests laid during the dry part of the season are exposed to contrasting environmental conditions. Most of the studies on Pacific coast sea turtles have estimated sex ratios produced during the rainy, high abundance period when most conservation activities are focused. Thus, dry-low season nests have on the whole, been overlooked. Here we compared sex ratios and hatchling fitness for offspring produced during the dry and rainy seasons in 2015. We found that olive ridley clutches incubated during the dry-low season were exposed to lower temperatures, yielded higher hatchling success, mainly produced male offspring and larger, heavier hatchlings with better locomotor abilities. This highlights that, for sea turtles, protecting nests outside of the peak nesting season may help future population viability by yielding higher proportions of males with greater locomotor capacities and, thus, survival. Our results highlight the critical value of monitoring and protecting species during their entire reproductive period and not concentrating all resources on the peak season to collect more data and protect a greater number of organisms. Our results suggest that monitoring low-season reproductive effort (nests in this case), albeit at much lower densities, would be critical for understanding and possibly ensuring population viability and adaptation to contemporary climate change and anthropogenic threats.

First report on two loggerhead turtle (Caretta caretta) nests in the Aeolian Archipelago (Southern Italy)

The Aeolian Archipelago (Southern Tyrrhenian Sea, Italy) hosts important foraging/overwintering habitats for Mediterranean loggerhead sea turtles (Caretta caretta), although nesting sites have never been documented. This study reports the data of two nesting events occurred in summer 2019 at Stromboli and Lipari islands. A hatchling success of 20.69 % (18 hatchlings from 87 eggs) was recorded at Stromboli, while a complete hatchling unsuccess characterised the Lipari nest, where 111 eggs were deposited. Data acquired during the monitoring of the nests suggest that combined factors, mainly temperature, beach morphology, and sand composition, could be the causes for the low success of these nesting events.

Bioaccumulation and impact of maternal PFAS offloading on egg biochemistry from wild-caught freshwater turtles (Emydura macquarii macquarii)

Per- and polyfluoroalkyl substances (PFAS) are persistent synthetic contaminants that are pervasive in the environment. Toxicity resulting from elevated PFAS concentrations in wildlife has been studied, yet evidence of their accumulation, developmental toxicity and maternal offloading in egg-laying species is limited. Here we show the maternal offloading of PFAS in freshwater short-necked turtles (Emydura macquarii macquarii) exposed to elevated PFAS and the resulting biological impact on oviducal eggs. Total PFAS concentrations were determined in serum from adult females and harvested oviducal eggs collected from euthanised turtles exposed to low and high levels of PFAS and compared against turtle serum and eggs collected from a suitable reference site. Multi-omics assays were utilised to explore the biochemical impact of elevated PFAS on egg albumen, yolk and eggshell using a range of metabolomics, lipidomics, and proteomics techniques. Eggshells were also screened for metals by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Analysis of the serum collected from adult female turtles and their oviducal eggs demonstrated PFAS offloading and transference that is 1.6 and 5.3 times higher in the low and high PFAS impacted eggs, respectively, compared to maternal serum concentrations. Oviducal egg yolk comprised >90% of the bioaccumulated PFAS load. Multi-omic analysis of the dissected egg fractions illustrated PFAS impacted eggs are significantly elevated in purine metabolism metabolites, which are tied to potential biological dysfunctional processes. The yolks were significantly depleted in lipids and lipid quality tied to growth and development. The high PFAS impacted oviducal eggshells were lower in calcium, important developmental and immune response proteins, and higher in glycerophosphoethanolamines (PE) lipids and histidine metabolism metabolites that are tied to a weakened physical structure. Further investigation is needed to establish the rate of PFAS offloading and quantify the developmental impact on hatchling and hatchling success to fully demonstrate PFAS-developmental toxicity linkages.

Influence of temperature variation on incubation period, hatching success, sex ratio, and phenotypes in Caiman latirostris.

Temperature is crucial for reptiles, also during embryonic development,particularly for species with temperature-dependent sex determination. Under natural conditions, Broad-snouted caiman (Caiman latirostris) eggs are influenced by thermal changes in the interior of the nest related to the external environmental temperature. Asnests are subject to variations in temperature and most lab studies on crocodilianincubation have beencarried out at constant temperatures, we were interested in determining how temperature fluctuations may affect the development of caiman embryos. We investigated the effects of incubation at constant temperatures (31°C, 32°C, and 33°C) and fluctuating temperatures (31 ± 2, 32 ± 1, and 32 ± 2°C) on the following aspects: incubation period duration, hatching success, sex ratio, total length, and body mass of C. latirostris hatchlings. Eggs incubated at 31°C produced 100% females, those at 32°C produced 71.6% females (however, the sex ratio was nest related), and at 33°C produced 100% males. We found a masculinizing effect when incubation was at 31 ± 2°C compared with a constant 31°C; and temperature fluctuations at 32°C (32 ± 1 and 32 ± 2°C) had a negative effect on hatchlings size and mass, and hatching success compared with constant incubation temperatures of 32°C and 33°C. Finally, the effect of temperature variation during the incubation period on sex ratio, hatching success, and phenotype depends on the mean temperature, asthe fluctuation around 31°C affected the sex ratios and incubation period, and the fluctuation around 32°C affected hatchlingsuccess and size.

Effect of sand granulometry on the egg hatchling success of the sea turtle Caretta caretta

The environmental characteristics of nesting sites of sea turtles may directly interfere with the egg hatchling success. The objective of the present study was to evaluate the factors that affect the success of hatchling in the nests of the loggerhead sea turtle (Caretta caretta). Data from 37 nests of C. caretta from the coast of Mata de São João, Bahia, northeastern Brazil, were obtained from TAMAR, Sauípe station. Samples of sand were collected in each nest to determine the granulometry. A significant negative relationship was found between the stillborn rate and the fine sand ratio (r2 = 0.119; p = 0.036), indicating that a larger fraction of fine sand had a positive effect on nest hatchling success. The egg laying date also had a significant influence on the rate of stillbirths (r2 = 0.163; p = 0.013), with a trend towards a higher stillbirth rate, the later the laying date of the eggs. There is indication that the transfer of eggs to sites with more favorable characteristics may be considered as a potential alternative to increase the hatchling success rate of C. caretta eggs.

Low-quality dwarf-shrub litter negatively affects the fitness of Alpine earthworms (Lumbricus rubellus Hoffmeister, 1843; Oligochaeta: Lumbricidae)

Alpine pastureland is increasingly abandoned, leading to shrub encroachment and to the accumulation of low-quality litter. Alpine key decomposers such as earthworms were found to feed on both low- and high-quality litter, but little is known how this might affect their life history traits.To fill this gap of knowledge, we conducted a laboratory experiment with the widespread earthworm species Lumbricus rubellus Hoffmeister, 1843. Hatchlings were provided with either of three aged litter types: grass and forb leaf litter as high-quality food sources and dwarf shrub leaves as low-quality food source. A control group was fed with aged cow dung. Biomass, days until (pre-)maturity, mortality, and reproduction rate were measured regularly to assess the impacts of food quality on earthworm development.We found pronounced impacts of food source quality on the fitness of L. rubellus. The low-quality litter led to significantly delayed development of up to 53 days, the lowest mean biomass (720 mg after 32 weeks) as well as a 50% drop of produced cocoons compared with the high-quality litter. However, the F2 generation showed the highest hatchling success in the shrub treatment.We conclude that the increased consumption of low-quality dwarf shrub litter led to negative effects on the development and reproduction of L. rubellus. Overall, this might be the main reason for declining earthworm densities in abandoned Alpine pasture soils, even though the biomass of the second generation was not significantly affected possibly due to a phenotypic variability in reproduction strategy. However, the decrease of such important decomposers and ecosystem engineers can have far reaching consequences for ecosystem processes such as litter accumulation and bioturbation and thus for the stability of Alpine soil ecosystems.

Effectiveness of Concealed Nest Protection Screens Against Domestic Predators for Green (Chelonia mydas) and Hawksbill (Eretmochelys imbricata) Sea Turtles

Mammalian depredation of nests has been listed amongst the most significant threats to hatchling success in sea turtles. In 2013, at least 13% of green turtle (Chelonia mydas) and 25% of hawksbill turtle (Eretmochelys imbricata) nests were lost to domestic dog predation on Playa Norte, Costa Rica. In 2014 and 2015, plastic and bamboo protective screens were deployed to protect nests. Screens were deployed at different stages of the incubation period and the success of the nests analyzed. Predation rates increased as the seasons progressed with October and November being the peak depredation months, as well as the peak for hatchling emergences. Eggs remaining in nests that had been partially depredated had a significantly lower percentage of hatching success than eggs in undisturbed nests. There was no significant difference between timing of deployment and likelihood of a screen being breached. The likelihood of a screen being breached was highly dependent on the type of material used; bamboo screens were ca. 153% more effective than plastic and successfully prevented the complete predation of ca. 48% of nests. Bamboo screening is an inexpensive, environmentally inert, yet labor-intensive method for reducing nest depredation by domestic dogs. This screening method does not impact the hatching or emerging success of the nest.

Breeding rate and mortality in Australian parrot (Melopsittacus undulatus) in captivity at Bahawal Pur, Pakistan

The present study was conducted to find out the breeding rate and mortality of Melopsittacus undulatus (budgerigar), a famous species of Australian parrots. A total of 100 birds (50 pairs), kept in a farm house at Bahawal Pur, Pakistan were used in this study. Number of eggs, clutch size, number of hatchings, hatchlings and fledglings were recorded for estimation of breeding rate. Total number of eggs was 537 during whole breeding season. Clutch size varied from 1-9. The hatching and hatchling success was found to be 29.69% and 81.76% respectively. The clutch size and number of eggs laid in breeding season were adequate for rapid increase in population. The hatching rate and fledging rate indicated good reproductive success in captivity. Keywords: Budgerigar; Clutch size; Hatching success; Fledglings http://dx.doi.org/10.19045/bspab.2017.60051

Ecología de la anidación de Crocodylus acutus (Reptilia: Crocodylidae) en Bahía Portete, La Guajira, Colombia

C. acutus is cataloged in critical danger in Colombia. We studied its population at Bahia Portete, in order to survey the nesting activities and to obtain valuable information for a conservation management program. This study was undertaken with the participation of the Wayuü community using the Agreement Conservation Model, and took place during July 2007, August 2008, June and August 2009, and March to August 2010 and 2011. Sampling surveys were made by the use of transects along the coast, in order to find nests. For each nesting area found, we recorded the nests biometrics, eggs and hatchlings, fertility of the eggs and reproductive events. We explored a total of 55.12 km, and determined four nesting areas. Colonial nesting and the environmental variables were factors that affected the hatchling success. From the total of nests found, 37 % were oriented towards North, and 48 % were built next to Stenocereus griseus. Juyi island substrate was mostly constituted by sand (71.9 %, 71.44 %). The average number of eggs by nest was 28.42 ± 6.63, the largest egg diameter was 71.84 ± 3.54 mm, the average nest weight was 81.54 ± 9.99 g, and the hatchlings presented an average length of 25.47 ± 1.16 cm. For this specific site in Colombia, the reproductive period begins in March and ends in August. The few areas of nesting and the 95 % fertility suggest the performance of a conservation management program for this species at Bahía Portete.

Reptile embryos and climate change: Modelling limits of viability to inform translocation decisions

The embryos of many egg-laying species develop under the environmental conditions selected by one or both parents, and these conditions may cease to be optimal under a changed climate. Assisted colonization is an emerging option to relocate species that are threatened by unfavourable changes in the local climate, but the incubation requirements of embryos are rarely considered in conservation translocations despite suggestions that relocation of early life stages could be more effective than relocating older animals. Here we review examples and outcomes of relocations of reptile eggs, and the decision tools currently available for guiding translocation decisions from an embryonic perspective. We then demonstrate a mechanistic approach, using the modelling framework NicheMapR, for assessing the optimal translocation range for the Western Swamp Turtle (Pseudemydura umbrina), a Critically Endangered reptile with an extremely restricted natural distribution. We determine thermal reaction norms and critical thermal limits for embryonic development based on laboratory and field data, and model soil temperatures at typical nest depths, simulate embryonic development at these depths, and map the probability of survival of P. umbrina embryos within the major bioregions of south-western Australia. The same model forced by future climates for 2050–70 demonstrates a southerly shift in the regions where embryos would be viable. However, if P. umbrina is to be translocated in the near future to regions 300–400km south of its natural range, females will need to nest in relatively unshaded sites to achieve temperatures that are high enough to promote hatchling success.

Relationship between multiple paternity and reproductive parameters for Podocnemis sextuberculata (Testudines: Podocnemididae) in the Trombetas River, Brazil.

Genetic studies of multiple paternity are a valuable tool to gain information on the reproductive biology of turtles. We analyzed paternity type in Podocnemis sextuberculata and related number of fathers per nest to nesting period (beginning, middle, or end of nesting season); clutch size (number of eggs); female size; and hatchling success. Females were captured and maximum linear carapace lengths measured during the 60 days that encompass the nesting season at Rio Trombetas Biological Reserve (Pará, Brazil). Nests were marked and blood samples collected from hatchlings. Six heterologous loci were used: five from Podocnemis unifilis and one from Podocnemis expansa. Hatchlings were analyzed from 23 nests, and the rate of multiple paternity was 100%. The mean number of fathers per nest was six (± 0.9), and no significant difference between number of fathers in a nest and nesting period. Similarly there was no significant relationship between number of fathers in a nest and female size or hatchling success rate. Number of fathers was, however, positively correlated with clutch size (Spearman correlation rho = 0.47; P > 0.05). To our knowledge, this is the first study to test the relationship between multiple paternity and ecological aspects of the reproductive ecology of turtles in the genus Podocnemis.

Using a microclimate model to evaluate impacts of climate change on sea turtles

Sea turtles are thought to be particularly vulnerable to climate change as projected increases in temperature may skew the sex ratio of their hatchlings, decrease hatchling success and thus threaten population persistence. Given the seriousness of the threat from climate change it is critical to understand the rate at which soil temperatures at sea turtles’ nesting grounds are likely to change. This has stimulated the development of correlative models to assess and project how projected increases in temperature may impact sea turtle's reproductive output. Correlative models correlate climatic variables to soil temperature and hatchling sex ratio. These models have been widely used due to their simplicity and the flexibility of their data requirement. However, outputs are restricted by the environmental conditions used for the model and thus does not allow exploration of daily variation in sand temperature. Further, the potential error inherent in this approach has not been determined.Researchers working with other animals with temperature-dependent sex determination (TDS) have developed microclimate models to determine nest temperature and potential impacts from climate change. Microclimate models use the interaction between climate, soil, and topography with physiology and nesting behavior of animals to determine future production of hatchling sex ratios. Until now, microclimate models have never been applied to sea turtles and its correlation and consistency with correlative models has never been explored. To address this, we used the Niche Mapper™ microclimate model to project soil temperature at key sea turtle nesting grounds under various scenarios of global warming. Results from the microclimate model are compared to published projections from correlative models. The two approaches accurately and congruently model current soil temperature and project a feminization of the northern Great Barrier Reef green turtle population as climate change progresses. To provide guidance of when to use each approach we also reviewed the applicability and effectiveness of each model. The microclimate model provided a more robust picture of the incubating environment as it has the potential for projecting soil temperature for every hour of the day at various locations and depths within a nesting ground. This allows exploration of whether animals with TDS can counteract the impacts of global warming by changing nest depth and nesting distribution. With time and the validation of the microclimate model with short-term projections, the microclimate model can also be used to refine short-term adaptive management strategies as they can provide explicit recommendations on site-specific scales for translocation of eggs and alteration of the nesting environment.

The Flame Retardant β-1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane: Fate, Fertility, and Reproductive Success in American Kestrels (Falco sparverius)

Captive American kestrels (Falco sparverius) were exposed via diet during reproduction to an environmentally relevant concentration of β-1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (β-TBECH). The β-TBECH isomer was injected into the food source at a daily dosing concentration of 0.239 ng/g kestrel/day (22 pairs); control birds were exposed via diet to the safflower oil vehicle only (24 pairs). Eight pairs in each group were exposed for four weeks and sacrificed for tissue analysis; the remaining pairs completed their breeding cycle, with exposure ceasing at the end of incubation (82 days). α- and β-TBECH appeared to be rapidly metabolized and/or eliminated from fat, liver, and plasma; both isomers and potential hydroxylated metabolites of β-TBECH (plasma) were undetected. Notwithstanding, compared to controls, pairs exposed to β-TBECH laid fewer eggs (p = 0.019) and laid lighter eggs (successful eggs: p = 0.009). Exposed pairs also demonstrated poorer egg fertility (p = 0.035) although testis mass and histology were similar among males. Reductions in egg production and fertility resulted in decreased hatchling success (p = 0.023). The β-TBECH-exposed pairs also produced fewer males overall (p = 0.009), which occurred concurrently with increased estradiols maternally deposited in eggs (p = 0.039). These findings demonstrate that β-TBECH may be detrimental for breeding in wild birds receiving similar exposure levels.

Dispatches

Dispatches

Patterns of maternal investment in spotted turtles (Clemmys guttata): Implications of trade-offs, scales of analyses, and incubation substrates

To maximize potential fitness, reproductive females should invest available resources in either larger propagules (egg and/or hatchling size) or more propagules (clutch size). Females may also enhance offspring performance by selecting nest sites with optimal conditions for the developing eggs. This study examined maternal investment in a population of spotted turtles (Clemmys guttata) in Ontario, Canada over 2 y using radio telemetry, x-ray photography, and indirect assessments of hatchling fitness. Analyses were conducted at 2 scales (clutch and female), utilizing 2 measures of available resources (body size and body condition). Larger females produced wider eggs, and similarity in the slopes of egg width and maternal pelvic aperture on body size may indicate a physical constraint on egg size. However, body size did not explain variation in egg morphometrics (length, width, or mass) when considering the reproductive output of each female over the entire study. Instead, females in better body condition produced more eggs. With respect to nest site selection, no selection for thermal properties was observed, and females exhibited stronger fidelity to nest substrates than to nest locations. Hatchling righting response was not related to hatchling body size or condition, but hatchlings from a clutch performed similarly, indicating maternal genetic effects or an effect of nest conditions. Thus, females in good condition maximize the number of eggs produced over multiple years, and hatchling morphometrics may not directly influence hatchling success.

Growth and fecundity of earthworms: Perionyx excavatus and Perionyx sansibaricus in cattle waste solids

Epigeic earthworms (Oligochaeta) have been appeared as key organisms to convert organic waste resources into value-added products, i.e., vermicompost and worm biomass. The assessment of reproduction potential of composting earthworm may be beneficial for large-scale earthworm production. Although, the waste minimizing potential of Perionyx excavatus and Perionyx sansibaricus is well proved, but little information is available about their fecundity rate. In this study, the efforts have been made to explore the growth and reproduction biology of P. excavatus and P. sansibaricus, using cattle waste solid as culture substrate, under laboratory conditions. Earthworms were weighed weekly and number of cocoons produced per week assessed. Biomass productions, fecundity, maturation, natality all were significantly different between P. excavatus and P. sansibaricus. The highest mean individual biomass was 767.7 ± 18.4 mg and 612.6 ± 20.6 mg, respectively in P. sansibaricus and P. excavatus. However, the highest cocoon numbers occurred in P. excavatus (492.3 ± 13.6), significantly higher than P. sansibaricus (269.6 ± 17.1). Fecundity was slightly different in both species: 1.38 ± 0.77 cocoons adult worm−1 week−1 (P. excavatus) and 1.58 ± 0.74 cocoons adult worm−1 week−1 (P. sansibaricus). The hatchling success rate (%) was highest in P. excavatus. Overall natality (juveniles adult−1 week−1) was highest in P. sansibaricus (1.52) than P. excavatus (1.26), which suggests that P. sansibaricus may be a better candidate for rapid propagation of earthworms in cattle waste solid.

Does substrate quality affect earthworm growth and reproduction patterns in vermicomposting systems? A study using three popular composting earthworms

Efforts were made to evaluate the impact of substrate materials (crop residues + sheep manure, cowshed manure, and kitchen waste + leaf litter) on growth and reproduction performance of composting earthworms: Eudrilus eugeniae, Perionyx excavatus and Perionyx sansibaricus, under laboratory conditions. Results indicated that earthworm biomass and cocoon production rate was directly related to the type of earthworm species as well as nature of worm feedstuff. Although cocoon hatchling success did not show any relation with type of culture material, but hatchlings numbers cocoon−1 was directly related with quality of substrate. This study suggests that earthworm production can be managed by using feedstuff having higher nitrogen contents with low C:N ratios.

INFLUENCE OF DIFFERENT FOOD SOURCES ON GROWTH AND REPRODUCTION PERFORMANCE OF COMPOSTING EPIGEICS: EUDRILUS EUGENIAE, PERIONYX EXCAVATUS AND PERIONYX SANSIBARICUS

The impact of organic material quality on biomass production and reproduction potential of commercial composting earthworm species: Eudrilus eugeniae, Perionyx excavatus and Perionyx sansibaricus were studied, by using three different type of culture material namely Jbs: (Jowar straw (Sorghum vulgare ) + bajra straw ( Pennisetum typhoides ) + sheep manure) (1:1:2), fym (farmyard manure), and Kw + Ll (Kitchen waste + leaf litter of Magifera indica ) (1:1), under laboratory conditions for 150 days. The above substrate or culture materials have different palatability, particle size and physio- chemical composition. Kitchen waste (C-to-N = 26.7) as well as farmyard manure (C-to-N = 27.4) is a high quality material with fast decomposition rates, while crop residues are low quality materials with slow decomposition rates (C-to-N = 45.6). All the three studied earthworm species showed maximum biomass production rate in Kw + Ll culture ( E. eugeniae = 9.80 ± 0.01 mg worm -1 day -1 , P. excavatus = 3.75 ± 0.01 mg worm -1 day -1 , and P. sansibaricus = 3.77 mg worm -1 day -1 ). Individual cocoon production rate varied drastically, and maximum value (worm -1 week -1 ) of it was observed in Kw + Ll for E. eugeniae (1.88 ± 0.15) and P. sansibaricus (1.77 ± 0.14), while P. excavatus showed maximum cocoon production rate in Fym (1.79 ± 0.17). The hatchling success of cocoons obtained from different beddings was also observed and cocoon obtained from Kw + Ll culture exhibited maximum hatchling success (%) in all the three species studied. The cocoons of both E. eugeniae and P. sansibaricus , obtained from Fym culture showed the highest number of hatchlings (cocoon -1 ) i.e. 1.59 ± 0.04 and 1.81 ± 0.10, respectively, whereas cocoons of P. excavatus showed the highest hatchling number (1.77 ± 0.06) in Kw + Ll. In this present study, there was a consistent trend of decreasing individual biomass as well as cocoon production rate, followed by their peak values with ageing of the culture materials. The relationship between different earthworm parameters and N-content or C-to-N of culture material was also evaluated. The biomass production rate and hatching success in all the three species studied showed direct correlation (p<0.05) with N-content of the culture material. However, beddings' N-content did not affect the individual cocoon production rate, except to P. sansibaricus (r = 0.987, P<0.001). The number of hatchlings per cocoon for P. sansibaricus, showed good correlation (r = 0.935 p<0.01) with N-content of organic material used for worm culture. Results clearly show a possible relation between hatchling success/number of hatchlings per cocoon, and chemistry of culture substrate.