Oology Research Articles

Implementing a fishery improvement programme to manage the common cuttlefish (Sepia officinalis) in artisanal sea and lagoon fisheries: The case study of the Chioggia’s fleet

In the light of reducing the impact of fishery, artisanal fisheries hold great potential to achieve the sustainable use of marine resources if locally managed at sub-regional level (i.e., within the same province or fleet) and by implementing mitigation systems. The Chioggia small-scale fishing fleet represents a study case in an overexploited Mediterranean sub-region, operating both in the Venice Lagoon and the North Adriatic Sea. During the spawning period, this small-scale fishery targets the same target species, the common cuttlefish (Sepia officinalis), which, over the past thirty years, has shown a general decline in catch trends. Cuttlefish represent a high-value resource at all life stages, with both adults and juveniles considered targets of the artisanal fishery. Additionally, eggs are consistently laid on fishing gear during the breeding season and must be removed by fishers to prevent a reduction in fishing efficiency. These aspects contribute to the vulnerability of the common cuttlefish stocks, calling for a complementary management approach. We researched methods from the peer-reviewed literature, and adapted methods to reflect the environmental conditions of the sea and lagoon, and small-scale fishing methods. We combined into a complementary management approach: i) mitigation systems to reduce and collect eggs discarded during fishing operations, ii) semi-natural juvenile rearing diets to potentially release fishing pressure and support natural population, and iii) small-scale supply chain to both raise awareness about this resource vulnerability and promote the activity of fishers adopting virtuous behaviours. We tested these three functional management units in collaboration with lagoon and sea fishers and local stakeholders. We showed that the use of egg collectors, as an alternative spawning structure, performed well to limit the loss of the eggs laid upon the fishing gears. Second, we showed that Mixed and Natural diets contributed significantly to the growth rate of hatchlings compared to artificial diets. Finally, we demonstrated a shared interest in products derived from sustainable fisheries from the public, fishers and retailers. Therefore, the small-scale supply chain can represent a valid component to valorise the adoption of the whole management scheme. Overall, this complementary management approach can be adapted to and implemented in other local socio-economic communities of artisanal fishing in coastal environments worldwide. Complementary mitigation systems could work in synergy, overcoming the limitations of individual mitigation measures applied to diverse fishery resources.

Olive Ridley Sea Turtle Incubation in Natural Conditions Is Possible on Guatemalan Beaches

The Guatemalan strategy for sea turtle conservation was defined by the National Council of Protected Areas (CONAP) in 1989. Hatcheries lie at the core of this strategy: egg collectors are allowed to deliver 20% of a nest to a hatchery in exchange for selling or eating the remaining eggs. Consequently, nearly 100% of nests are collected, with no nests being left on the beaches. Hatchery design promotes shading using roofs made from vegetation. The logic behind this recommendation is that the natural incubation of eggs is supposedly impossible due to the overly high temperatures on the beach. However, changing the incubation temperature of sea turtle eggs can profoundly alter the sex ratio in sea turtles with temperature-dependent sex determination. It can also modify the physiology or behavior of juvenile turtles. Here, we test whether incubation in natural conditions is possible on Guatemalan beaches, and for the first time, we determine the thermal reaction norm of embryo growth to ensure hatching success in sea turtles. We show that incubation in natural conditions is possible since three out of the four monitored nests produced hatchlings. We urge the Guatemala National Council of Protected Areas to reevaluate its strategy for sea turtle conservation in Guatemala in light of these results.

Changing Economic Strategies in the Ecsed Marsh

The Ecsed Swamp was formed in the New Holocene Era in the lowest areas of Nyírség and Szatmár Plains. Besides the protective nature of the swamp, it was a significant source of livelihood for the local population – loach fish collecting (csikász), bird hunting and egg collecting (pákász) were the main occupations of the “swamp people”. The Ecsed Swamp, which once covered almost 432 km2 was drained at the end of the 19th century that caused significant changes in everyday life and farming. The inhabitants of the so-called “Loach land” (Csíkország) tried to dig up and cultivate marshy areas even before the drainage. Burning, cutting and cleaning were already known among the swamp people, since this was the only way to carry out farming activities in this area. In their frustration the swamp people effected by the drainage tried to obtain land for cultivation. They worked on the lands purchased by the Károlyi noble family. More prosperous ones also built farms on the border of the neighbouring villages, thus the process of homesteading began. In the 21st century, the cultivation of agricultural land in the area of former swamps is causing significant problems since water shortage is now characteristic towhole Europe. Reedfires in the former swamp areais a phenomenon that exists to this day. With the transformation of landscape and ways of farming and living, the need to apply different economic strategies arose, which I will discuss t in my research study with case studies from the 19th and 21st centuries.

Oological collections and egg collectors of Brazilian birds: an overview

Egg collections have been poorly studied and cataloged both in Brazil and overseas. In Brazil, there is a lack of both historical and current tradition of establishing and curating egg collections. This paper provides information about the size of collections, collecting dates, major collectors, geographic locations, and institutions holding egg sets of Brazilian birds. Through this effort, we recovered part of the history of Brazilian ornithology and provide general directions for those interested in studying egg sets deposited in scientific collections. We retrieved information from 5,888 egg sets collected in Brazil between 1818-2022, currently deposited at 45 institutions/museums. The four largest egg collections in Brazil are at MZUSP, MN, COMB and MPEG. However, around half of the egg sets are deposited in institutions from Europe (mainly at MLUH and ZMB in Germany, NMW in Austria, NHM in the UK, and CRRM in Romania) and the USA (mainly at the WFVZ). Most egg sets were collected between the 1890s and 1930s, and after 2010. In Brazil, 70% of the egg sets were collected in five Brazilian states (MG, SP, SC, PA, and RS). Overall, egg collecting was uneven in space and time. We traced ~330 egg collectors, but most egg sets were collected by José Caetano Guimarães Sobrinho, while Caio Guimarães Chagas was probably the greatest collection owner in Brazil. A recent increase in egg collecting shows a renewed interest in assembling this type of bird vouchers. A scientifically sustained, planned and ethical collection of eggs should continue in Brazil since the breeding biology of many species is still poorly known, and since egg sets are important to provide data for new studies on the ecology, evolution, and conservation of Brazilian birds.

Sparicotyle chrysophrii experimental infection of gilthead seabream (Sparus aurata): Establishment of an in vivo model reproducing the pathological outcomes of sparicotylosis

Sparicotyle chrysophrii (Microcotylidae) is considered the most threatening pathogen affecting the gilthead seabream (GSB; Sparus aurata) off-shore farming due to its economic impact. This study explores the best experimental conditions to set up an in vivo infection model capable of mimicking the sparicotylosis signs observed in farmed diseased fish. The experimental setup for parasite transmission consisted of a recipient (R) fish tank with naïve GSB receiving water from two S. chrysophrii-infected donor tanks in a recirculating aquaculture system (RAS). Egg collectors, consisting of a polyester mesh in a supporting plastic frame, were placed in the R tank in order to monitor the progression of the parasitosis. An additional tank with control unexposed naïve fish was maintained in parallel, with open water flow and disconnected from the RAS. After a preliminary trial, infective pressure in the R tank was increased by placing an additional egg collector already loaded with entangled parasite eggs, and by maintaining the fish number throughout the experiment.Adult S. chrysophrii parasite load correlated with most of the evaluated biotic and abiotic factors. Haemoglobin and haematocrit significantly dropped around 40 days after exposing GSB to S. chrysophrii. Furthermore, the abundance of eosinophilic granular cells and goblet cells in gill filaments, and splenic melanomacrophagic centres increased. In contrast, hepatic fat was depleted in S. chrysophrii-infected GSB. This study provides an advancement not only for studying S. chrysophrii's biology and its interaction with its host, but also for further studying the disease under experimental conditions in search of treatment alternatives and prophylactic measures.

Survival Rate Lemon Fish (Rachycentron canadum) Larvae in Lampung Marine Aquaculture Center

Cobia fish (Rachycentron canadum) is one of the marine carnivorous fish that is relatively new and has the potential to be cultuvited. This study aims to determine the effectiveness of larval rearing and nursery cobia fish found in the Center for Marine Aquaculture (BBPBL) Lampung. Held 20 January to 19 February 2021. The mature fish were mated in a 2x2x1 m concrete tank filled with 4,000 L of water. The eggs produced were harvested using an egg collector, counted and hatched in a 0.8x0.6x0.5 m aquarium. After hatching, the larvae were moved into nursery tanks with a density of 5-7 fish/liter. Larvae were reared until they were 25 days old and fed naturally with Branchionus sp, Nannochloropsis sp, and artemia. The larvae were then counted, weighed, measured, graded and their growth analyzed. The results of this study showed that not all of these cobia eggs were fertilized by male cobia sperm at the time of spawning. Spawning was carried out on January 16, 2022. Total eggs was 648,000, total fertilized eggs was 480,000 and fertilization rate was 74.04 %. The results of the initial larval count were 75,000, 17,040 were harvested with a survival rate of 22.72%. Water quality (pH, DO, temperature, salinity, nitrite and ammonia) during the research was still normal.

Investigating the effect of the number of daily egg collecting times on the grade percentage of hatchable eggs, egg weight, weight of the hatched chicken, broken and cracked egg percentage in broiler parent stock farm

This experiment has been conducted for investigating the effect of the number of hatchable eggs’ daily collecting times on such indices as egg weight, the weight of the fertilized eggs and percentage of the cracked and broken egg in the broiler parent stock. The study was carried out on 46-week-old Arbor Acers Plus Chicken within a completely randomized block design with four treatments and 6 replications for 24 days. Every replication was conducted in a single day in such a way that eggs were collected twice, four times, six times and eight times respectively on the first, second, third and fourth day. These fourfold treatments, i.e. twice, four times, six times and eight times of egg collecting were replicated six times. Eggs’ weights were measured daily and the percentage of the daily production, grade percentage of the hatchable farm-raised eggs, percentage of broken and cracked and infected eggs were recorded on farm.

Climate change affects bird nesting phenology: Comparing contemporary field and historical museum nesting records.

Global climate change impacts species and ecosystems in potentially harmful ways. For migratory bird species, earlier spring warm-up could lead to a mismatch between nesting activities and food availability. CO2 provides a useful proxy for temperature and an environmental indicator of climate change when temperature data are not available for an entire time series. Our objectives were to (a) examine nesting phenology over time; (b) determine how nesting phenology relates to changes in atmospheric CO2 concentration; and (c) demonstrate the usefulness of historical museum collections combined with modern observations for trend analyses. We assessed changes in nesting dates of 72 bird species in the Upper Midwest of the United States by comparing contemporary lay dates with those obtained from archived, historical museum nest records over a 143-year period (1872-2015). Species-specific changes in lay date per one unit change in the CO2 residual ranged from -0.75 (95% CI: -1.57 to -0.10) to 0.45 (95% CI: -0.29 to 1.43). Overall, lay dates advanced ~10days over the 143-year period. Resident, short-distance migrants and long-distance migrants lay dates advanced by ~15, 18 and 16days on average respectively. Twenty-four species (33.3%) significantly advanced, one (1.4%) significantly delayed and we failed to detect an advance or delay in lay date for 47 species (65.3%). Overall mean advance in first lay date (for the species that have significantly advanced laying date) was 25.1days (min: 10.7, max: 49.9). Our study highlights the scientific importance of both data gathering and archiving through time to understand phenological change. The detailed archived information reported by egg collectors provide the early data of our study. As with studies of egg-shell thinning and pesticide exposure, our use of these data illustrates another scientific utility of egg collections that these pioneer naturalists never imagined. As museums archive historical data, these locations are also ideal candidates to store contemporary field data as it is collected. Together, such information will provide the ability to track, understand and perhaps predict responses to human-driven environmental change.

Policy implications based on stakeholders’ perceptions for integrated management of the Halda River: Bangabandhu Fisheries Heritage of Bangladesh

Abstract The Halda River of Chattogram is an icon being the only tidal river supporting the spawning of the genetically pure major Indian carp species. Halda is declared as the Bangabandhu Fisheries Heritage due to the broader support for movement towards its conservation. Discrete studies addressed water quality, land-use changes, ecosystem valuation, etc. without taking an integrated heritage conservation approach. This study aims to elucidate priority policy interventions for its integrated management by mapping significant constraints against Halda conservation. Published journal articles, newspaper reports, and reports on Halda from different organizations served as secondary information sources. Primary data were collected using structured questionnaires from 132 respondents from the egg collectors, tobacco farmers, and the rubber dam irrigation project users living in three Upazilas adjacent to the Halda River – Manikchhari, Hathazari, and Raozan. Key informant interviews were taken from the professionals of government and non-government institutions and researchers. Egg collectors appreciated the Upazila administration (65%) and the Department of Fisheries (48%) as effectively working institutions. Administrative bodies marked pollution (73%) as the main challenge in Halda conservation. Based on findings, recommendations were made which may assist the policymakers in developing strategies for integrated management of the river.

As rare as hen’s teeth: aberrantly coloured eggs of the northern lapwing (Vanellus vanellus) and the interface between oology and ornithology

The majority of birds lay eggs of a colour and maculation “typical” of their species, but very occasionally individual females produce eggs of unusual colours. In the past, such eggs were often the target of egg collectors. Four trays of unusually coloured northern lapwing Vanellus vanellus eggs originally accumulated by two notable collectors, F.C.R. Jourdain and J. M. Goodall in the late 1800s and early 1900s, were recovered from the home of David Wilson after his death in 2020. Wilson had acquired this lapwing material, comprising 91 clutches and 347 eggs in total, from the avid collector and millionaire, Captain Vivian Hewitt after Hewitt’s death in 1965. The lapwing clutches are unusual both in terms of their colours, ranging from pale blue with almost no maculation (“cyanic”), through to red (“erythristic”), but also in terms of the completeness of their accompanying data. During the 1800s and early 1900s, hundreds of thousands of lapwing eggs were collected annually in Britain and the Netherlands for human consumption, providing egg collectors, like Goodall and Jourdain, the opportunity to screen large numbers of clutches and acquire rare types. The occurrence of rare egg types in museum egg collections have the potential to provide opportunities to better understand the normal physiological and genetic bases of avian egg colour.

PROSES PENANGANAN TELUR KERAPU TIKUS (Cromileptes Altivelis) DI BBRBLPP GONDOL

The purpose of this study was to determine the process of handling humpback grouper eggs (Cromileptes altivelis) at BBRBLPP Gondol Bali. The data collection method was carried out by means of observation, active participation and direct interviews. The process of handling humpback grouper eggs includes the process of handling initial eggs, egg selection, egg counting and egg observation. The initial handling of humpback grouper eggs begins with harvesting eggs which are carried out in the morning in an egg storage tank that has an egg collector installed. Egg selection is done to separate eggs of good quality and not good. Good quality eggs will float on the surface, are round, transparent and have a core. Quality eggs will not sink to the bottom and are milky white. The egg-calculation technique uses the manual method with the help of a petri dish and a 20 ml glass beaker. The results of the calculation of eggs obtained in one spawning of humpback grouper produced around 670,000 eggs for one broodstock pond of humpback grouper. Eggs using a 40x magnification microscope. The fertilized egg has a transverse line between the nucleus of the egg which is a developing embryo. The unfertilized egg does not have a transverse line which indicates the egg does not have an embryo.

Characterization of spawning rhythms of a sparidae aquaculture species, the white seabream ( Diplodus sargus ), in the south of Portugal

One of the most visible features of fish reproduction is seasonality; however, daily rhythmicity is present in most species and should not be disregarded. This study investigated the seasonal and daily spawning rhythms of the white seabream (Diplodus sargus) in captivity, and a possible endogenous control of the daily rhythm. Spawns were monitored daily, during an entire reproductive season by using an automatic and programmable egg collector. The spawning season lasted 5 months, from January until June, when temperatures oscillated between 11.5 and 24.4°C. Female fecundity was higher between 17.5 and 20.4°C, suggesting a temperature influence in spawning. This species showed a very clear daily spawning rhythm (Cosinor analysis, p < 0.001), strongly related with photoperiod. Eggs started to be released at sunset and peaked around 21:00 h. Egg quality parameters also changed along the spawning period, with viability and hatching rates, increasing towards the end of the night period. The spawning rhythm persisted (Cosinor analysis, p < 0.001) for 5 days under constant light conditions, suggesting the presence of an endogenous clock mechanism which controlled this circadian pattern. The present results represent an advantage for the optimization of egg production protocols in this species, and an added value to the current knowledge of marine fish physiology.

‘A Menace to England’: The Egg Collector as Arch-Villain in Two 1940s Bird Novels

This paper examines the figure of the egg collector as an arch-villain in two novels about rare birds that were published in the 1940s: Adventure Lit Their Star by Kenneth Allsop, and The Awl Birds by J.K. Stanford. Drawing on insights from birdwatching literature published in the same period, I demonstrate that the extreme vilification of the egg collector in both texts represents a dramatic change in attitude towards a pastime that was previously considered beneficial for both adults and children. This about-face, I suggest, can be explained by reading the desperate rush to protect the birds’ eggs as an expression of deep contemporary anxieties over the future of Britain after the Second World War, and in particular a concern that the failures of the period after the First World War should not be repeated.

Massively parallel sequencing and capillary electrophoresis of a novel panel of falcon STRs: Concordance with minisatellite DNA profiles from historical wildlife crime

Birds of prey have suffered persecution for centuries through trapping, shooting, poisoning and theft from the wild to meet the demand from egg collectors and falconers; they were also amongst the earliest beneficiaries of DNA testing in wildlife forensics. Here we report the identification and characterisation of 14 novel tetramer, pentamer and hexamer short tandem repeat (STR) markers which can be typed either by capillary electrophoresis or massively parallel sequencing (MPS) and apply them to historical casework samples involving 49 peregrine falcons, 30 of which were claimed to be the captively bred offspring of nine pairs. The birds were initially tested in 1994 with a multilocus DNA fingerprinting probe, a sex test and eight single-locus minisatellite probes (SLPs) demonstrating that 23 birds were unrelated to the claimed parents. The multilocus and SLP approaches were highly discriminating but extremely time consuming and required microgram quantities of high molecular weight DNA and the use of radioisotopes. The STR markers displayed between 2 and 21 alleles per locus (mean = 7.6), lengths between 140 and 360 bp, and heterozygosities from 0.4 to 0.93. They produced wholly concordant conclusions with similar discrimination power but in a fraction of the time using a hundred-fold less DNA and with standard forensic equipment. Furthermore, eleven of these STRs were amplified in a single reaction and typed using MPS on the Illumina MiSeq platform revealing eight additional alleles (three with variant repeat structures and five solely due to flanking SNPs) across four loci. This approach gave a random match probability of < 1E-9, and a parental pair false inclusion probability of < 1E-5, with a further ten-fold reduction in the amount of DNA required (~3 ng) and the potential to analyse mixed samples. These STRs will be of value in monitoring wild populations of these key indicator species as well as for testing captive breeding claims and establishing a database of captive raptors. They have the potential to resolve complex cases involving trace, mixed and degraded samples from raptor persecution casework representing a significant advance over the previously applied methods.

MASON, Ian J. and PFITZNER, Gilbert H. Passions in ornithology: a century of Australian egg collectors

MASON, Ian J. and PFITZNER, Gilbert H. <i>Passions in ornithology: a century of Australian egg collectors</i>

Demonstration of a Multiple Drift Net for Aquatic Organisms

Abstract The distribution of drifting semi-buoyant fish eggs within a river is useful for understanding the ecology of pelagic-broadcast spawning fish. The vertical position of semi-buoyant eggs in the water column is an important parameter describing transport processes for these species. We designed a multiple drift net (five rectangular nets attached to a frame) to vertically divide the water column into stacked horizontal layers to sample drifting semi-buoyant particles. We deployed the multiple drift net gear beside Moore egg collectors in a wadeable channel to sample the vertical distribution of semi-buoyant polyacrylamide gel beads as surrogates for fish eggs in the water column. The vertical distribution of beads was predominantly found in the deeper nets of the multiple drift net gear while the surface nets and Moore egg collectors had fewer beads which is similar to the results in other studies of pelagic-broadcast spawning fish. The multiple drift net gear is a tool that demonstrates the capability to sample the water column under variable flow conditions (depth, velocity and turbulence) for field data on the vertical distribution of drifting eggs (or surrogates). These empirical data can quantify drift patterns of eggs for modeling transport and retention in pelagic-broadcast spawning species.

Biogeographies: Transcending anthropocentrism in the Anthropocene

Biogeographies: Transcending anthropocentrism in the Anthropocene

Avian egg collections: museum collection bias driven by shape and size

Avian eggs exhibit substantial intra‐ and interspecific variation in shape, size and colour. Considerable efforts have been made to better understand the evolutionary drivers behind such variation, often using museum egg collections. Usually it is assumed that museum collections accurately represent the variation seen in natural populations, but this may not be the case if there is collection bias. Collection bias may lead to the over‐representation of certain egg traits in collections, due to the aesthetic (or other) preferences of collectors. The aim of this study is to begin to look for the occurrence of potential collection bias in museum egg collections by comparing three shape indices (pointedness/asymmetry, elongation and polar asymmetry) and egg volume between subsets of eggs in museum collections with those of recently sampled eggs in the field for three different bird species: common guillemot Uria aalge, razorbill Alca torda and northern fulmar Fulmarus glacialis. We found no evidence of collection bias in our sampled razorbill and northern fulmar museum collection eggs, but some evidence for a bias in sampled museum collection eggs of common guillemots. Since the guillemot's egg differs from most bird eggs in being pyriform, we suggest that collection bias by historic egg collectors may be more prevalent in species with extreme egg traits. Researchers using museum egg collections to examine questions relating to egg shape should be aware of collection bias risks and consider how to minimise the effect of these possible biases on accumulated datasets.

First description of neonate Batagur trivittata (Testudines: Geoemydidae).

The Burmese Roofed Turtle (Batagur trivittata Duméril Bibron, 1835) is a large (straight-line carapace length [CL] to 620 mm; Platt et al., 2019), aquatic, herbivorous turtle endemic to the major river systems of Myanmar (Smith 1931; TTWG 2017). Although historically widespread and apparently abundant, long-term population declines resulted from chronic egg collecting, subsistence harvesting of adults, and loss of critical nesting habitat (Platt et al. 2017a). By the late 1990s B. trivittata was considered a candidate for Extinct status (Bhupathy et al. 2000) until a living specimen purchased in a Chinese wildlife market came into the possession of an American turtle collector in the early 2000s (Platt et al. 2005; W.P. McCord, pers. comm.). Shortly thereafter, field surveys "rediscovered" two remnant populations in the Dokhtawady and upper Chindwin Rivers (Platt et al. 2005; Kuchling et al. 2006). Intense ex- and in-situ recovery efforts were launched shortly thereafter and continue today (Kuchling Tint Lwin 2004; Çilingir et al. 2017).

Assessments of Maleo Macrocephalon maleo nesting grounds in South-east Sulawesi reveal severely threatened populations

SummaryThe Maleo Macrocephalon Maleo is a megapode bird endemic to Sulawesi, Indonesia, that lays large eggs at communal nesting grounds in naturally-heated sands or soils. It is classified as ‘Endangered’ and many populations have been extirpated due to overexploitation of eggs and loss of connectivity between forest and nesting grounds. The distribution and status of nesting grounds across Northern and Central Sulawesi are relatively well-established, but almost nothing is known about potential Maleo populations of South-east Sulawesi. In this study we used previously established methods to formally assess the status of three Maleo nesting grounds in Buton, South-east Sulawesi, and interviewed egg collectors at these three sites to determine the trends of populations and threats over time. All nesting grounds were severely threatened and can be expected to be abandoned in the near future due to extensive harvest of eggs and deforestation. Eggs were collected both for the wildlife trade (intensively harvested and sold as luxury items to people from distant cities) and local use (opportunistically harvested and both eaten and sold locally). All egg collectors remarked on an increase in illegal logging around nesting grounds over the previous decade. Though the Maleo’s current situation is dire, previous case studies show that collaborative grassroots initiatives supported by government and NGOs can protect nesting grounds and reverse population declines.