Bad Eggs

Synopsis and review of the Australian feature film Bad Eggs, directed by Tony Martin.

Minimising mortality in field and pot experiments using Heteronyx piceus Blanchard (Coleoptera: Scarabaeidae) eggs and larvae

The establishment of experimental populations of scarab larvae using eggs and early instar larvae has proven to be difficult for many researchers. Despite this, little work has been published examining ways to optimise establishment under artificial conditions. In this experiment, we examined the effect of shade and irrigation on the establishment of Heteronyx piceus Blanchard larvae introduced into pots as eggs and first-, second- and third-instar larvae to optimise artificial infestation techniques. The most important factor affecting larval establishment was the life stage introduced. Establishment of eggs and first instars was very low, with only 21% of eggs and 11% of first-instar larvae establishing. In contrast, 82% of second-instar larvae and 84% of third-instar larvae established successfully. The addition of shade marginally improved overall survival from 45% in the unshaded pots to 53% in the shaded pots. However, most of this increase was in the eggs and first instars. Irrigation did not improve survival. These results suggest that when introducing scarab larvae to field or pot experiments, second- or thirdinstar larvae should be used to maximise establishment. The provision of shade and supplementary irrigation is optional.

Riboflavin carrier protein from carp (C. carpio) eggs: comparison with avian riboflavin carrier protein

A protein exhibiting immunological cross-reactivity with the chicken egg-white riboflavin carrier protein was detected by radioimmunoassay in the eggs and serum of the fresh water fish Cyprinus carpio and subsequently purified to homogeneity by use of affinity chromatography. Fish riboflavin carrier protein resembled chicken riboflavin carrier protein with respect to most of its physicochemical characteristics. The major epitopes of chicken riboflavin carrier protein were shown to be conserved in the fish protein as probed with monoclonal antibodies to the avian vitamin carrier.

Virgin wasps develop ovaries on par with mated females, but lay fewer eggs

In the primitively eusocial wasp Ropalidia marginata, mating is not necessary for a female wasp to develop her ovaries, lay eggs, and even to become the sole egg layer of her colony despite the presence of other mated nestmates. Here, we show that virgin wasps do not differ from their mated counterparts in the extent and rapidity of their ovarian development, in the proportion of individuals that build a nest and laid eggs, and in the time taken to do so. However, a significantly larger proportion of virgin females showed resorbing oocytes, and laid fewer eggs as compared to mated individuals. Thus, virgin females have the ability to develop ovaries and lay eggs but also to refrain from necessarily laying all mature eggs produced, before mating opportunities arise. This dual ability would be adaptive in haplodiploid, tropical species with perennial nesting cycles and frequent opportunities for workers to become replacement queens or solitary nest foundresses throughout the year.

The mechanical effects of water flow on fish eggs and larvae

The impact of mechanical stresses upon ichthyoplankton entrained in power plant cooling systems has long been considered negligible. Arguments and evidence exist, however, to show that such a supposition is not universally true, especially in nuclear power plants. The mechanisms of mechanical damage can be detailed in terms of pressure change, acceleration, and shear stress with in the fluid flow field. Laboratory efforts to quantify the effects of mechanical stress have been very sparse. A well-planned bioassay is urgently needed. (PDF has 11 pages.)

Effects of shear on eggs and larvae of striped bass, morone saxatilis, and white perch, M. americana

Shear stress, generated by water movement, can kill fish eggs and larvae by causing rotation or deformation. Through the use of an experimental apparatus, a series of shear (as dynes/cm2)-mortality equations for fixed time exposures were generated for striped bass and white perch eggs and larvae. Exposure of striped bass eggs to a shear level of 350 dynes/cm2 kills 36% of the eggs in 1 min; 69% in 2 min, and 88% in 4 min; exposure of larvae to 350 dynes/cm2 kills 9.3% in 1 min, 30.0% in 2 min, and 68.1% in 4 min. A shear level of 350 dynes/cm2 kills 38% of the white perch eggs in 1 min, 41% in 2 min, 89% in 5 min, 96% in 10 min, and 98% in 20 min. A shear level of 350 dynes/cm2 applied to white perch larvae destroys 38% of the larvae in 1 min, 52% in 2 min, and 75% in 4 min. Results are experimentally used in conjunction with the determination of shear levels in the Chesapeake and Delaware Canal and ship movement for the estimation of fish egg and larval mortalities in the field.

Distribution patterns of fish eggs in the U.S. Northeast Continental Shelf Ecosystem, 1977-1987

This atlas presents information on fish eggs and temperature data collected from broadscale ichthyoplankton surveys conducted off the U.S. northeast coast from ]977 to 1987. Distribution and abundance information is provided for 33 taxa in the form of graphs and contoured egg-density maps by month and survey. Comments are included on interannual and interseasonal trends in spawning intensity. Data on 14 additional but less numerous taxa are provided in tabular form. (PDF file contains 316 pages.)

Artificial fertilization of the eggs, and rearing and identification of the larvae of the anchoveta, Cetengraulis mysticetus

ENGLISH: The anchoveta, Cetengraulis mysticetus (Günther), is an important bait fish used to capture tunas in the Eastern Tropical Pacific Ocean. Contributions to the early life history of this species in the Gulf of Panama were made by Simpson (1959), who was able to identify deductively the planktonic egg of the anchoveta from 10 other anchovy eggs concurrently present. He also reared these planktonic eggs in the laboratory and described the resultant larvae to the age of 48 hours after hatching. Because of the lack of differences among the anchovy larvae, this description does not permit the identification of anchoveta larvae from those of other engraulid species. Furthermore, while adult specimens are easily recognized, up to the present it has not been possible to extend the identification of the juvenile anchoveta to specimens smaller than about 25 mm. The purpose of this study, therefore, was to identify anchoveta from the time of hatching to about 25 mm. SPANISH: La anchoveta, Cetengraulis mysticetus (Günther), es un importante pez de carnada que se emplea en la captura de los atunes en el Océano Pacífico Oriental Tropical. Simpson (1959) logró identificar deductivamente el huevo planctónico de la anchoveta al separarlo de otros diez huevos de anchoas que se encuentran al mismo tiempo, contribuyendo de esta manera a conocer los primeros estados de la historia natural de esta especie en el Golfo de Panamá. El también estableció un criadero en el laboratorio con estos huevos planctónicos y describió las larvas resultantes hasta la edad de 48 horas después de la eclosión. Debido a que no hay diferencias entre las larvas de las anchoas, esta descripción no permite identificar las larvas de la anchoveta de las otras especies de engráulidos. Más aun, a pesar de que los especímenes adultos son fácilmente reconocibles, hasta ahora no ha sido posible identificar la anchoveta juvenil de menos de unos 25 mm. Consecuentemente, el propósito del presente estudio ha sido el de identificar al anchoveta desde el momento de la eclosión hasta que tiene unos 25 mm.

The First Occurrence in the Fossil Record of an Aquatic Avian Twig-Nest with Phoenicopteriformes Eggs: Evolutionary Implication

14 p.

Eggs of British Meniscus midges (diptera;dixidae) observed by scanning electron microscopy

The egg of Dixella martinii is described for the first time. The eggs of the Dixidae are placed in three morphological groups: bulbous and meshed; streamlined and smooth; streamlined and minutely spiculated. Ten of the fourteen species known from Britain are placed in these groups. After a detailed description of the egg of D. martinii, the three morphological groups are described and scanning electron micrographs are provided.

Effects of suspended sediments on the development of eggs and larvae of striped bass and white perch

The possible ecological effects of suspended sediments are manifold. Briefly, suspended sediments may cause an increased surface for microorganism growth, fewer temperature fluctuations, chemical adsorption or absorption, blanketing, mechanical-abrasive actions, and light penetration reduction (Cairns, 1968). Sherk and Cronin (1970) have pointed out that the above effects have been little studied in the estuarine environment. The ecological effects of suspended sediments on fish eggs and larvae may be of prime importance t o the C and D Canal area, an important spawning and primary nursery area for a variety of estuary: e species (Johnson,1972). This section discusses the effects of suspended sediment on the eggs and larvae of striped bass and white perch.

An identification key of the most important German freshwater teleost fishes by means of their eggs [Translation from: Archiv fur Hydrobiologie 83(2), 200-212, 1978]

The fetal and larval development of many freshwater fish is already relatively well covered. Coverage of the morphology of fish-species' eggs is very sparse. For this reason the authors have attempted to prepare a key on fish eggs which covers the bulk of German Teleostei fish. The key also includes a discussion of problems of categorization and terminology.

Mitochondria and the development of sea urchin embryos

After artificial activation or fertilization of non-nucleate fragments or eggs of the sea urchin, the mitochondria actively synthesize RNA. The RNA made in non-nucleate fragments is shown to be mostly single stranded and to be associated primarily with the low speed pellet of centrifuged cellular homogenates.

Protein synthesis is observed in non-nucleate fragments in the presence or absence of the mitochondrial RNA synthesis: it is found to be qualitatively similar but quantitatively less in the absence of the RNA synthesis. The continued syntheses of proteins in the non-nucleate fragments in the absence of mitochondrial RNA synthesis provides additional evidence for the presence of a stable messenger RNA component in the unfertilized sea urchin egg.

Since the uptake or actinomycin D was found to be inhibited by the presence of a fertilization membrane, ethidium bromide, at 10 μgs/ml, is used as an effective inhibitor of RNA synthesis in non-nucleate fragments and in early cleavage stage embryos. However, this same concentration of ethidium bromide is found to be only partially effective in blocking RNA synthesis at the mesenchyme blastula stage of development.

Low concentrations of ethidium bromide (2 and 5 μgs/ml) are found not to be lethal but to be capable of producing moderate developmental defects. In the presence of concentrations of ethidium bromide adequate to inhibit all the mitochondrial RNA synthesis (10 μgs/ml of ethidium bromide), from fertilization on, the embryos do not cleave beyond the 4-8 cell stages. When similar concentrations of ethidium bromide are added at an early mesenchyme blastula stage, the embryos do not gastrulate but continue to swim for more than 24 additional hours (adequate for control embryos to develop to a late prism stage). These results lead to the conclusion that mitochondrial RNA synthesis may be very essential for normal development to occur.

DNA is synthesized in the non-nucleate fragments of sea urchin eggs. None of the newly synthesized DNA is found in the closed circular form. When phenol extracted directly from the fragments, the DNA is found to sediment at approximately 38 and 27s in sucrose gradients but neither of these size classes could be found associated with the isolated mitochondria. The template for the synthesis of DNA in non-nucleate fragments remains unknown.

The life capacity of copepod's eggs passed through the gut of Ladoga lake Coregonus [Translation from: Zool.Journal.Moscow 29-5, 476-477, 1950]

This short paper summarises findings of experiments that were carried out using copepod eggs taken from guts of Coregonus which breeds in various Ural lakes. The study showed that copepod eggs can pass through the gut of Coregonus unharmed.