scholarly journals Some features of embryonic development of eggs and larvae of three stripe rockfsh Sebastes trivittatus (Sebastidae) at Primorye (Japan Sea)

2018 ◽  
Vol 195 ◽  
pp. 146-150
Author(s):  
V. P. Gnyubkina ◽  
A. I. Markevich
Keyword(s):  
Embryonic Development ◽  
Water Temperature ◽  
Japan Sea ◽  
Yolk Sac ◽  
Internal Layers ◽  
External Layer ◽  
Frontal Part ◽  
June July ◽  
Late Stages ◽  
Eggs And Larvae

Later embryonic development ofSebastes trivittatuspasses in 20 days under water temperature 10 оС (in June-July). During this period, the embryos ofS. trivittatusincrease in diameter from 0.1 mm to 1.3 mm and change their shape from spherical to elliptical. Within gonads of pre-hatching females, the embryos have different stages: from prelarvae on late stages of development in the internal layers to pre-hatching larvae in the external layer. The pre-hatching larva hasTL4.1 mm, 5–6 melanophores on the top of head, 20 melanophores in ventral row, some melanophores on peritoneum, and oil globule in the frontal part of intestine; its notochord is not flexed, yolk sac is absent, body myotomes are poor visible, number of tail myotomes is 24.

scholarly journals Early development of the Peruvian rock seabass Paralabrax humeralis (Teleostei: Serranidae): morphological description of the embryonic and yolk-sac larval stages

2021 ◽  
Vol 49 (3) ◽  
pp. 520-525
Author(s):  
Masatoshi Futagawa ◽  
Jessica Pizarro ◽  
German Bueno ◽  
Juan Pablo Díaz
Keyword(s):  
Embryonic Development ◽  
Water Temperature ◽  
Early Development ◽  
Yolk Sac ◽  
Morphological Description ◽  
Cleavage Stage ◽  
Pigmentation Pattern ◽  
Caudal Region ◽  
Larval Stages ◽  
In Captivity

Describe the embryonic development of Paralabrax humeralis (Peruvian rock seabass) and the present morphology of its eggs and yolk-sac larvae using the eggs spawned by P. humeralis broodstock in captivity. The spawning occurred naturally and spontaneously in early November 2018. The egg is pelagic and round, with a diameter of 0.98 ± 0.02 mm, an oil globule, and a diameter of 0.2 ± 0.02 mm. Embryonic development started with meroblastic cleavage, reaching the first cleavage stage at 0.4 h post-fertilization (HPF), and reached 64 cells at 2.2 HPF. Blastula period, 128 cells to 30% epiboly, end at 11.3 HPF. Gastrula period, 50% epiboly to 90% epiboly, end at 19.6 HPF. In the organogenesis period, forming Kupffer’s vesicle appeared at 22.5 HPF, the separation of the caudal fin from the yolk at 30.3 HPF, and the hatching of the first larvae at 47.9 HPF. Water temperature was kept at 17.2 ± 0.2°C. The yolk-sac larvae measured 2.22 ± 0.1 mm with a pigmentation pattern of pinpoint melanophores, all along with the embryo and xanthophores in the cephalic region, trunk, and caudal region, as well as in the oil globule. The larva takes feeds from three days post-hatch-out.

scholarly journals Light and electron microscopy study of late embryonic development in the land snail Limicolaria flammea (Müller) (Pulmonata, Achatinidae)

2007 ◽  
Vol 24 (2) ◽  
pp. 436-441 ◽  
Author(s):  
Rosemary I. Egonmwan
Keyword(s):  
Electron Microscopy ◽  
Embryonic Development ◽  
Light And Electron Microscopy ◽  
Microscopy Study ◽  
Land Snail ◽  
Electron Microscopy Study ◽  
Advanced Embryo ◽  
Embryonic Shell ◽  
Advanced Stages ◽  
Late Stages

The late stages of embryogenesis in the achatinid land snail Limicolariaflammea (Müller, 1774) were described using light and electron microscopy. Embryos at various stages of development were present in the eggs during the first hour after they were laid, from 4-cell blastulae to morulae and fairly advanced stages. The advanced embryo which was fully developed on the second day bears a long cephalic sac, first to be developed, attached to the embryo and a podocyst which is attached to the foot of the embryo. Both of these structures are reduced in size as embryogenesis progresses until they finally disappear at about the 7th day after the egg was deposited. The embryonic shell was apparent on the second day and spiral coiling was apparent at about day 5. The spiral shell had one whorl when formed and more spirals were added so that at hatching the young snails had three whorls.

Lake stratification and temperature profiles simulated using downscaled GCM output

1998 ◽  
Vol 38 (11) ◽  
pp. 217-226 ◽  
Author(s):  
Hany Hassan ◽  
Toshiya Aramaki ◽  
Keisuke Hanaki ◽  
Tomonori Matsuo ◽  
Robert Wilby
Keyword(s):  
Water Temperature ◽  
Flow Direction ◽  
Future Climate Change ◽  
Temperature Profiles ◽  
Downscaling Method ◽  
Surface Climate ◽  
Statistical Relationships ◽  
June July ◽  
The Uk ◽  
Lake Stratification

A mathematical in-lake water temperature model (WATEMP-Lake) was developed to investigate future responses of lake stratification and temperature profiles to future climate change due to rising concentrations of atmospheric greenhouse gases (GHGs). The model was used to simulate daily water temperature profiles and stratification characteristics in summer (June, July, and August-JJA) for Suwa Lake in Japan as a case study. For future assessments, the model uses surface climate variables obtained from a downscaling method that was applied to the UK Hadley Centre's coupled ocean/atmosphere model forced by combined CO2 and sulphate aerosol changes (HadCM2SUL). The downscaling method employed mean sea level surface pressure to derive three airflow indices identified as: the total shear vorticity (Z) -a measure of cyclonicity -, the strength of the resultant flow (F), and the overall flow direction (D). Statistical relationships between these indices and seven daily meteorological time series were formulated to represent climate variable series at sites around Suwa Lake. These relationships were used to downscale the observed climatology of 1979-1995 and that of 2080-2099 using HadCM2SUL outputs.

Ichthyoplankton of the St. Lawrence Estuary: Composition, Distribution, and Abundance

1978 ◽  
Vol 35 (12) ◽  
pp. 1518-1531 ◽  
Author(s):  
Kenneth W. Able
Keyword(s):  
Key Words ◽  
Sampling Period ◽  
Nursery Area ◽  
Composition Distribution ◽  
Lawrence Estuary ◽  
Demersal Eggs ◽  
June July ◽  
Saguenay River ◽  
St Lawrence Estuary ◽  
Eggs And Larvae

The composition, distribution, and abundance of ichthyoplankton in the St. Lawrence estuary, including adjacent portions of the Saguenay River and the northwestern Gulf of St. Lawrence, were investigated during June–July 1973, June–October 1974, and May–September 1975. The eggs and larvae of 25 species from 14 families (principally osmerids, gadids, cottids, cyclopterids, and pleuronectids) were represented. The larvae, in every year, were almost exclusively forms with demersal eggs. Larvae were consistently more abundant in the upper estuary during every sampling period due to its use as a major spawning and nursery area for several species. Both eggs and larvae were most abundant in June and July. Probable spawning times, areas, and growth of larvae are discussed for selected species. Key words: ichthyoplankton, St. Lawrence estuary, distribution, larvae, osmerids, gadids, cottids, cyclopterids, pleuronectids

Abnormal embryonic development induced by antibodies to rat visceral yolk-sac endoderm: Isolation of the antigen and localization to microvillar membrane

1985 ◽  
Vol 107 (2) ◽  
pp. 432-441 ◽  
Author(s):  
Christopher C.K. Leung ◽  
Cheng Lee ◽  
Boonlert Cheewatrakoolpong ◽  
David Hilton
Keyword(s):  
Embryonic Development ◽  
Yolk Sac ◽  
Visceral Yolk Sac

Memoirs: The Embryonic Development of the Stick-Insect, Carausius morosus

1936 ◽  
Vol s2-78 (311) ◽  
pp. 487-511
Author(s):  
A. J. THOMAS
Keyword(s):  
Embryonic Development ◽  
Stick Insect ◽  
Malpighian Tubules ◽  
Germ Band ◽  
Ventral Plate ◽  
Carausius Morosus ◽  
Gut Epithelium ◽  
Cleavage Nucleus ◽  
Endodermal Cells ◽  
Late Stages

1. The maturation of the egg takes place in the ovarian tube, and is immediately followed by the formation of the cleavagenucleus and its division into many nuclei. 2. The entire products of the cleavage-nucleus migrate to the surface to form the blastoderm. Cleavage of the yolk was not observed even in late stages. Yolk-cells are absent when the blastoderm is being formed. 3. Primitive endodermal cells are proliferated from the middle of the germ-band, and form a membrane between the germ-band and the yolk. The membrane is present only in embryonic stages; some of the cells proliferated wander into the yolk and act as vitellophags. 4. Mesoderm is formed by proliferation of cells from the ventral plate. It is preceded by the formation of a shallow gastrular furrow, and from the bottom of this furrow proliferation takes place. The mesoderm becomes arranged in segmental masses. 5. Two masses of cells proliferated at the anterior and posterior ends of the germ-band are shown to be the endodermal rudiments from which the mid-gut epithelium is formed. The invaginations of the stomodaeum and proctodaeum grow against these masses and carry parts of the proliferating areas near their blind ends. It is shown that the various methods of mid-gut formation which have been described could be reconciled with the process described in Carausius. 6. The hinder end of the mid-gut is flanked by two plates of ectoderm which are forward extensions of the proctodaeum. Into these extensions the Malpighian tubules open, and, as their histology is identical with that of these extensions and widely different from that of the mid-gut, these tubules must be ectodermal in nature. 7. The formation of the amnion and serosa are described.

In situ hybridization reveals co-expression of embryonic and adult alpha globin genes in the earliest murine erythrocyte progenitors

Development ◽  
1992 ◽  
Vol 116 (4) ◽  
pp. 1041-1049 ◽  
Author(s):  
A. Leder ◽  
A. Kuo ◽  
M.M. Shen ◽  
P. Leder
Keyword(s):  
In Situ Hybridization ◽  
Embryonic Development ◽  
Fetal Liver ◽  
Globin Gene ◽  
Yolk Sac ◽  
Globin Genes ◽  
Globin Mrna ◽  
Mature Adult ◽  
Alpha Globin

Murine erythropoiesis begins with the formation of primitive red blood cells in the blood islands of the embryonic yolk sac on day 7.5 of gestation. By analogy to human erythropoiesis, it has been thought that there is a gradual switch from the exclusive expression of the embryonic alpha-like globin (zeta) to the mature adult form (alpha) in these early mouse cells. We have used in situ hybridization to assess expression of these two globin genes during embryonic development. In contrast to what might have been expected, we find that there is simultaneous expression of both zeta and alpha genes from the very onset of erythropoiesis in the yolk sac. At no time could we detect expression of embryonic zeta globin mRNA without concomitant expression of adult alpha globin mRNA. Indeed, adult alpha transcripts exceed those of embryonic zeta in the earliest red cell precursors. Moreover, the pattern of hybridization reveals co-expression of both genes within the same cells. Even in the fetal liver, which supersedes the yolk sac as the major site of murine fetal erythropoiesis, there is a brief co-expression of zeta and alpha genes followed by the exclusive expression of the adult alpha genes. These data indicate an important difference in hematopoietic ontogeny between mouse and that of human, where zeta expression precedes that of alpha. In addition to resolving the embryonic expression of these globin genes, our results suggest that the embryonic alpha-like globin gene zeta may be physiologically redundant, even during the earliest stages of embryonic development.

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