Larval and juvenile development of the doughboy scallop, Chlamys (Chlamys) asperrimus (Lamarck) (Mollusca : Pectinidae)

1984 ◽  
Vol 35 (3) ◽  
pp. 315 ◽  
Author(s):  
RA Rose ◽  
TG Dix
Keyword(s):  
The Other ◽  
Allometric Growth ◽  
Hinge Line ◽  
Larval Stages ◽  
Mean Diameter ◽  
Planktotrophic Larvae ◽  
The Right ◽  
Relationship Of ◽  
Juvenile Development ◽  
Early Larvae

Planktotrophic larvae of C. asperrimus were reared from zygotes with a mean diameter of 61.5�m. The smallest straight-hinged larval shell was 80�m long, and slightly protruding umbones were formed 6 days after fertilization. The length (L) and height (H) relationship of larval shells was described by the allometric growth curve H = 0.309 L1 203. Provincular structure of 13-day-old larval shells was simple and there were nine taxodontal teeth per valve, four at one end of the hinge line and five at the other end. Eye spots were conspicuous and common in pediveligers 160-220�m long. Metamorphosis occurred 20-22 days after fertilization at 17-18�C when larvae were 190�m or longer. Larvae settled on monofilament nylon collectors. Newly settled juveniles developed a distinctive byssal notch on the right valve but attachment by byssal threads was never permanent. The small size of eggs and early larvae and allometric growth of prodissoconch II shells are the most significant characteristics distinguishing the larval stages of C. asperrimus from other pectinids in Tasmanian waters.

Larval development of the saucer scallop Amusium balloti (Bernardi) (Mollusca : Pectinidae)

1988 ◽  
Vol 39 (2) ◽  
pp. 153 ◽  
Author(s):  
RA Rose ◽  
GR Campbell ◽  
SG Sanders
Keyword(s):  
Larval Development ◽  
Growth Curve ◽  
Shell Length ◽  
Growth Equation ◽  
Allometric Growth ◽  
Hinge Line ◽  
Statistical Comparison ◽  
The Right ◽  
Relationship Of ◽  
General Appearance

Larvae of A. balloti from Queensland and Western Australia were reared from ova with diameters ranging from 57 to 86�m. The straight-hinged veligers grew in shell length from 85 to 163 �m. Moderately protruding umbones developed 8 days after fertilization. The length (L) and height (H) relationship of larval shells was described by the allometric growth curve: H = 0.600L1.064. The provinculum of 15-day-old larval shells was undifferentiated and each valve had taxodontal teeth, at each end of the hinge line. Eye spots were present and common in pediveligers of 162-242 �m in length. Metamorphosis began 20 days after fertilization at 18-19� C when larvae were 178�m or longer. Settlement began on the 22nd day and lasted 5 days. Newly settled spat developed a byssal notch on the right valve, but attachment by byssal threads was never permanent. The length (L) and height (H) relationships of spat shells was described by the allometric growth equation H = 1.782L0.857. General appearance of A. balloti larvae was comparable to that of other pectinids. Statistical comparison of height-length relationships of the larval shells of A. balloti and Chlamys asperrimus showed larvae of A. balloti to be the more oblong at lengths greater than 128�m. The most significant characteristic of A. balloti spat shells was the formation of rounded auricles at the end of the hinge-line of each valve.

Larval and juvenile development of the Iceland cockle Ciliatocardium ciliatum (Fabricius, 1780) (Bivalvia: Cardiidae)

2020 ◽  
Vol 324 (2) ◽  
pp. 242-251
Author(s):  
L.P. Flyachinskaya ◽  
P.A. Lezin
Keyword(s):  
Lateral Position ◽  
Larval Shell ◽  
Subtidal Zone ◽  
Larval Stages ◽  
Posterior Shoulder ◽  
Blade Shape ◽  
The Right ◽  
Lateral Structures ◽  
Juvenile Development ◽  
Concentric Structure

The paper considers the development of Ciliatocardium ciliatum from the stage of straight hinge to juvenile. In the White Sea the spawning of C. ciliatum begins at the end of June, larvae at different stages of development occur in plankton until the end of September. The earliest of the larvae found had shell lengths of 123–130 µm. The paper first examined the anatomy and structure of the larval shell of C. ciliatum. During the development, the main stages of organogenesis were described and special attention was paid to the formation of the digestive and muscular systems. The digestive system begins to function when the larva reaches a size of 170–180 µm. The digestive gland has a two-blade shape and is shifted to the right side. The foot is formed at a size of 230 µm, the gill rudiments appear when the larva reaches 270 µm. The development of the larval shell and larval hinge of the mollusc is considered in detail. The development of the larval shell of C. ciliatum is similar to the development of other family members. Throughout all the larval stages, the shell has a rounded shape with a low umbos, and the prodissoconch II has a clearly visible concentric structure. The C. ciliatum larval hinge is characterized by weak differentiation and the absence of pronounced cardinal teeth typical for other Cardiidae. However, the lateral structures of the castle – ridges and flanges – are well developed. The ligament begins to form at a size of 240–250 µm and occupies a lateral position. The settlement of the cockle takes place in September in the subtidal zone. After the metamorphosis, a large radial sculpture is formed on the dissoconch and a number of small spikes are formed at the rib of the posterior shoulder.

The larval development of three species ofMagelona(Polychaeta) from localities near Plymouth

1982 ◽  
Vol 62 (2) ◽  
pp. 385-401 ◽  
Author(s):  
Douglas P. Wilson
Keyword(s):  
Larval Development ◽  
Equal Length ◽  
The Other ◽  
The Right ◽  
Early Larvae ◽  
Made In

Fertilizations ofMagelona filiformis, M. alleni, andM. mirabiliswere made in the laboratory and the resulting larvae reared through the earliest stages. Later stages of all three species were obtained from the plankton and induced to metamorphose in the laboratory. The long larval tentacles derive from the prototroch and associated tissues. Adult tentacles appear during later pelagic life as thickenings at the bases of the larval tentacles; the latter, together with the long provisional bristles, are discarded at metamorphosis. The early larvae ofM. alleniare considerably larger than equivalent stages of the other two species. The early larvae ofM. mirabilisare peculiar in that at first the larval tentacle of the left side is a mere stump while that of the right side is relatively large; in the other two species both tentacles are of equal length. Larvae of the three species are readily identifiable by characters described in the text.

Sex Inequality and Bias in Sex Differences Research

1987 ◽  
Vol 13 ◽  
pp. 24-39 ◽  
Author(s):  
Alison M. Jaggar
Keyword(s):  
Sex Differences ◽  
Scientific Discourse ◽  
Sibling Rivalry ◽  
The Other ◽  
Scientific Advance ◽  
The World ◽  
Siamese Twin ◽  
The Right ◽  
Relationship Of ◽  
The Relationship

The relationship of philosophy to science is a matter of long historical dispute. Philosophy has been described variously as the mother, the queen or the handmaiden of science, depending on whether the philosopher’s role was perceived as that of giving birth to science, of regulating and legitimating scientific discourse or of clearing the conceptual underbrush in the way of scientific advance. This essay, by contrast, is grounded on a conception of philosophy and science as partners or sisters, perhaps even as Siamese twin sisters, both proceeding from the same impulse to understand ourselves and the world and to change both for the better. Occasionally relations between philosophy and science have been marred by sibling rivalry, with each sister claiming the right to control and limit the pretensions of the other. In fact, however, philosophy and science are interdependent and ultimately inseparable. To borrow a famous slogan from another context: science without philosophy is blind; philosophy without science is empty.

Eigentum und Erbrecht

Der Staat ◽  
2020 ◽  
Vol 59 (3) ◽  
pp. 397-420
Author(s):  
Jan Dirk Harke
Keyword(s):  
Fundamental Difference ◽  
The Other ◽  
Private Law ◽  
Absolute Power ◽  
Other Hand ◽  
Constitutional Right ◽  
The Right ◽  
Relationship Of

,Eigentum‘ im Sinne der Verfassung ist bekanntermaßen nicht deckungsgleich mit ,Eigentum‘ im Sinne des Privatrechts. Beide stehen nicht bloß in einem Verhältnis von Mehr und Weniger, sondern sind durch einen fundamentalen Unterschied getrennt: Das privatrechtliche Eigentum ist anders als sein verfassungsrechtliches Pendant untrennbar mit dem Erbrecht verbunden und verdankt ihm sogar seine Entstehung. Den absoluten Geltungsanspruch, der es charakterisiert, kann es nur haben, wenn es auch über den Tod seines Inhabers hinaus wirkt. Das verfassungsrechtliche Eigentum knüpft dagegen allein an das Vertrauen an, das der Gesetzgeber durch eine Regelung beim Einzelnen geweckt hat. Es ist dementsprechend auch ohne Erbrecht denkbar und hat sich von diesem im Zuge der Konstitutionalisierung in einem Prozess geschieden, der die Etablierung des privatrechtlichen Eigentumsbegriffs umkehrte. Soweit der Gesetzgeber aber Eigentum im Sinne des bürgerlichen Rechts als solches anerkannt hat, setzt es dem staatlichen Umgang mit der Erbfolge Grenzen. As is well known, "property" as a constitutional right is not congruent with "property" in the sense of private law. The two are not merely in a relationship of more and less, but separated by a fundamental difference: Unlike its constitutional counterpart, property under private law is inseparably connected with the right of succession and even owes its origin to it. It can only have its characteristic absolute power, if it continues to have an effect beyond the death of its owner. Property as a constitutional right, on the other hand, is based solely on the trust that legislature has aroused in an individual through regulation. Accordingly, it is also conceivable without right to inheritance, and in the course of constitutionalization it has been separated from the latter in a process that reversed the emergence of the private law concept of property. However, insofar as legislature has recognized property in the sense of private law, it sets limits on the regulation of succession.

PECULIARITY OF THE LEGAL RELATIONSHIP OF ENVIRONMENTAL LAW

2021 ◽  
pp. 88-97
Author(s):  
Andrian Cretu ◽  
◽  
◽  
Keyword(s):  
Natural Resources ◽  
Large Scale ◽  
Raw Materials ◽  
Environmental Law ◽  
The Other ◽  
Unintended Effects ◽  
Legal Relationship ◽  
Intensive Exploitation ◽  
The Right ◽  
Relationship Of

The possibilities of man to turn natural resources into sources of profit have led the legislator and the right, in general, to resort to much tougher regulations in the field of environmental protection, this could not be possible without knowing precisely the nature of the legal relationship that would lay the basis for subsequent regulations, and in the doctrinal plan it and today suffers from numerous criticisms, debates and controversies. However, one thing is for certain, the relationship of the environment is one of the particular, double-side, where, on the one hand, it regulates the relations between people are established on the occasion of the use, protection, conservation and development, environmental factors, and by the other hand, it requires the modeling of the principles of the other areas of the law with which they come in contact with, and this is asked for a better connectivity and efficiency in the plan for the defense of the values of the environment, the most valuable in the world is on the verge of collapse, natural. In this sense, the realities of today show that the twentieth century is the time of the greatest discoveries and transformations of civilization, but also the most complex and sometimes unintended effects on life. Not long ago, renewable natural resources of the Earth, would be sufficient for the needs of humanity, but for now, as a result of the population explosion, and the unprecedented development of all areas of the business, the demand for raw materials and energy for the production of goods has increased greatly, and the intensive exploitation of natural resources show more obviously, an ecological imbalance. In the context of large-scale changes that can jeopardize the quality of the environment, it is necessary to consider the intentions underlying the exploitation of environmental resources, emerging from the alarming situation that can no longer be tolerated, risking the survival and existence of the human species.

scholarly journals Konsep Uchi-Soto Dalam Penerjemahan Yari-Morai

2020 ◽  
Vol 8 (1) ◽  
pp. 57-63
Author(s):  
Reny Wiyatasari
Keyword(s):  
The Other ◽  
Data Sources ◽  
Japanese People ◽  
Advanced Technique ◽  
Basic Technique ◽  
Auxiliary Verbs ◽  
Right Relationship ◽  
The Right ◽  
Relationship Of ◽  
The Given

  This study aims to describe the understanding of Japanese language students about the ‘uchi-soto’ concept which is the standard for Japanese people when using the ‘yari-morai’ expression. This also relates to the process of translating speeches containing the verb ‘yari-morai’. Data sources are Japanese manga (Japanese) and a questionnaire that lists structured questions. The method used in data collection is the listening method with tapping technique as the basic technique and the listening-free-engaged-conversation technique as an advanced technique. Whereas in the analysis using contextual and descriptive methods, the sentence is analyzed by explaining the context, the concept of ‘uchi-soto’ in relation to the use of ‘yari-morai’ auxiliary verbs, assessing the results of the translation and relating it to the concept of ‘uchi-soto’ in the linguistic realm. The results of this study indicate 1) in the yaru and ageru verbs, it was found that the respondents' understanding of the uchi-soto concept was the same lack. 2) on the morau verb, the authors found that respondents were able to determine the uchi-soto relationship and 3) in the kureru verb, some respondents can distinguish and determine the uchi-soto relationship well, however, when the kureru verb becomes kudasaru, even though the respondent can still recognize the uchi-soto relationship, some 100% of the translating results of the respondent are incorrect. So, from the students' understanding of the concept of uchi-soto which is associated with the results of translation it is known that it does not significantly correlate with student competence in translating utterances that contain yari-morai verbs and vice versa. Although some respondents answered correctly the uchi-soto relationship of the speakers involved in a conversation, it was not in accordance with the translation that resulted from both accuracy and acceptance. On the other hand, although the respondent is able to translate the fragments from the utterances, it is not able to determine the right relationship between speakers with other parties in the given conversation situation. Keywords: expressions; uchi-soto; yari-morai; translation

scholarly journals Length-weight relationship and condition factor of the mangrove crab Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ucididae)

2009 ◽  
Vol 52 (2) ◽  
pp. 397-406 ◽  
Author(s):  
Marcelo Antonio Amaro Pinheiro ◽  
Ana Gláucia Fiscarelli
Keyword(s):  
Condition Factor ◽  
The Other ◽  
Allometric Growth ◽  
Ucides Cordatus ◽  
Mangrove Crab ◽  
Wet Weight ◽  
The Mean ◽  
Autumn And Winter ◽  
Relationship Of ◽  
The Relationship

The relationship of wet weight (WT) to cephalothorax width (CW) and temporal and seasonal variations in the condition factor were analyzed for each sex of the mangrove crab Ucides cordatus, using specimens collected monthly from September 1998 through September 2000, at Iguape, state of São Paulo. The WT/CW relationship, determined by the regression analysis and the condition factor were evaluated individually, monthly and seasonally, for each sex. The WT/CW relationship indicated isometric growth in males and negative allometric growth in females. Body weight was higher in males than in females of equivalent size and this difference was associated with the males' faster growth and heavier chelipeds. On the other hand, the means for condition factor were always higher for females than for males; the mean condition factor was lower in spring and summer and higher in autumn and winter.

Memoirs: The Development of the Sabellid Branchiomma vesiculosum

1936 ◽  
Vol s2-78 (312) ◽  
pp. 543-603
Author(s):  
DOUGLAS P. WILSON
Keyword(s):  
The Body ◽  
Limited Extent ◽  
Present Position ◽  
Larval Stages ◽  
Large Head ◽  
Dorsal Branch ◽  
The Right ◽  
Longitudinal Muscles ◽  
Young Worm ◽  
Early Larvae

1. Larvae of Branchiomma vesiculosum Montagu were obtained from artificial fertilizations, and reared through metamorphosis and for some weeks afterwards. 2. The larvae are extremely yolky and do not feed until after metamorphosis. They swim by means of a broad prototroch, and are provided with a pair of cup-shaped eye-spots, a large head vesicle, and two anal vesicles. There is a broad neurotroch but no telotroch. The mouth is open but the anus is closed. In the last swimming stages rudiments of the adult branchial apparatus appear as a pair of lobed swellings, behind the eyes but in front of the prototroch. Behind the latter the collar rudiments appear. There are usually three or four chaetigerous segments marked out when metamorphosis sets in. 3. The metamorphosing larva settles on the bottom, and secretes for itself a tube of mucus. The prototroch and larval tissues (episphere) of the head clump together to form a large snout-like structure. This gradually breaks up into small pieces which are thrown off one by one as they are formed. With the loss of the prototroch and other larval head tissues the adult part of the head becomes joined on to the trunk. At the same time the branchial rudiments branch to form pinnules, which are directed forwards so that their bases overlap the eyes. The anus opens, and the young worm begins to feed. Metamorphosis occupies about four days. 4. The larval stages and the metamorphosis have been studied in histological, and to a limited extent in cytological, detail. Apart from the curious metamorphosis, which to some extent recalls that of Owenia and Polygordius, the development shows no striking features. 5. After metamorphosis the worm elongates by the addition of setigers in front of the pygidium. These are at first of the thoracic type (dorsal bristles, ventral uncini), but when the ninth and succeeding setigers appear they show abdominal constitution (dorsal uncini, ventral bristles) from the first. Thus no setigers change over from abdominal to thoracic constitution as they do in the development of young Serpulid worms. 6. Coincident with the loss of the neurotroch at metamorphosis the mid-dorsal line of the head and trunk of the young worm becomes ciliated to form the faecal groove of the adult. This strip of cilia continues on the ventral surfaces of the ninth and succeeding setigers, after passing round the right side between the eighth and ninth bristle segments. For a time the intersegmental groove between these segments is ciliated on the left side as well. 7. The branchial rudiments, which began to branch before metamorphosis, continue steadily to branch and grow afterwards. The pinnules are supported by an internal skeleton of thick-walled cells to the base of which the main dorsal and ventral longitudinal muscles of the body become attached. The most dorsal branch of each branchial rudiment, lying close to the mid-dorsal line, forms one of the so-called palps of the adult and is not supported by an internal skeleton. 8. The manner in which the young worms build their first sandy tube is described. 9. Early larvae of Sabella pavonina (Savigny) are described. They closely resemble those of Branchiomma. 10. The present position of embryological knowledge concerning the Polychaetes is very briefly summarized. It is shown that Sabellid larvae are more closely related to Serpulids than to those of any other family.

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