Delayed determination of claw laterality in lobsters loss of target

Development ◽  
1989 ◽  
Vol 107 (3) ◽  
pp. 547-551
Author(s):  
C.K. Govind ◽  
J. Pearce
Keyword(s):  
Critical Period ◽  
Early Juvenile ◽  
Juvenile Stages ◽  
Juvenile Development

Lateralization of the paired claws into a major crusher minor cutter type is determined during the 4th and 5th juvenile development of the lobster, Homarus claws during this critical period delays the laterality until the 6th stage when regenerate claws Continued loss into the 6th stage, and beyond, laterality, resulting in lobsters with paired cutter critical period for determining claw laterality may extended for a brief time to cater for claw loss, common in these early juvenile stages.

scholarly journals Decapodid and early juvenile development in the protandrous shrimp Campylonotus vagans (Crustacea: Decapoda: Caridea), with notes on larval morphology

2003 ◽  
Vol 83 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Sven Thatje ◽  
Gustavo A. Lovrich
Keyword(s):  
Low Temperatures ◽  
Juvenile Stage ◽  
Tierra Del Fuego ◽  
Caridean Shrimp ◽  
Early Juvenile ◽  
Morphological Variations ◽  
Sexual Determination ◽  
Juvenile Stages ◽  
Two Stages ◽  
Juvenile Development

The decapodid and first two juvenile stages of the caridean shrimp Campylonotus vagans from the Subantarctic Beagle Channel (Tierra del Fuego, Argentina) are described and illustrated in detail. The complete larval and early juvenile development of this species from rearings under controlled laboratory conditions were analysed. Zoeal morphology in two stages of an abbreviated development was identical to a description from plankton and hatched larvae of a previous work, and therefore we only compare and discuss slight morphological variations in this study. The first juvenile is large and already resembles some features of adults, lacking all ventral rostral and the fourth dorsal rostral spine only which appears in the following stage, and the second pereiopod not yet being as predominant as in adults. Sexual determination is not yet possible up to the described second juvenile stage. The abbreviated larval development in a Subantarctic shrimp species is discussed as an adaptation to low temperatures and pronounced seasonality.

scholarly journals The megalopa and early juvenile development of Hepatus pudibundus (Crustacea: Brachyura: Aethroidea) reared from neuston samples

2008 ◽  
Vol 25 (4) ◽  
pp. 608-616 ◽  
Author(s):  
Maria L. Negreiros-Fransozo ◽  
Adilson Fransozo ◽  
Gustavo L. Hirose
Keyword(s):  
Intraspecific Variation ◽  
Shallow Waters ◽  
Larval Morphology ◽  
Western Atlantic ◽  
Laboratory Rearing ◽  
Early Juvenile ◽  
Levels Of Detail ◽  
Juvenile Stages ◽  
Juvenile Crab ◽  
Juvenile Development

Hepatus pudibundus (Herbst, 1785) is a crab commonly found in shallow waters of the Western Atlantic. Its larval and early post-larval morphology have already been described from laboratory hatched material. Around 200 megalopae of H. pudibundus were collected in neuston samples from the Ubatuba region, Brazil, during the summer of 2005-2006 and were successfully reared under laboratory conditions. The size of the megalopae obtained in the neuston was similar to those specimens previously described in the literature, except that the juvenile crab stages reared in the laboratory were slightly larger, probably due to the better feeding conditions in the laboratory. The duration of the juvenile stages was shorter in the present study than in previous attempts at laboratory rearing, even if conditions appeared to be similar. The main differences observed between studies were in megalopal morphology, which may be attributable to intraspecific variation but, possibly, also due to differences in levels of detail than previously performed.

scholarly journals Scolex development, morphology and mode of attachment of Wenyonia virilis Woodland, 1923 (Cestoidea, Caryophyllidea)

2006 ◽  
Vol 51 (1) ◽  
Author(s):  
Mohammed Ibraheem ◽  
John Mackiewicz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Host Tissue ◽  
Central Group ◽  
Early Juvenile ◽  
Juvenile Stages ◽  
Mode Of Attachment ◽  
Terminal Structure ◽  
Juvenile Development ◽  
Scanning Electron

AbstractDevelopment and morphology of the scolex and mode of attachment of Wenyonia virilis Woodland, 1923, a caryophyllaeid cestode from the silurid Nile fish Synodontis schall (Bloch et Schneider, 1801), were studied by means of light and scanning electron microscopy (SEM). Scolex and genital primordia changes through four stages of juvenile development are described. Longitudinal ridges do not appear on the scolex until the cestode has well defined genital primordia. This is in stark contrast to other caryophyllidean genera in which the basic morphology of the adult scolex becomes evident at the procercoid stage in the oligochaete intermediate host. The scolex of the adult has 13 to 19 prominent longitudinal ridges and deep furrows that come together at the apex to form an apical ring, a protrusible terminal introvert within the apical ring that forms a deep apical pouch when fully retracted, and a central group of Faserzellen. The scolex of W. virilis appears similar to the rugomonobothriate scolex of another African caryophyllid, Monobothrioides chalmersius (Woodland, 1924). Comparisons are made with other caryophyllideans having a scolex with a terminal structure: Monobothrium Diesing, 1863, Djombangia Bovien, 1926 and Caryoaustralus Mackiewicz et Blair, 1980. The terminal introvert may be responsible for attachment in early juvenile stages, but may be supplemented by the longitudinal ridges and furrows later in development. Host tissue appears to be drawn into these furrows that function as weak organs of attachment. We could not determine how the introvert of adult worms functions in attachment. At the site of attachment, the mucosa showed necrosis and degeneration and the submucosa exhibited vacuolization and infiltration with lymphocytes and leucocytes.

Classification of the Oxbow Lakes of the Hármas-Körös River and Determination of Ways for Further Exploiting the Various Water Regions in the Light of the Water Framework Directive

2017 ◽  
Author(s):  
Józsa Vilmos ◽  
Jacek Kozłowski ◽  
Anna Zróbek-Sokolnik ◽  
Krzysztof Kozłowski ◽  
Piotr Dynowski
Keyword(s):  
Fishery Management ◽  
Ecological Status ◽  
Anthropogenic Factors ◽  
Oxbow Lakes ◽  
Negative Effect ◽  
Juvenile Stages ◽  
The Individual ◽  
The City

Hármas-Koros river lies between the mouth of the Tisza and the city Békés. In the nineteenth century, the work of regulatory her bed was made, which resulted in 44 oxbow lakes were created, of which 36 still exist till today. In presented work 14 oxbow lakes was selected and the following objectives were carried out: 1. The classification of oxbow lakes based on selected criteria: the manner and intensity of water exchange, sediment thickness, redox potential, usage, ichtiofouna. 2. The assessment of the state of spawning and its impact on ichtiofauna. 3. Determination the best methods of water management in particular types of oxbow lakes, which could stop their further degradation. The obtained results led to the following conclusions: - Tested oxbow lakes belong to different categories - Anthropogenic factors had a negative effect on the conditions of fish reproduction and survival of their juvenile stages. - The management of fisheries was not a factor differentiating the individual water regions, but had an impact on the ecological status. - For the maintenance and/or improvement of the natural environment of the individual oxbow lakes significant impact may have fishery management, carried out in the following years.

scholarly journals The Most Extreme Sexual Size Dimorphism among Birds: Allometry, Selection, and Early Juvenile Development in the Great Bustard (Otis tarda)

The Auk ◽  
2009 ◽  
Vol 126 (3) ◽  
pp. 657-665 ◽  
Author(s):  
Juan C. Alonso ◽  
Marina Magaña ◽  
Javier A. Alonso ◽  
Carlos Palacín ◽  
Carlos A. Martín ◽  
...  
Keyword(s):  
Sexual Size Dimorphism ◽  
Great Bustard ◽  
Size Dimorphism ◽  
Otis Tarda ◽  
Early Juvenile ◽  
Juvenile Development
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