background: thyroxine hormone appears to play some role at early stages of development and survival of fish larvae. objectives: the purpose of the present study was to investigate the effect of levothyroxine sodium on hatching and survival rate at early developmental stage of rainbow trout (oncorhynchus mykiss) larvae. methods: this study was carried out in dalkhan propagation and cultivation f...

this study was conducted to examine morphometric and meristic characteristics alongside pigmentation patterns of bream larvae, abramis brama orientalis, in four stages of larval development. morphological characters including total length (tl), standard length (sl), notochord length (nl), head length (hl), head depth (hd), eye diameter (ed) and mouth width (mw) were examined from hatching time ...

background: mosquitoes lay eggs in a wide range of habitats with different physicochemical parameters. ecological data, including physicochemical factors of oviposition sites, play an important role in integrated vector management. those data help the managers to make the best decision in controlling the aquatic stages of vectors especially using source reduction. methods: to study some physico...

Previous studies of energy metabolism in larvae have described a developmental ‘‘point of no return’’ (PNR), a time by which larvae of planktotrophic marine species must feed in order to survive and grow. This study investigated the effects of long-term food deprivation on developing larvae of the oyster Crassostrea gigas with the goal of providing a biochemical and metabolic description of lar...

To test the hypothesis that long-term survival of sugarbeet root maggot in storage is facilitated by larvae undergoing prolonged diapause, respiration and gene expression patterns of field-collected diapausing larvae were compared with those of 1-, 2-, and 5-year laboratory-stored larvae. Additional assessments were made on post-storage survival, emergence, and reproductive fitness of stored la...

The development of Dipetalonema viteae third stage larvae was attempted in vitro. A monophasic culture system consisting of BHK-21 medium supplemented with 10% tryptose-phosphate broth and 15% fresh jird serum allowed the growth of previously in vivo triggered larvae, but not of those isolated from ticks. The larvae could complete their third moult and grew on a fourth stage larvae up to 5 mm. ...

First record of larvae of Chironomidae (Insecta, Diptera) as prey of Temnocephala sp. (Platyhelminthes, Temnocephalidae), an ectosymbiont on larvae of Corydalidae (Megaloptera). This study constitutes the first record of Temnocephala Blanchard, an ectosymbiont on Corydalidae, as a possible predator of chironomid larvae. Twenty-eight Corydalidae larvae (Corydalus and Protochauliodes) were examin...

Honeybee (Apis mellifera) imagines are resistant to the Gram-positive bacterium Paenibacillus larvae (P. larvae), causative agent of American foulbrood (AFB), whereas honeybee larvae show susceptibility against this pathogen only during the first 48 h of their life. It is known that midgut homogenate of adult honeybees as well as a homogenate of aged larvae exhibit strong anti-P. larvae activit...