Showing papers on "Uca pugilator published in 2001"

Limb Regeneration in the Fiddler Crab, Uca pugilator: Hormonal and Growth Factor Control1

Abstract: This paper summarizes recent work on various aspects of hormonal control of regeneration in the crustacean, Uca pugilator. Hormonal control in this crab is effected by means of the crustactean steroid hormones, the ecdysteroids. New evidence is presented supporting a role for the retinoid hormones, all-trans retinoic acid and 9-cis retinoic acid, in the control of regeneration in these animals. The possible role of fibroblast growth factors in organization of the limb blastema is explored and the similarities between vertebrate and invertebrate control of regeneration are discussed.

Effect of melatonin on hemolymph glucose and lactate levels in the fiddler crab Uca pugilator

Abstract: Melatonin was injected into intact and eyestalk-ablated fiddler crabs (Uca pugilator), and its effects on hemolymph glucose and lactate levels were studied. In intact crabs, glucose and lactate levels cycled simultaneously, with peaks occurring during early and late photophase. Melatonin caused a shift in the glucose and lactate cycles, with only one peak occurring closer to mid-photophase. In eyestalk-ablated animals, the glucose rhythmicity was lost; lactate cycled, but levels were significantly lower than in intact animals. Melatonin caused a delayed hyperglycemia in eyestalk-ablated animals, with concurrent but much lower increases in lactate. Overall, melatonin demonstrated delayed hyperglycemic effects that do not appear to be mediated solely via eyestalk factors such as crustacean hyperglycemic hormone (CHH), though involvement of the eyestalks cannot be ruled out. An influence on extra-eyestalk CHH secretion is a potential mechanism of melatonin activity.