Scaphognathite

Sca`phog´na`thite


n.1.(Zool.) A thin leafike appendage (the exopodite) of the second maxilla of decapod crustaceans. It serves as a pumping organ to draw the water through the gill cavity.
References in periodicals archive ?
Settlement was also recorded on the different part of the body like (hypobranchial gill rake, epibranchial gill rake, and scaphognathite) and the inner wall of the branchial chambers.
mulleri infestation causes increased heartbeat and scaphognathite fluttering rates, and severely weakens individuals with heavy infestations (Gannon & Wheatly 1994, Wu & Liu 1995).
Exopod (scaphognathite) margin with 4 plumose setae and a setose posterior stout process.
3) and may be linked to episodic reversal or cessation of scaphognathite (gill-pump) beating common in marine crustaceans (Taylor, 1982).
For example, an increase in scaphognathite beating rates, which increases ventilation at the gills and maintains hemolymph [Po.sub.2] levels, is a common physiological response in crustaceans (Taylor, 1982; McMahon, 2001).
Maxilla and first maxilliped with dense covering of setae-like structure formed by bacterial colony on ventral surfaces of scaphognathite and caridean lobe, respectively (Fig.
1F) Palp with 2, 1, 1, 2 setae; coxal endite with 6 distal setae; basal endite with 8 distal setae; broad scaphognathite with narrow posterior lobes having long naked setae.
Heart rate and scaphognathite beat frequency remain depressed after oxygen uptake returns to pretreatment levels (McGaw, 2006), which suggests that the observed short-term decrease in oxygen uptake is attributable to changes in activity level (McMahon et al., 1979) in the form of the observed closure behavior, independent of changes in ventilation and cardiac parameters.
The morphological characters of the first postlarva are 43 scaphognathite setae on the maxilla, three scaphocerite spines on the outer margin of antenna, and sternal plate spines: 2,2,0,1,1.
Certain elements of cardiovascular function specifically relating to the gill circulation were monitored; we quantified heart and scaphognathite function, and measured the hemolymph hydrostatic pressure change across the gill circulation in both saline- and Vibrio-injected crabs.
In decapods, maxilla 2 is responsible for ventilating the gills via the scaphognathite (gill bailer), and it therefore moves more-or-less constantly and in a stereotypical way (Garm and H0eg, 2001).
For each animal, the salinity in the recording chamber was gradually lowered from a starting value of 32 ppt to less than 20 ppt, at a rate of 1-2 ppt/min, while heart and scaphognathite rates were continuously recorded.