stridulans (Jackson (Chong and Developmental et al., Sasekumar, stage Characters 1989) 1994) Egg diameter (mm) -- 0.697-0.729 Nauplius shape -- pandulate Third stage dorsomedian abdominal protozoea spines 5 3 First stage posterior ventral mysis serrations on the carapace absent absent Third stage statocyst
present absent mysis First stage scaphognathite setae postlarva in maxilla 20 21 scaphocerite spines on outer margine of antenna 1 2 thoracic sternal plate spines 2, 2, 0, 0, 0 -- M.
We determined whether each photographed individual was a veliger, pediveliger, or juvenile based on the presence or absence of the velum, foot, statocyst
, and mantle.
Serrate setae were found only on the statocysts
, which appear during larval stage VII.
In two such instances, which were recorded in different sagittal plane slices tilted at 90[degrees], a bristle group on the lower side of the statocyst
suddenly flopped to the epithelial floor, towards the nearby ciliary dome, then straightened immediately, returning to its previous upright stance (Fig.
of ctenophores is a long-studied structure whose function is generally understood.
The ctenophore statocyst
exploits both motile and sensory functions of cilia (Tamm, 1982, 2014a, b).
The squid statocyst
and its sensory hair cells share many characteristics with vertebrate vestibular systems yet maintain intriguing morphological differences, despite the functional commonalities of the two systems (Dilly et al., 1975; Dilly, 1976; Stephens and Young, 1982).
The rhopalial touch plates and sensory pads may represent sensory components of statocyst
function in cubomedusae considering the tight placement of rhopalia in their rhopalial niches (which can totally enclose the rhopalia in some species) and the constant movement of the tissues during swimming.
Additionally, GABA reduces the resting electrical activity of the squid statocyst
(Tu and Budelmann, 2000).
Four perradial and four interradial rhopalia in deep pits, surrounded by two thickened lips in subumbrella, [approximately equal to]27% of marginal bell radius (= 8.19 cm) from bell margin; rhopaliar pit depth [approximately equal to]1 mm, rhopaliar pit width [approximately equal to] 4.2 mm, rhopaliar pit length [approximately equal to] 6.9 mm; rhopalium has simple statocyst
without obvious ocellus (Fig.
vulgaris, they have been found in both the statocyst
and brain (Budelmann and Thies, 1977).
The role of [Ca.sup.2+] in deflection-induced excitation of motile, mechanoresponsive balancer cilia in the ctenophore statocyst