Scanning electron microscope study of the development of mandibular structure and the molar surface morphology of Branchinella maduraiensis and Streptocephalus dichotomus (Crustacea, Anostraca)

2006 ◽  
Vol 84 (9) ◽  
pp. 1248-1262 ◽  
Author(s):  
Chinavenmeni S. Velu ◽  
Natesan Munuswamy
Keyword(s):  
Surface Morphology ◽  
Developmental Stages ◽  
Gradual Transition ◽  
Mandibular Movement ◽  
Scanning Electron Microscope Study ◽  
Larval Stages ◽  
Ephemeral Pools ◽  
Molar Morphology ◽  
Further Development ◽  
Scanning Electron

In the present study, the molar surface morphology of Streptocephalus dichotomus Baird, 1860 and Branchinella maduraiensis Raj, 1961 is analyzed and correlated with the distribution of these species in ephemeral pools. The larval stages of S. dichotomus are characterized by scanning electron microscopy in relation to their feeding physiology, which shows their morphological complexity during developmental stages. The larval mandible consists of a coxa with a three-segmented palp, and further development leads to its gradual transition into the adult mandible. Muscles involved in mandibular movement exhibit rotatory and counter-rotatory movement, which enhances the grinding of food materials. Analysis of the molar surface morphology of B. maduraiensis and S. dichotomus reveals that the mandibles are asymmetrical. Detailed analysis of the topography of the molar illustrates specific structural differences between the species. Gut content analysis also perfectly matches the molar morphology of these species, confirming that B. maduraiensis handles zooplankton more preferentially than S. dichotomus. Our investigation of these fairy shrimps provides information on their molar surface morphology and feeding biology, which increases the understanding of their coexistence.

Swimming speeds of the larval stages of the parasitic barnacle, Heterosaccus lunatus (Crustacea: Cirripedia: Rhizocephala)

2004 ◽  
Vol 84 (4) ◽  
pp. 737-742 ◽  
Author(s):  
Graham Walker
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Developmental Stages ◽  
Larval Form ◽  
Larval Stages ◽  
Moreton Bay ◽  
Portunid Crab ◽  
Lecithotrophic Development ◽  
Scanning Electron

Heterosaccus lunatus parasitizes the portunid crab, Charybdis callianassa, in Moreton Bay, Queensland, Australia. Larval broods, released during July and August (males only), were allowed to develop through to cyprids (lecithotrophic development). Speeds of all the developmental stages—nauplius I to nauplius IV and the cyprids were measured by timing continuously swimming larvae over 5 mm distances under a microscope. The absolute speeds of the naupliar stages were similar (3–4 mm s−1), but the cyprids were significantly faster at ≈10 mm s−1. These speeds were compared with published speeds of cirripede and copepod nauplii and other cirripede cyprids. Relative speeds (body lengths s−1) showed surprising parity, which for the cyprids probably reflects the similar efficiency of the fusiform shape and thoracopod propulsion for all sizes of this highly specialized larval form. The lecithotrophic H. lunatus nauplii have rather minimalistic appendages (compared with planktotrophic nauplii) which were examined at the light microscope and scanning electron microscope levels. The natatory setae were found to be plumo-denticulate.

scholarly journals Mucosal surface morphology of the toad urinary bladder. Scanning electron microscope study of the natriferic and hydro-osmotic response to vasopressin

1978 ◽  
Vol 77 (2) ◽  
pp. 598-610 ◽  
Author(s):  
JW Mills ◽  
LE Malick
Keyword(s):  
Urinary Bladder ◽  
Surface Morphology ◽  
Water Flux ◽  
Granular Cell ◽  
Mucosal Surface ◽  
Toad Urinary Bladder ◽  
Osmotic Gradient ◽  
Scanning Electron Microscope Study ◽  
Osmotic Response ◽  
Scanning Electron

The mucosal cell surface of the toad urinary bladder was examined by scanning electron microscopy, and changes in the structure of the surface of the granular cell were correlated with specific physiological responses to vasopressin. Survey views of the mucosal surface demonstrated that there was no consistent repeating anatomical relationship between the granular cell and the mitochondria-rich cell that would support the concept of cooperativeness in the response to vasopressin. During base-line states of Na+-transport and water flux, the microvilli on the mucosal surface of the granular cell are arranged in a ridge-like network with occasional individual projections. When water flux is increased by exposing the tissue to vasopressin, in the presence of an osmotic gradient across the tissue the microvilli on the granular cell lose the ridge structure and appear, predominantly, as individual projection. Variability-of this appearance points out the necessity of examining large areas and many samples before the significance of any morphological change can be assessed. Blocking the simultaneously occurring natriferic response of the toad urinary bladder with 10(-2)M ouabain does not prevent these changes in the microvilli. When the hydro-osmotic response is blocked by eliminating the osmotic gradient, the granular cell shows no consistent change in mucosal surface morphology even when fixed at the height of the natriferic response. The mitochondria-rich and mucous cells did not show any change in morphology throughout these studies. We conclude that the changes in the mucosal surface morphology of the toad bladder seen after exposure to vasopressin are a result of the increased water flux that occurs when an osmotic gradient exists across the tissue, and are not related to the natriferic response or any specific alteration in the membrane properties.

External Morphology, Oral Structure and Feeding Behaviour of Kaloula pulchra TADPOLES Gray, 1831 (Amphibia: Anura: Microhylidae)

2017 ◽  
Vol 5 (2) ◽  
pp. 97-103
Author(s):  
H.T. Lalremsanga ◽  
◽  
Saipari Sailo ◽  
R.N.K. Hooroo ◽  
◽  
...  
Keyword(s):  
Feeding Behaviour ◽  
Developmental Stages ◽  
Developmental Rate ◽  
External Morphology ◽  
Scanning Electron Micrographs ◽  
Plant Materials ◽  
Larval Stages ◽  
The Family ◽  
The Common ◽  
Scanning Electron

The external morphology and oral structure of various developmental stages in relation to feeding behaviour of Kaloula pulchra Gray, 1831 (Amphibia: Microhylidae) were studied with the help of light microscopyand scanning electron microscopy (SEM). Light and scanning electron micrographs revealed that the oral apparatus at different larval stages are devoid of jaw sheath, labial teeth and keratodonts, instead they have a terminally-oriented, as opposed to an antero-ventrally oriented mouth (umbelliform) known as semicircular labial flap. These features illustrate that the tadpoles within the family Microhylidae could be attributed to assistance in clarifying a certain taxonomic treatment in this family. Observation on the present results showed that tadpoles of Kaloula pulchra are nektonic suspension feeders and started feeding from stage 25 onwards. During the early stages of feeding, they feed mostly on detritus and plant materials and during the later stages of feeding they consumed both phytoplankton and zooplankton. At stage 42, the tadpole stopped feeding and the mouth part is degenerated and gradually transformed in to adult mouth. The preference of Bacillariophyceae and Cyanophyceae in the food habits of this explosive breeding species may be due to the common available food items in their microhabitat that enhanced the faster developmental rate within a short duration.

Sign in / Sign up

Export Citation Format

Share Document