scholarly journals Description of a Small-headed Gnathiid Isopod (Crustacea), Gnathia capitellum sp. nov., from Coastal Japan

2021 ◽  
Vol 26 (2) ◽  
pp. 207-216
Author(s):  
Yuzo Ota ◽  
Hisanori Kohtsuka ◽  
Katsuhiko Tanaka
Keyword(s):  
Gnathiid Isopod

scholarly journals New and little-known gnathiid isopod crustaceans (Cymothoida) from the northern Great Barrier Reef and the Coral Sea

Zootaxa ◽  
2012 ◽  
Vol 3380 (1) ◽  
pp. 1 ◽  
Author(s):  
JÖRUNDUR SVAVARSSON ◽  
NIEL L. BRUCE
Keyword(s):  
New Species ◽  
Great Barrier Reef ◽  
Barrier Reef ◽  
Island Region ◽  
Coral Sea ◽  
Lizard Island ◽  
Island Group ◽  
Gnathiid Isopod

Ten species of Gnathiidae (Crustacea, Isopoda, Cymothoida) including six new species, are reported from Lizard Islandand nearby reefs, northern Great Barrier Reef and reefs of the Coral Sea (Chesterfield Reefs, Mellish Reef and MarionReef): Gnathia wistari sp. nov. (Lizard Island region and Capricorn Group, southern Great Barrier Reef), Gnathia coral-maris sp. nov. (Mellish Reef), Gnathia varanus sp. nov. (Lizard Island group), Gnathia marionis sp. nov. (Marion Reef),Gnathia hamletgast sp. nov. (Chesterfield Reefs) and Elaphognathia australis sp. nov. (Chesterfield Reefs). New locali-ties are reported for four other species: Gnathia aureamaculosa Ferreira and Smit, 2009 and Gnathia masca Farquharsonand Smit, 2012 from Lizard Island and nearby reefs; Gnathia falcipenis Holdich and Harrison, 1980 and Gnathia variobranchia Holdich and Harrison, 1980 from Lizard Island, Wistari Reef, Heron Island and Chesterfields Reefs.

scholarly journals Seasonal fluctuations of the sponge-dwelling gnathiid isopod Elaphognathia aff. cornigera

2008 ◽  
Vol 37 (0) ◽  
pp. 14-25 ◽  
Author(s):  
Yuzo Ota ◽  
Katsuhiko Tanaka ◽  
Euichi Hirose
Keyword(s):  
Seasonal Fluctuations ◽  
Gnathiid Isopod

Mass Transfer Performance of a Marine Zooplankton Olfactometer

2021 ◽  
Vol 143 (11) ◽  
Author(s):  
Ahmed A. Alkhafaji ◽  
Osama M. Selim ◽  
Ryoichi S. Amano ◽  
J. R. Strickler ◽  
P. Hinow ◽  
...  
Keyword(s):  
Host Finding ◽  
Chemical Concentration ◽  
Concentration Gradients ◽  
3 Dimensional ◽  
Marine Zooplankton ◽  
Chemical Gradients ◽  
Fluid Physics ◽  
Flow Domain ◽  
Chemical Distribution ◽  
Gnathiid Isopod

Abstract By adopting different methods to the inlet of a zooplankton olfactometer, the current study investigates the effect of the energy of chemical flow on the Gnathiid isopod crustaceans predicted behavior. These are mobile external parasites of fishes that have a significant impact on the health of their hosts. They rely at least in part on olfactory cues to find the host fish. To better understand host-finding dynamics in these parasites, a study was conducted with the simulations as a blueprint for developing a 3-dimensional test apparatus similar to what has been used for studying olfactory orientation in insects. The simulated olfactometer has four legs, each leg forming an inlet where fluids are introduced into the flow domain. There is one outlet at the center of the device. A mixture of water and chemicals is presented by applying a multi-component system. The shear and chemical concentration distribution were conducted to see how fluid physics plays a role in creating a chemical landscape. Computational results show distinct regions separated by high chemical concentration gradients when introducing chemicals from one leg. Changing the fluid inflow from one common inlet to three inlets shows that the chemical distribution exhibits steeper gradients than the typical inlet case, depicting that the gradual chemical concentrations can drive the animal toward the target faster. The best behavior that gives higher chemical gradients is obtained through the study when using three sub-inlets and Schmidt number between 3 and 10.

The gills of the coelacanth, Latimeria chalumnae , a study in relation to body size

1995 ◽  
Vol 347 (1322) ◽  
pp. 427-438 ◽  
Keyword(s):  
Electron Microscopy ◽  
Weighted Average ◽  
Mass Range ◽  
Length Frequency ◽  
Latimeria Chalumnae ◽  
Transmission Electron ◽  
Life Habits ◽  
Low Mass ◽  
Gill Lamellae ◽  
Gnathiid Isopod

Measurements of the surface area of the gill lamellae of specimens of the coelacanth, Latimeria chalumnae have been made. This involved measurement of total filament length, frequency of lamellae along the filaments and the weighted average bilateral area of a single lamella. Regression analyses of these parameters which combine to give total area were made for the mass range 434 g—80 kg. Results show that the slope is close to 0.81 which is similar to that of many other fishes. However, the intercept value is exceptionally low and confirms the low mass-specific measurements made on two 10 kg specimens in 1972. Material from a recently caught specimen has been used to extend previous transmission electron microscopy by the use of scanning electron microscopy. The surface of epithelial cells on lamellae and filaments is covered in microvilli and microridges with transitional zones. The appearance of microridges suggests that they may have arisen by coalescence of microvilli. Ventilatory movements of the mouth and operculum (three to four per minute) have been observed using videorecordings of resting specimens in caves. Specimens of the larval stage of a gnathiid isopod parasite were found but only on one of the nine sets of gills that were examined. It is concluded that this more extended study of gill morphometrics of Latimeria confirms predictions made from earlier comparative studies regarding the life habits of this fish which have also been confirmed by direct observation using submersibles.

Occurrence of praniza larvae of a gnathiid (Isopoda, Gnathiidae) on wild-caught orange-spotted grouper, Epinephelus coioides (Hamilton, 1822) (Perciformes, Serranidae), in Lingayen Gulf, Philippines

Crustaceana ◽  
2017 ◽  
Vol 90 (1) ◽  
pp. 101-110 ◽  
Author(s):  
Erlinda R. Cruz-Lacierda ◽  
Kazuya Nagasawa
Keyword(s):  
New Record ◽  
The Philippines ◽  
Epinephelus Coioides ◽  
Mean Intensity ◽  
Gill Filaments ◽  
Branchial Cavity ◽  
Gnathiid Isopod

Praniza larvae of a gnathiid isopod were retrieved from the gills and branchial cavity of wild-caught orange-spotted grouper, Epinephelus coioides (Hamilton, 1822) (Perciformes, Serranidae) in Lingayen Gulf, Philippines. The prevalence and mean intensity of the praniza larvae were 82.3% and 2.2 on the gill filaments and 23.5% and 2.5 in the branchial cavity, respectively. The praniza larva is described and illustrated as there has been no work on the morphology of the parasite in the country where it was collected, to date. This report involves a new record for larval gnathiid infection on E. coioides in the Philippines.

Size-related mortality due to gnathiid isopod micropredation correlates with settlement size in coral reef fishes

Coral Reefs ◽  
2017 ◽  
Vol 36 (2) ◽  
pp. 549-559 ◽  
Author(s):  
A. S. Grutter ◽  
S. P. Blomberg ◽  
B. Fargher ◽  
A. M. Kuris ◽  
M. I. McCormick ◽  
...  
Keyword(s):  
Coral Reef ◽  
Reef Fishes ◽  
Coral Reef Fishes ◽  
Settlement Size ◽  
Gnathiid Isopod ◽  
Related Mortality

New gnathiid isopod crustaceans (Cymothoida) from Heron Island and Wistari Reef, southern Great Barrier Reef

Zootaxa ◽  
2019 ◽  
Vol 4609 (1) ◽  
pp. 31 ◽  
Author(s):  
JÖRUNDUR SVAVARSSON ◽  
NIEL L. BRUCE
Keyword(s):  
New Species ◽  
Great Barrier Reef ◽  
New Records ◽  
Barrier Reef ◽  
First Time ◽  
Gnathiid Isopod ◽  
Eleven Species

Eleven species including six new species of Gnathiidae (Crustacea, Isopoda, Cymothoida) are reported from the Heron Island and Wistari Reef, Capricorn Group, southern Great Barrier Reef: Elaphognathia queenslandica sp. nov., Gnathia acrorudus sp. nov., Gnathia capricornica sp. nov., Gnathia carinodenta sp. nov., Gnathia formosa sp. nov. and Gnathia glaucostega sp. nov. Gnathia cornuta Holdich & Harrison, 1980 and Gnathia grutterae Ferreira, Smit & Davies, 2010 are for the first time reported from Heron Island and new records from Heron Island are provided for Gnathia biorbis Holdich & Harrison, 1980, Gnathia variobranchia Holdich & Harrison, 1980, and Gnathia wistari Svavarsson & Bruce, 2012. 

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