eye diameter
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MAUSAM ◽  
2021 ◽  
Vol 50 (2) ◽  
pp. 129-134
Author(s):  
R. V. SHARMA

Radar is a very powerful tool in determining the position, speed and direction of movement, horizontal and vertical extent of the cyclone. Besides, the radar observations can also be expected to provide more vital information on the shape, size and behaviour of the eye of a cyclone. These features are very important input information for cyclone forecasting, especially in assessing the intensity of the cyclone. An effort has been made here to document the above features of a cyclone that struck the east Godavari coast in November 1996.   The cyclone formed over central Bay of Bengal in the afternoon of 5 November 1996 and intensified into a severe cyclonic storm with a core of hurricane winds next day. The cyclone was tracked by Cyclone Detection Radar (CDR) Visakhapatnam from the initial stage of its formation till it crossed the coast near Kakinada. In this paper, the radar track of the cyclone over sea, along with the size. shape and behaviour of the eye as observed on radar have been discussed. The variation of other parameters like eyewall width, radius of maximum reflectivity and wall cloud height and relationship between eyewall width and eye diameter have also been discussed.


2021 ◽  
Vol 912 (1) ◽  
pp. 012030
Author(s):  
Desrita ◽  
R Rambey ◽  
R Saleh ◽  
I E Susetya ◽  
E Yusni ◽  
...  

Abstract Sucker barb fish is one of the potential of fish resources in Tasik river. This study aimed to determine the morphometric and meristic characteristics of the growth of sucker barb fish in the Tasik River. The method used in this study is a survey method using the fishing net and gillnet with mesh size 1,5 inches. The nets are placed in the afternoon, then lifted in the morning. This is done 3 times with a span of 2 weeks in the three research stations. The number of samples collected were 135 fish. The morphometric characteristics of sucker barb fish are bodyweight (BT) ranging from 9-85 g, total length (PT) ranging from 100-230 mm, standard length (PS) ranging from 75-176 mm, head length (PK) of 20-42 mm, snout length (PM) of 30 mm, the height of dorsal fin (TSP) of 40 mm, length of the base of dorsal fin (PPSP) of 15-30 mm, eye diameter (DM) of 10 mm, caudal peduncle (TBE) of 8-22 mm, body height (TB) of 17-40 mm, pectoral fin length (PSD) of 30 mm and pelvic fin length (PSP) of 25 mm. Meristic characteristics are the characteristics of counting the scales and fins of sucker barb fish. The number of scales in the lateral lines (LL) is 35-38, the body coiled scales (SMB) are 6, the scales around the pectoral fin (PF) P 10-14, anal fin (AF) A 8 and caudal fin (CF) C 18. The growth pattern of sucker barb fish in the Tasik River is allometric negative


Author(s):  
Le Trung Hieu ◽  
Dinh Minh Quang ◽  
Hua Van U ◽  
Nguyen Huu Duc Ton

This study provided data on morphological variation in Periophthalmus chrysospilos. The study was carried out in four provinces from Tra Vinh to Soc Trang, Bac Lieu and Ca Mau. Fish samples were collected by hand-catching over 12 months from April 2020 to March 2021. Analysed results of a collection of 1,031 individuals (508 females and 523 males) showed that the total length (TL) and weight (W) of the female Periophthalmus chrysospilos were higher than that of the male, higher in the wet season than in the dry season and gradually increased from Tra Vinh to Ca Mau. Besides, the total length and weight of fish were also influenced by the interaction of season ´ site and gender ´ site. In addition, the morphological variation of this species such as eye diameter (ED), eye distance (DE), body height (BD), head length (HL) and taxonomic ratios such as HL/TL, BD/TL, ED/HL, DE/HL was gender, seasonal fluctuations and study sites. These morphological variations and ratios were also influenced by interactions season ´ site interactions. The findings contributed further information to fish identification and the ecological adaptation understanding of this species.


Zootaxa ◽  
2021 ◽  
Vol 5027 (2) ◽  
pp. 254-268
Author(s):  
AKSHAY KHANDEKAR ◽  
DIKANSH S. PARMAR ◽  
NITIN SAWANT ◽  
ISHAN AGARWAL

We describe a distinct new species of the genus Hemiphyllodactylus based on three specimens collected from semi-urban areas in Goa state of India. The new species can be easily distinguished from all peninsular Indian congeners by its small body size (SVL up to 32.4 mm), having 16–18 dorsal scales and 13 or 14 ventral scales at mid-body contained within one longitudinal eye diameter, nine or ten precloacal pores separated by 1–5 poreless scales from a series of 10–12 femoral pores on each thigh in males, lamellar formula of manus 2222 and of pes 2323 & 2333, as well as subtle colour pattern differences. Mitochondrial sequence divergence confirms the distinctiveness of the new species, which is not closely allied to either the South Indian or Eastern Ghats clades of Indian Hemiphyllodactylus and appears to be a member of a third Indian Hemiphyllodactylus clade. Hemiphyllodactylus goaensis sp. nov. is the first member of the genus to be described from the northern Western Ghats region as well as Goa state, and also only the second Indian Hemiphyllodactylus known from < 100 m asl. Hemiphyllodactylus goaensis sp. nov. extends the known distribution of the genus in western India ~ 560 km north in aerial distance and highlights that the genus is more widely distributed than previously thought and most likely contains numerous undescribed species. We also provide final museum numbers for type specimens of H. arakuensis and the holotype of H. kolliensis.  


Zootaxa ◽  
2021 ◽  
Vol 5016 (2) ◽  
pp. 271-282
Author(s):  
HSUAN-CHING HO ◽  
CHI-NGAI TANG ◽  
TAH-WEI CHU

A new species of Coloconger is described from a large female collected off eastern Taiwan. It can be distinguished from congeners by having a large black blotch on rear portion of tail; posterior end of tail white; and combination of characters: head small 15.7% TL; 4 supratemporal pores, middle 2 in pair; 7 supraorbital pores, 2 pores over posterior nostril; 12 or 14 infraorbital pores; 14 preoperculomandibular pores; 226 dorsal-fin rays and 122 anal-fin rays; preanal vertebrae 77 and total vertebrae 145; rictus through a vertical of posterior margin of pupil; snout shorter than eye diameter; distance between origins of pectoral and dorsal fins 69.4% pectoral-fin length; and body brownish gray dorsally, light gray ventrally, and dorsal fin dark gray. Data and variations of Coloconger japonicus found in Taiwan are provided and discussed.  


Zootaxa ◽  
2021 ◽  
Vol 4996 (2) ◽  
pp. 322-330
Author(s):  
HEOK HEE NG ◽  
MAURICE KOTTELAT

Pseudobagarius eustictus, new species, is described from the Nam Heung drainage (a tributary of the Mekong River) in northern Laos. It is distinguished from congeners in having a unique combination of the following characters: a weakly-produced snout in which the upper jaw extends only slightly beyond the margin of the lower jaw when viewed ventrally, 3 tubercles on the posterior margin of the pectoral spine, eye diameter 8% HL, head width 24.1% SL, dark yellow dorsal and lateral surfaces of the head, pectoral spine lacking elongate extensions, pectoral fin reaching the pelvic-fin base when adpressed against the body, dorsolateral surfaces of body without longitudinal series of prominent tubercles, body depth at anus 13.7% SL, length of adipose-fin base 17.7% SL, caudal-peduncle depth 7.0% SL, and 33 vertebrae.  


2021 ◽  
Author(s):  
Chao Shen ◽  
Xijing Zhao ◽  
Chengyong He ◽  
Zhenghong Zuo

Abstract Propylene glycol (PG) is widely used in the foods, pharmaceuticals, oil industry, animal feed, cosmetics and other industries. Because of the existence of a chiral carbon center, PG forms R (Rectus)- and S (Sinister)-enantiomers. Currently, the toxicity study of its R-, S-enantiomers is still very scarce. In this study, we have assessed the developmental toxicity and neurotoxicity of the R-, S-, and RS-PG enantiomers in zebrafish larvae. We found that exposure to R-, S-, and RS-PG enantiomers did not significantly affect the basic developmental endpoints of embryos or larvae (i.e., embryonic movement, hatching, mortality, malformation, heartbeat, body length), indicating that R-, S-, and RS-PG exposures did not exhibit the basic developmental toxicity in zebrafish larvae. The toxicity of the three enantiomers was lower than that of ethanol, and there was no significant difference between them. However, R-, S-, and RS-PG exposures with high doses could significantly change the eye diameter and the locomotor activity of larval zebrafish, indicating that R-, S-, and RS-PG enantiomers of high doses can potentially exhibit the neurotoxicity and ocular developmental toxicity in zebrafish larvae. Therefore, the potential neurotoxicity and ocular developmental toxicity of R-, S-, and RS-PG enantiomers for infants and toddlers should be considered.


Zootaxa ◽  
2021 ◽  
Vol 4980 (1) ◽  
pp. 45-63
Author(s):  
MARCELO KOVAČIĆ ◽  
HAMID REZA ESMAEILI ◽  
FATAH ZAREI ◽  
KEYVAN ABBASI ◽  
ULRICH K. SCHLIEWEN

A new gobiid species, Benthophilus persicus sp. nov., is described from the southern Caspian Sea, Iran. The new species is diagnosed by the following character states: dermal fold on cheek well-developed, large, rectangular; chin barbel 1/3–2/3 of eye diameter; maximum body width 15.1–22.9% of standard length; mouth width, 36.3–55.8% of head length; second dorsal fin I+7–8; origin of anal fin in front of vertical through origin of second dorsal fin; dermal tubercles present on body, clearly larger than granules, with two posterior rows of spinules forming an acute angle, always less than right angle; dorsal row of tubercles complete, 22–29; ventral row of tubercles 22–25; ventrolateral row of tubercles absent; tubercles not present on temporal and occipital head regions; granules not present on flanks; transversal suborbital row 6i below posterior end of row b; anterior interorbital transversal row pa with one or two papillae and anterior interorbital transversal papilla row pp with two or three papillae; body with 20–22 transversal ltm rows starting anteriorly behind pectoral axilla and alternating anteriorly with three longitudinal llm rows. 


2021 ◽  
Vol 288 (1950) ◽  
Author(s):  
Ian J. Ausprey

The role of light in structuring the ecological niche remains a frontier in understanding how vertebrate communities assemble and respond to global change. For birds, eyes represent the primary external anatomical structure specifically evolved to interpret light, yet eye morphology remains understudied compared to movement and dietary traits. Here, I use Stanley Ritland's unpublished measurements of transverse eye diameter from preserved specimens to explore the ecological and phylogenetic drivers of eye morphology for a third of terrestrial avian diversity ( N = 2777 species). Species with larger eyes specialized in darker understory and forested habitats, foraging manoeuvres and prey items requiring long-distance optical resolution and were more likely to occur in tropical latitudes. When compared to dietary and movement traits, eye size was a top predictor for habitat, foraging manoeuvre, diet and latitude, adding 8–28% more explanatory power. Eye size was phylogenetically conserved ( λ = 0.90), with phylogeny explaining 61% of eye size variation. I suggest that light has contributed to the evolution and assembly of global vertebrate communities and that eye size provides a useful predictor to assess community response to global change.


Zootaxa ◽  
2021 ◽  
Vol 4926 (1) ◽  
pp. 134-146
Author(s):  
HEOK HEE NG ◽  
MAURICE KOTTELAT

Bagarius vegrandis, new species, is described from the Chao Phraya and Mekong river drainages. It differs from congeners in having a small maximum body size (to 220 mm SL vs. 520–1400 mm SL) and the adipose-fin origin markedly posterior to (vs. at vertical through or very slightly posterior to) the anal-fin origin. It further differs from congeners in having the following unique combination of characters: ovoid unculiferous plaques on dorsal surface of head, lateral margin of frontal not significantly deflected dorsally, eye diameter 11–15% HL, interorbital distance 23–28% HL, head width 18.3–22.3% SL, head depth 11.1–14.1% SL, filamentous extensions to first pectoral-fin element reaching to anus, dorsal spine width 10.6–13.9 times in its length, body depth at anus 8.7–12.0% SL, neural spines of the 4–6 vertebrae immediately anterior to adipose fin distally flattened but not forming series of prominent bumps along dorsal midline, length of adipose-fin base 10.8–13.0% SL, caudal-peduncle length 19.0–22.4% SL, caudal-peduncle depth 3.2–4.2% SL, 19–20 preanal vertebrae, and 39–40 total vertebrae. Bagarius bagarius (Hamilton, 1822) is demonstrated to be a species restricted to the Indian subcontinent (with Bagrus yarrelli Sykes, 1839, Pimelodus platespogon Valenciennes, in Jacquemont, 1839 and Pimelodus carnaticus Jerdon, 1849 as junior subjective synonyms) and Bagarius lica Volz, 1903 resurrected from synonymy with B. yarrelli as a valid species from Southeast Asia. 


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