Polysteganus
Creators: name: Iwatsuki, Yukio
name: Heemstra, Phillip C.
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Perciformes
Sparidae
Polysteganus

description: Key to species of the Polysteganus from Indian Ocean   
 1a Large oval dark blotch on lateral line below 5th and 6th dorsal-fin spines in adults, but no dark blotch in 9 cm juveniles; body with 4 or 5 wide blue stripes (more than 1/3 width of black pupil diameter).............................. P. undulosus   
1b No dark blotch on lateral body; 7 or 8 narrow blue stripes (less than 1/4 width of black pupil diameter) or lines of blue spots on body if present....................................................................................... 2a  
 2a Greatest body depth at preopercle vertical edge; lower-limb gill-rakers 14–16......................... P. praeorbitalis   
2b Greatest body depth at pectoral-fin base; lower-limb gill-rakers 10–13............................................ 3  
 3a Body with 7 or 8 longitudinal blue stripes.......................................................... P. baissaci   
3b No longitudinal blue stripes or lines of blue spots on body..................................................... 4  
 4a Caudal fin weakly forked, nearly truncate if widely spread; distinct bony bulge before and above eye in specimens about 60 cm SL (bulge probably not apparent in juveniles); body reddish orange, without lines of blue spots........... P. mascarenensis   
4b Caudal fin forked; no strong bony bulge both before and above eye; body reddish yellow often with clear irregular lines of blue spots................................................................................................ 5  
 5a Scale rows between 5th dorsal fin spine and lateral line 4½; no irregular lines of blue spots; rear margin of membrane of branchiostegal rays yellow, plus yellow color on a few body scales just above upper pectoral-fin base..................................................................................................... Polysteganus cerasinus n. sp.   
5b Scale rows between the 5th dorsal fin spine and lateral line 5½–7½; no or 7–8 irregular lines of blue spots; rear margin of membrane of branchiostegal rays white (not yellow).......................................................... 6  
 6a Blue iridescence in each body scale on dorsal and lateral sides of body visible at some angles, and no irregular lines of blue spots; upper caudal-fin lobe yellow, lower red..................................... Polysteganus flavodorsalis n. sp.   
6b No blue iridescence in body scales on dorsal and lateral side; 7 or 8 irregular lines of blue spots on body, visible at some angles; both caudal-fin lobes with pink or red membranes...................................................... 7  
 7a Scale rows above lateral line 6½; pored lateral-line scales 51 or 52; 7 or 8 faint irregular lines of blue spots on body, visible at some angles; dorsal-fin rays reddish pink but with no bright yellow upper margin; canines large, both upper and lower canines on both jaws usually visible even when mouth closed; body deeper, 44–46% (mean 44%) of SL (Figs. 1 A, 2A)............................................................................................... P. coeruleopunctatus   
 7b Scale rows above lateral line 7½; pored lateral-line scales 53–55; 7 or 8 distinct irregular lines of blue spots on body (often present even in preserved specimens); dorsal-fin rays reddish pink or orangish red with bright yellow upper margin; canines somewhat smaller, generally only upper canines visible when mouth closed; body somewhat slender, 40–43% (mean 42%) of SL (Figs. 1 B, 2B)........................................................................ P. lineopunctatus
description: Published as part of Iwatsuki, Yukio & Heemstra, Phillip C., 2015, Redescriptions of Polysteganus coeruleopunctatus (Klunzinger 1870) and P. lineopunctatus (Boulenger 1903), with two new species from Western Indian Ocean, pp. 133-150 in Zootaxa 4059 (1) on page 147, DOI: 10.11646/zootaxa.4059.1.7, http://zenodo.org/record/246088