Paranthias GUICHENOT, 1868

Heemstra, P. C., 1991, A Taxonomic Revision Of The Eastern Atlantic Groupers (Pisces: Serranidae), Bol. Mus. Mun. Funchal 43 (226), pp. 5-71 : 55-57

Genus Paranthias GUICHENOT, 1868

Paranthias GUICHENOT, 1868: 87 (type species, Serranus fiırcifer VALENCIENNES, 1828 by monotypy).

Brachyrhinus GILL, 1863: 236 (type species, Serranus creolus VALENCIENNES, 1828 [= P. furcifer ] by monotypy; preoccupied by Brachyrhinus LATREILLE, 1802 ).

Creolus JORDAN & GILBERT, 1883: p. xxxvi (type species, Serranus fiırcifer VALENCIENNES by monotypy; listed in Table of Contents as if in Addenda, but replaced on page 973 by Paranthias GUICHENOT ).

Diagnosis: Body oblong, fusiform, dorsal and ventral profiles almost equally curved, the depth contained 2.7-3.4 times in standard length, the body width 1.8-2.5 times in the depth; head length 3.2-4.0 times in SL. Dorsal head profile convex; snout short, subequal to eye diameter (except in large adults); interorbital area flat or slightly convex; preorbital depth less than half eye diameter, contained 10- 14 times in head length; mouth small, the maxilla not reaching past vertical at centre of eye; preopercle subangular, with vertical limb and rear half of lower limb finely serrate; upper edge of operculum convex; anterior and posterior nostrils subequal.

Caudal fin distinctly forked, the middle rays less than half length of upper or lower caudal lobes, with 8 + 7 branched rays and 12- 13 + 11 -12 procurrent rays; dorsal fin with 9 spines and 17-21 rays, the fin origin posterior to vertical at upper end of pectoral-fin base; the interspinous membranes slightly indented;no dorsal fin spines no or rays elongated; base of spinous part shorter than base of soft-rayed part; soft dorsal fin margin rounded; anal fin with 3 spines and 8- 11 rays; anal fin margin straight; pectoral fins large, distinctly longer than pelvics, contained 0.9- 1.2 times in head length, the middle rays longest. Midlateral body scales ctenoid. Jaws with rudimentary canines; teeth present on palatines and in an oval patch on vomer; supramaxilla vestigal or absent; no knob or step on ventral edge of maxilla.

Supraneural bones 2, the second about tvvo-thirds length of first; dorsal and anal fins with 3 -5 trisegmental pterygiophores at rear end of fin; rear edge of first dorsal pterygiophore not excavated for tip of third neural spine; epipleural ribs on first 9 vertebrae.

Cranium short and wide, the least interorbital width more than half width at lateral ethmoids and twice width of vomer; frontals separated anteriorly by supraethmoid; well developed median crest on frontals, continuous with supraoccipital crest, but the frontal part of crest not visible in lateral view because interorbital area is recessed (concave dorsally); parasphenoid distinctly bent upwards anteriorly.

GEOGRAPHICAL DISTRIBUTION

Tropical and subtropical waters of the Atlantic and eastern Pacific oceans: In the eastern Atlantic, P. furcifer is known only from Ascension Island and islands in the Gulf of Guinea. In the western Atlantic, it is known from Bermuda, south Florida, Gulf of Mexico, Cuba, southern Bahamas, Caribbean to southern Brazil.

E. margin. M. fusca M. fusca M. rubra M. acuti Neotype Neotype n = 13 n = 7 n = 13

SL (mm.) 200 300 129-510 126-585 104-343 Body depth Head length Snout length 38 41 33 37 30-36 35-39 31-36 36-40 31 -39 37-42 11 11 10-13 9.2- 12 9.9- 12 Orbit diameter 6.6 5.3 4.5-7.8 4.9-6.2 5.1-8.9

Interorbital width 7.8 8.0 6.5-8.4 6.0-8.6 6.6-8.1 Preorbital depth Upper jaw length 3.9 4.0 2.7-4.7 2.9-4.6 2.8-4.1 19 17 16- 19 17-19 17-20 Maxilla width 4.8 4.3 3.8-5.0 4.1-5.1 4.4-5.8

Caudal peduncle deth 13.2 13 11-13 12- 14 13 -15

REMARKS

Paranthias is a unique genus of groupers that have a "small mouth [with upper jaw more protrusile than in other groupers], small teeth, numerous [long] gill rakers, fusiform body, and deeply forked caudal fin — all representing departures from the typical grouper morphology, and all specializations for feeding m mid-water on zooplankton" ( RANDALL, 1967). Paranthias feed mainly on small planktonic animals that are picked individually from the water, and their shortened snout (compared to other groupers), which facilitates close-range binocular vision, is thus another specialization for this type of plankton feeding. They are usually seen in feeding aggregations well above the reef, but they will retreat to the reef at the approach of danger. They are found in depths of 10-70 m.

The genus Paranthias comprises two valid species. ‘the distinction of the eastern Pacific species, P. colonus (VALENCIENNES, 1855) and P.furcifer is discussed by HEEMSTRA and RANDALL (in press).