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Fishery Bulletin 89(2). 1991 



Blind side creamy-white. Peritoneum unpigmented. 

 Pigmentation of outer surface of ocular-side opercle 

 usually same as that of body; occasionally with dusky 

 blotch on upper opercular lobe due to pigment on in- 

 ner lining of ocular-side opercle showing through to 

 outer surface. Inner lining of opercle and isthmus on 

 ocular side usually dusky; some specimens with dark- 

 brown pigmentation on inner opercular lining; inner 

 opercle and isthmus on blind side usually unpigmented 

 or occasionally with small patch of pepper-dot pigmen- 

 tation on ventral margin. Usually with slight pigment 

 band on ocular-side upper lip and diffuse pattern of 

 melanophores on lower lip. 



Dorsal and anal fins dusky; fin rays streaked with 

 pigment darker brown than that of connecting mem- 

 brane; sometimes with alternating series of darker- 

 pigmented rays (usually 2-3 in succession) separated 

 by about 4-5 successive, lighter-pigmented rays. Basal 

 half (scale-covered) of caudal fin dark-brown; fin rays 

 in distal half streaked with pigment. 



Size and sexual maturation (Fig. 2) Symphurus pla- 

 gusia is a medium-sized tonguefish. The largest of five 

 males examined was 130mm SL; the largest of 23 

 females was only slightly smaller (127mm SL). 



Sexual maturity occurs at a relatively large body size 

 in this species. All females larger than 80 mm SL were 

 mature. All but one female (79.3 mmSL) smaller than 

 80 mm SL were immature, with gonads undergoing 

 elongation without ripening ova or with ovaries bare- 

 ly elongating. 



Geographic distribution (Fig. 3) Widely distributed 

 in shallow waters of the tropical western Atlantic. In 

 the northern portion of its distribution, this species 

 occurs in Puerto Rico, Haiti, and Hispaniola, but is 

 unknown from the Bahamas (Bohlke and Chaplin 1968). 

 Along the continental margin of Central America, S. 

 plagusia has been collected at Belize, Nicaragua, Costa 

 Rica, and Panama, while further south it ranges along 

 the Atlantic coast of Colombia and coastal regions in 



Surinam, Tobago, and Brazil at least as far south as 

 Rio de Janeiro. 



Bathymetric distribution Symphurus plagusia is a 

 shallow-water species (1-51 m) most commonly in- 

 habiting depths between the shoreline and 10 m (Table 

 11), where (20/25, 80%) of specimens examined were 

 taken. All life-history stages occur in these shallow 

 areas and only occasionally were individuals taken at 

 deeper locations (one specimen at 51m, three speci- 

 mens at 40 m, and one specimen at 37 m). 



Ecology Little is known concerning the biology of S. 

 plagusia. Its general rarity in collections indicates that 

 it occurs in rarely-sampled habitats. 



Remarks The earliest description of a western Atlan- 

 tic, shallow-water, 12-caudal-rayed tonguefish is of 

 a specimen collected in Jamaica that Browne first 

 described (1756) as Plagusia and later (1789) as Pleu- 

 ronectes plagusia. He described this specimen as a 

 small sinistral flatfish with dorsal, anal, and caudal fins 

 united (tail ending in sharp point), lacking pectoral fins 

 and lateral lines. His description was clearly that of a 

 tonguefish, but he provided no figure or diagnostic 

 characters to unequivocally identify his specimen. 

 Browne's names were later suppressed under the 

 plenary powers for nomenclatorial purposes in Opinion 

 89 of the Commission for Zoological Nomenclature (see 

 Hemming and Noakes 1958). 



In 1801, Schneider first made Browne's tonguefish 

 Pleuronectes plagusia available as a binomial. Schnei- 

 der's Pleuronectes plagusia was based entirely on the 

 description of the tonguefish from Jamaica in Browne's 

 works (1756, 1789). The description by Schneider (in 

 Bloch and Schneider 1801) is identical to that provided 

 by Browne and, in addition, all indications are that 

 Schneider did not directly examine any specimens of 

 this species. Dr. H.-J. Paepke (Mus. fur Naturkunde 

 der Humboldt-Universitat zu Berlin, Zoologisches 

 Mus., Invalidenstrasse 43, Berlin DDR 1040, pers. 



