Munroe: Western Atlantic tonguefishes of the Symphurus plagusia complex 



271 



in breeding condition (collected with gravid females), 

 usually with more intense banding, dark-black fins, 

 dark-black spot on ocular-side opercle, and, additional- 

 ly, some specimens with irregularly-shaped, black pig- 

 ment patches on posterior one-half of blind side of body. 

 In contrast, mature females also with crossbands but 

 less conspicuous than in males and with posterior por- 

 tions of fins dark-brown but usually not black. Females 

 lack black pigment patches on blind side observed in 

 males. 



Ocular-surface background pigmentation ranging 

 from dark- to light-brown. Body usually with 5-9 

 (usually 5-7) well-developed, sharply contrasting, rela- 

 tively wide, dark-brown crossbands on head and trunk. 

 First two bands relatively consistent in position; first 

 crossing head immediately posterior to eyes; second 

 crossing body immediately behind opercular opening. 

 Crossbands on trunk variable in number and degree 

 of completeness, especially those between opercular 

 opening and point about equal to two-thirds of trunk 

 length. Males usually with 3-4 well-developed and 

 lesser number of incomplete bands along trunk. Two 

 posteriormost bands, just anterior to caudal fin base, 

 slightly arched and usually darker than others on body. 

 Blind side usually uniformly creamy-white; some 

 mature males with irregular patches of black pig- 

 ment on caudal one-third of blind side. Peritoneum 

 unpigmented. 



Outer surface of ocular-side opercle usually with 

 distinct, dark-brown or black spot on ventral margin 

 slightly forward of posterior margin of opercle. Oper- 

 cular spot ranging from almost spherical to dorso- 

 ventrally-elongate black blotch covering most of lower 

 opercle. Intensity of pigmentation in spot maximally 

 developed in sexually mature adults. Inner linings of 

 opercles and isthmus heavily pigmented on both sides 

 of body. Pigment band well developed on ocular-side 

 upper lip; ocular-side lower lip frequently spotted but 

 without well-defined band. 



Anterior dorsal and anal fin rays usually streaked 

 with brown pigment, more heavily pigmented than 

 connecting membranes. Fin rays and membranes of 

 dorsal and anal fins on posterior two-thirds of body 

 becoming increasingly darker posteriorly. Males with 

 posteriormost regions of fins almost uniformly black, 

 while in females, posterior portions of fins, although 

 darker than anterior regions, usually dark-brown and 

 not as intensively pigmented as in mature males. 



Size and sexual maturity Symphurus tessellatus is 

 one of the largest species in the genus and is the sec- 

 ond largest Atlantic tonguefish species after S. jenyn- 

 si Evermann and Kendall (Ginsburg 1951, Menezes and 

 Benvegnu 1976, Munroe 1987). Size-related life-history 

 information is based on data from 385 fish. Males and 



females attain nearly similar sizes, but females are 

 somewhat larger. The largest fish measured in this 

 study was a female of 220 mm SL; the largest male 

 measured 205 mm SL. 



There were 214 males, 155 females, and 16 immature 

 fish among material examined. There were 119 mature 

 females ranging in size from 104 to 220 mm SL (Fig. 

 2). Based on reproductive stages for females, sexual 

 maturity in this species occurs at sizes of 104-120 mm 

 SL, but usually larger than 115 mm SL. Most mature 

 females exceeded 140 mm SL, with only six smaller 

 than 125 mm SL and two smaller than 110 mm SL pres- 

 ent among fish examined. Twenty-six females of 

 49.5-119mm SL were immature. The smallest of these, 

 measuring 49.5 and 62.8mm SL, had ovaries that were 

 scarcely elongate. Other immature females, ranging 

 from 68.6 to 119mm SL, had only partially elongate 

 ovaries with no indications of developing ova. 



Geographic distribution (Fig. 3) A widespread trop- 

 ical species, ranging in the north from the larger Carib- 

 bean Islands such as Cuba, Hispaniola, and Puerto 

 Rico, southward to Uruguay. In the West Indies, adults 

 and juveniles have frequently been taken in abundance 

 at several localities, but the distribution of this species 

 appears limited by the location of soft silt and mud 

 sediments. These bottom types are more common on 

 the larger islands that support river and estuarine 

 habitats. The species has been taken at several inshore 

 locations in Puerto Rico, Cuba, and Haiti, and a large 

 number of adults were collected by the RV Oregon on 

 the shelf area southwest of Jamaica (Caldwell 1966). 

 Juveniles of this species have been taken from several 

 inshore areas in Jamaica as well. 



Along the continental margin it has been frequently 

 captured on muddy bottoms from Belize and Nicaragua 

 south to southern Brazil and Uruguay (ca. 37° S). In 

 the northern part of its range along Central America, 

 it has been collected as far north as Belize (17°12'N), 

 but thus far is unknown from the Yucatan Peninsula 

 or Campeche Bay. The absence of this species in the 

 Yucatan region may be explained by upwelling (Rivas 

 1968) or by changes in the sediments of this region. 

 The Yucatan Shelf is a broad limestone plateau with 

 a minimum of land-derived detrital sediments (Harding 

 1964, Topp and Hoff 1972). Instead of soft silt and mud 

 sediments typical of more southern locations, sedi- 

 ments on the inner shelf off the Yucatan Peninsula are 

 firmer, consisting of skeletal remains of various plank- 

 tonic and benthonic organisms, ooids, calcareous 

 pellets, lithic fragments, and grapestone aggregates. 

 This dramatic change from soft, mud substrates to 

 firmer sediments in the Yucatan region may account 

 for the absence of S. tessellatus in the waters off south- 

 ern Mexico. 



