Glandulocauda melanopleura (Ellis, 1911)

Menezes ¹, Naércio A. & Weitzman ², Stanley H., 2009, Systematics of the Neotropical fish subfamily Glandulocaudinae (Teleostei: Characiformes: Characidae), Neotropical Ichthyology 7 (3), pp. 295-370 : 310-316

Diagnosis. Glandulocauda melanopleura can be distinguished from all the other glandulocaudines except G. caerulea by having caudal rays 11 and 12 slightly decurved but not forming a caudal-fin ray pump. From G. caerulea it differs by possessing 20-24 branched anal-fin rays (15-18 in G. caerulea ), 13-16 horizontal scale rows from dorsal-fin origin to anal-fin origin (11-13 in G. caerulea ) and 37-42 lateral series scales (31-35 in G. caerulea ).

Description. Table 3 presents morphometrics of examined specimens. Description based on samples from near type locality treated statistically as one population sample other than where noted otherwise. Counts given second in brackets for type of Glandulocauda melanogenys . Body compressed, relatively deep, especially near dorsal-fin origin; body deepest along vertical at point between pelvic-fin and anal-fin origins. Predorsal body profile gently convex to tip of snout ( Figs. 11 and 12 ). Body profile somewhat elevated at dorsal-fin origin, arched in males, less so in females and juveniles. Dorsal profile of body relatively straight along dorsal-fin base to adipose fin. Body profile posterior to adipose fin concave dorsal to caudal peduncle. Dorsal-fin origin nearer to caudal-fin base than to snout tip. Ventral profile of body convex in adult males and females from anterior tip of lower jaw to origin of pelvic fins, convexity less pronounced in juveniles.Abdominal profile in adult males slightly concave between pelvic-fin and anal-fin origins; straight or slightly convex in juveniles and females. Body profile along anal-fin base in both sexes slightly concave to slightly convex at region of anterior lobe of anal fin; more or less straight along remainder of fin. Ventral profile of caudal peduncle anterior to procurrent rays more or less straight or slightly concave.

Lower jaw protruding, extending slightly anterior to upper jaw. Lower jaw of fully adult males thick and heavy compared to that of females and juveniles. Mouth angled posteroventrally. Maxilla long, extending to point well ventral to horizontal drawn from ventral border of eye in all specimens. Maxilla extends posteriorly to anterior to vertical drawn through anterior border of pupil of eye in males, between anterior border of eye and pupil in females and juveniles.

Dorsal-fin unbranched rays ii in all specimens, branched rays 8-9 (8) [8.0], 8, n = 63; posterior ray not split to its base and counted as 1 ray. Adipose fin not elongate or slender ( Figs.11 and 12 ). Unbranched anal-fin rays iv or v, typically iv, branched rays 20-25 (22) [22], 22.0, n = 59. Posterior anal-fin ray split to its base but counted as 1 ray ( Fig. 16 ). Anal fin with moderately developed lobe anteriorly ( Figs. 11 , 12 , 16 ); lobe formed by anterior undivided rays and first 4 or 5 divided rays. Anal fin of sexually mature males with bilateral hooks, usually anterior fifth unbranched ray with approximately 10 hooks, 1 hook per segment. First branched ray with approximately 7 hooks, 1 hook per segment. Number of hooks decreasing until sixth or seventh branched ray which bear 1 hook only on each side, all remaining branched fin rays with 1 hook rarely 2 on each side, except last divided ray which bears no hooks. Pectoral-fin unbranched ray i in all specimens, branched rays 9-13 (11) [11], 10.7, n = 63. Tip of pectoral-fin extends beyond origin of pelvic fins; pectoral fins of about equal extent in both sexes. Pelvic-fin rays i, 6 [7, anterior ray

Males Females and juveniles

Characters

N Range Mean SD Holotype N Range Mean SD dif. Standard length 23 26.5-44.6 36.0 37.4 40 24.5-55.0 33.9

Depth at dorsal-fin origin 23 27.0-34.5 31.7 1.9 34.2 40 27.0-34.6 30.5 1.8 – Snout to dorsal-fin origin 23 53.3-58.5 55.5 1.4 57.0 40 56.0-59.0 55.8 1.4 – Snout to pectoral-fin origin 23 23.6-28.0 25.6 1.1 26.2 40 23.2-27.6 25.3 1.0 – Snout to pelvic-fin origin 23 42.7-51.8 44.3 2.2 43.8 40 42.1-47.1 44.7 1.1 – Snout to anal-fin origin 23 55.5-61.0 58.2 1.5 59.1 40 57.3-62.3 59.2 1.3 – Caudal peduncle depth 23 12.0-18.2 14.7 1.6 15.0 40 10.6-16.8 13.4 1.3 – Caudal peduncle length 23 09.7-13.0 11.6 0.9 10.7 40 10.0-14.2 11.6 1.0 + Pectoral-fin length 23 20.8-25.3 22.8 1.1 23.0 39 19.8-24.9 22.0 1.1 – Pelvic-fin length 23 14.3-18.6 16.2 1.2 16.3 39 12.3-17.1 15.6 0.9 – Dorsal-fin base length 23 11.3-14.2 12.7 0.7 12.0 40 10.0-13.4 12.1 0.8 – Dorsal-fin height 23 22.5-26.5 24.3 1.2 24.0 39 20.1-26.8 24.0 1.3 – Anal-fin base length 23 29.0-36.1 33.8 1.8 35.3 40 28.5-35.3 32.8 1.4 – Anal-fin lobe length 23 18.1-24.1 21.2 1.3 18.7 40 18.1-23.2 20.4 1.3 – Eye to dorsal-fin origin 23 41.0-45.2 42.6 1.2 43.3 40 40.0-45.3 42.7 1.3 – Dorsal-fin origin to caudal-fin base 23 46.5-51.7 49.0 1.2 50.8 40 46.2-50.8 48.4 1.2 – Bony head length 23 24.4-28.4 25.8 1.0 26.4 40 23.7-27.8 26.0 1.1 – Horizontal eye diameter 23 35.5-41.2 38.0 1.8 37.3 40 36.1-41.1 38.3 1.2 – Snout length 23 18.5-24.3 21.1 1.7 18.2 40 17.1-23.0 19.8 1.6 – Least interorbital width 23 30.0-32.7 31.4 0.8 33.3 40 29.7-34.2 32.0 1.2 – Upper jaw length 23 40.0-47.1 45.0 1.6 45.5 40 41.6-48.8 45.3 1.5 –

branched]. Branching of, first ray variable in population samples at hand; i, 6 in 27 specimens with i, 8 in one specimen; anterior ray branched in 21 specimens. Sexually mature, large adult males with over 300 hooks, many of them minute on rays of each pelvic fin. Principal caudal-fin ray count 10/ 9 in all specimens (n = 44), but reduced in some malformed specimens. Principal caudal-fin rays 11 and 12 modified by being bowed ventrally in association with putative pheromone glandular tissue ( Fig. 15 ). Glandular tissue granular or beaded in appearance, confined to principal caudal-fin rays 10-15 in fully mature males ( Figs. 13 and 14 ).

Scales cycloid, with 5-7 radii along posterior border. Terminal scale of modified caudal-fin series of mature males without complex and increased number of radii ( Fig. 15 ).

Lateral line incomplete ( Fig. 11 ), pored scales 7-27 (7) [12], 13.8, n = 43. Lateral series scales 37-42 (39) [40], 39.9, n = 40. Predorsal scales 15-18 (15) [16], 16.8, n = 44. Scale rows between dorsal-fin and anal-fin origins 13-16 (14) [15], 15.1, n = 44. Scale rows around caudal peduncle 17-19 (18) [18], n = 38.

Premaxillary teeth in 2 distinct rows ( Fig.18 ). All teeth tricuspid or occasionally quadricuspid in large specimens; smaller specimens with smaller sometimes bicuspid or conical. Outer row teeth 2-5 (3) [5], n = 36. Smaller specimens tend to have lower counts. Inner row teeth few 4-5 (4) [4], 4.3, n = 45. Maxillary teeth 3-9 (6) [4], 4.8, range 3-9, larger specimens usually with higher counts, n = 45. All maxillary teeth ( Fig. 18 ) usually tricuspid in large specimens; small specimens with posterior maxillary teeth conical Dentary with 4, (4 large quadricuspid to pentacuspid teeth in all adult specimens), followed by smaller posterior teeth 5-10 (7) [8], 8.1, number of teeth typically greater in largest specimens. Anterior small teeth of posterior portion of dentary tooth row usually tricuspid but sometimes bicuspid, with posterior teeth conic, n = 42 ( Fig. 18 ). Maxillary and dentary teeth shaped much like premaxillary teeth. No significant difference in tooth numbers found between males and females.

Vertebrae 36-38 (36) [37], n = 45. Dorsal limb gill-rakers 5- 8 (5) [7], n = 44; ventral limb gill rakers 9-13 (10) [11], n = 44. Branchiostegal rays 4 in 2 cleared and stained specimens; 3 rays originating on anterior ceratohyal and 1 ray from posterior ceratohyal.

Color in alcohol. See Figs. 11 and 12 for preserved color patterns of males and females. Color description of preserved adults from specimens collected within last 20 years. Color pattern of types of H. melanopleurus faded but dark narrow stripe along body sides illustrated by Ellis (1911: plate III) still visible. Color patterns of the types of G. melanogenys is too faded for useful description, but appears comparable to those of G. melanopleura . Body pale to medium brown, pale yellowish brown ventrally, somewhat darker dorsally. No obvious discrete lateral body stripe present in adults but a diffuse brown pigment on body sides of males darker along body midsides as shown in Fig. 11 . Female ( Fig. 12 ), with same but paler pigment. Vertically elongate humeral spot present, paler in female than in male. Dark spot present at dorsal termination of gill opening and separated from humeral spot by clear area. Dorsal body surface dark brown, forming a stripe extending from supraoccipital region to base of dorsal procurrent rays of the caudal fin. Remainder of body surface ventral to diffuse lateral body stripe pale brown.

Pectoral and pelvic fins hyaline with a few scattered dark chromatophores. Dorsal, anal, and caudal fins dusky with scattered dark chromatophores along their fin rays and membranes.Anal fin with dark, diffuse, elongate stripe running length of base of fin. This is darker posterior to anterior anal-fin lobe. Stripe’s width about one fourth height of anal fin anteriorly and about one half fin’s height posteriorly. Distal part of anal fin hyaline but appears dark in Fig. 11 due to background color in photograph. Anterior anal-fin lobe hyaline. Dorsal-fin, adipose fin, and caudal fin dusky with scattered dark chromatophores. Dorsal border of first principal pigmentation occurs in adults of both sexes.

Head dark brown around mouth and on dorsal surface of snout, between eyes, dorsum of cranium and nape. Mental area of lower jaw brown. Head area posterior to infraorbitals and extending ventrally from parietal region across dorsal opercular region dark brown to brown in both sexes. Dark area continues ventrally across posterior region of orbital bones and occurs on posterior region of opercle reaching interopercular bone. In Fig. 11 , ventral half of opercle of male is covered with very dark chromatophores. Exposed area of cleithrum dark brown. Iris dorsal to pupil dark brown, most of remainder of iris silvery. Infraorbitals silvery if guanine is preserved, pale yellowish brown if guanine is absent.

caudal-fin ray and ventral border of nineteenth principal caudal-fin ray black. Posterior borders of dorsal and ventral lobes black in both sexes (compare Figs. 11 and 12 ). Fin-ray membranes in the area of caudal glandular tissue, especially that between rays 7-14 black with dark chromatophores. Dark chromatophores also present between rays 14-19. This Color in life. Life colors described here taken from color slides made of live adult sexually-active males and females from just east of Campo Grande, São Paulo State, 7 October 1977. Specimens photographed alive in a small aquarium immediately after capture from clear water stream discussed in section on ecology.

Sides of body are pale silvery tan with lateral body stripe hardly noticeable, but area of stripe is somewhat deeper brown and in part underlain by guanine. Body weakly translucent. Humeral spot or blotch not evident. Body scales not posteriorly bordered in black, being translucent. Body lacks blue pigment. Lateral body stripe weakly present at junction of epaxial and hypaxial muscles. Pigment of lateral body stripe about one to two scales wide and appears deep, internal to skin. This mostly due to presence of dark chromatophores close to muscle tissue. Stripe mostly ends posteriorly at about posterior termination of penultimate vertebra. Caudal peduncle posterior to this area sometimes almost without pigment. Back dorsal to lateral body stripe light brown. Dorsal region of caudal peduncle colored the same as back. Ventral abdominal area, most of lower jaw, ventral opercular area, branchiostegal rays, and their membranes silvery white. Lateral region of opercle translucent and therefore appears red due to blood in gills. Dark pigment of head similar to that described for preserved specimens except that dorsal region of opercle and anterior end of body stripe silvery green. Most areas of head similar to back in color. Brain easily seen through translucent head and appears golden. Lower jaw with pale brown to sometimes dark brown band extending through mental region. Caudal-fin lobes bordered in black and non-black areas of fin rays (but not the membranes) colored pale brick red. This red pigment usually darker in males. Region equivalent to pheromone organ in other species of the Glandulocaudinae not colored black or at least not as black as in species of Mimagoniates . However, a small amount of black pigment is present on principal caudal-fin rays 10 and 11. Anal fin with distal portion of anterior anal-fin lobe yellow to orange, of deeper color in males than in females. Yellow to orange color covers approximately distal halves of posterior undivided ray and anterior 4 or 5 branched rays. Distal ends of branched rays posterior to anal-fin lobe tipped with black and some specimens with broad, more or less mottled black band at the distal border of the anal fin posterior to the anterior lobe. Basal region of anterior 5 or 6 divided anal-fin rays colored by narrow black band often suffused with orange or brick red. Remainder of fin hyaline. Pelvic fins yellow to orange, including skin covering distal portion of pelvic girdle. Pectoral fins yellow to orange, darkest in males. Pectoral and pelvic fins otherwise hyaline. Dorsal fin hyaline, yellowish in females and males but males with dusty black longitudinal stripe through their mid length. Distal ends of dorsal-fin rays dusty black.

Types of Hyphessobrycon melanopleurus not faded as types of Glandulocauda melanogenys . Immature specimens of H. melanopleurus still display a color pattern similar to that illustrated in the somewhat retouched photograph in Ellis (1911: plate III, fig. 2) in which a dark, narrow lateral band extends from dorsal corner of gill slit posteriorly onto caudal fin. Types of H. melanopleurus differ in having dark chromatophores of anterior half of dark lateral stripe darker and more concentrated into a narrow rather well defined stripe, whereas in recently collected specimens the chromatophores in this area more diffuse and lighter. We examined closely at some paratypes of G. melanogenys (FMNH 15025) which have retained their color better than its other types and were able to detect some of same differing color pattern as found in types of H. melanopleurus . No other differences were found in other examined features.

We conclude that these specimens are conspecific and that color pattern differences may be correlated with seasonal variation in color pattern at the time and preservation.

Sexual dimorphism. Females lack glandular caudal tissue found in males (compare Figs. 11 and 12 ). Although females and juveniles have the modified caudal squamation of the males ( Fig. 12 ), their modified scales are smaller and less obvious. Furthermore, females completely lack the anal- and pelvic-fin hooks found in males.

Live color pattern differences of males and females from type locality in breeding condition and collected from type locality are similar overall. Breeding males have intensely orange-golden pectoral fins while those of females are pale orange to pale yellow. Males usually with more red on the caudal-fin rays than females and in some specimens this pigment is concentrated and relatively intense in central areas of each caudal-fin lobe. Males usually with more intense yellow or pale orange color in distal portion of anterior anal-fin lobe, pelvic fins and dorsal fin. Otherwise sexually mature specimens of both sexes have same coloration.

Among the statistically significant sexually dimorphic morphometric characters indicated in Table 3, only caudal peduncle depth proved to be different through regression analysis. Linear regressions prepared for males and for females plus juveniles passed all tests for the linear regression model. Figure 19 indicates that males reach greater lengths than the females and that there is a divergence in caudal peduncle depth between males and females beginning at about 38 mm SL.

Distribution. Glandulocauda melanopleura is known from the upper rio Tietê area of the upper Paraná basin and adjoining upper portions of the coastal rivers Guaratuba, Itatinga and Ribeira de Iguape flowing into the Atlantic Ocean in the State of São Paulo, Brazil. See fig. 3 in Menezes et al. (2008) as Glandulocauda melanogenys .

Remarks. Three large females (MZUSP 26891), 21 specimens (MZUSP 48511) collected from córrego Mutuca, and 1 specimen out of 7 collected in Campo Grande, São Paulo State, of G. melanopleura have the branched anal-fin rays in the range of those for G. caerulea , 17, 18 and 19. These specimens however, are very similar to the specimens of G. melanopleura with respect to all the other meristic and morphometric characters. We did not include them in our data sets until more specimens from these locations are available for a more detailed analysis.

Three specimens of G. melanopleura recently collected from a tributary of the rio Ribeira drainage ( MZUSP 79429 ) represent the first record of the species outside the upper Tietê drainage .

Ten specimens from a small tributary of rio Guaratuba which empties into the Atlantic Ocean (MZUSP 84412) have branched rays counts (18-20, mean = 18.6) with lower values and counts of longitudinal scale rows from dorsal-fin origin to anal-fin origin (16-17, mean = 16.6) and scales around caudal peduncle (18-20, mean = 19.3) with higher values than those for specimens from the type-locality or near it, respectively 20-25 (mean = 22.00), 13-16 (mean = 15.1) and 17-19 (mean = 18.0). Since the ranges overlap and all the other meristic and morphometric characters of these specimens are very similar to those of the specimens of G. melanopleura from the type locality or near it we prefer to consider both samples conspecific until more specimens from rio Guaratuba are available for study. Two specimens from the rio Itatinga, Parque das Neblinas, São Paulo, were identified as G. melanogenys (Serra, Carvalho & Langeani, 2007) , but we not examined this sample. Other populations of G. melanopleura with variations in number of anal-fin rays and a few other meristic counts are likely to be discovered (see discussion in Menezes et al., 2008). We tentatively consider all these populations G. melanopleura until more specimens permits more detailed analyses.

Notes on ecology and conservation. This species has been recently collected from its type locality, Alto da Serra and nearby ecological reserves or stations. It apparently is confined to the upper reaches of the upper rio Tietê adjacent river basins, especially in forested areas and was recently considered vulnerable in the State of São Paulo (Menezes & Lima, 2008). The portion of this stream, where the fish is known to occur, between and near Paranapiacaba, SP, and Campo Grande, SP, is much limited in downstream length by the dammed up waters of the artificial lake, the represa do Rio Grande. Glandulocauda melanopleura apparently requires a stream environment with cool flowing water for successful reproduction and is not known from the lake.

The area where Glandulocauda melanopleura survives, about 750 meters in elevation, was originally mostly a tropical pluvial submountain forest. Except for areas within the Estação Biológica de Boracéia and Reserva Biológica de Paranapiacaba, it is now partly cleared for farming and for railroad yards. Although the area near the stream occupied by G. melanopleura is still forested it is being cleared to accommodate summer homes. Pollution from these homes or the railroad could result in the extinction of the fish in the area.

The populations of G. melanopleura may already be suffering from the effects of pollution. The local air pollution from Cubatão, SP, water pollution from a chlorine plant a few kilometers downstream from Campo Grande, SP, and/or occasional pollution from railroad freight cars since late in the last century may account for the relatively high number (total 8 out of 84 specimens) of deformed individuals in our collections.

Notes on type locality. The locality Alto da Serra was collected by John D. Haseman while travelling through eastern Brazil by train in 1908 but does not appear on modern maps. An old railroad map of Brazil in the Harvard University, “Mappa Ferroviario, Edição 1917”, shows Alto da Serra where today Paranapiacaba is located. The American Geographical Society Map of Hispanic America , section “S. F-23, Rio de Janeiro ”, provisional edition for 1938 shows Alto da Serra at 23°45’S 46°20’W, approximately the location of Paranapiacaba today. In 1975 we found a metal sign, bearing the words Alto da Serra , which was partly broken away but still attached to an old railroad station at what is now Campo Grande , SP. We are unable to explain the presence of this sign at what today is Campo Grande , SP, 8 km west of Paranapiacaba , SP, since both Campo Grande and Alto da Serra appear on old railroad maps of Brazil. Perhaps Haseman collected at Campo Grande and reading the sign “Alto da Serra” entered that as his locality. According to Eigenmann (1911a: 305) Haseman’s notes stated that this locality was characterized by “Small rills with an abundance of algae and reeds”. This description could apply to either locality but it best fits Campo Grande where there are several small streams. The stream at Paranapiacaba consists of one small stream with a few small tributaries. We , thus, lean towards Campo Grande , SP, as the type locality; however, the possible confusion is because the main headwater stream involved begins just north of Paranapiacaba then flows through Campo Grande, SP. The species in question is present at both localities and areas in between, albeit today more abundant at Campo Grande , SP, where the stream is not as steep on more level ground and is deeper and slower. See ecological notes .

Material examined. Holotype of Hyphessobrycon melanopleurus . FMNH 54413, immature, 23.4 mm SL, Brazil, São Paulo, município of Santo André,Alto da Serra, headwaters of rio Tietê, approximately 23º45’S 46º20’W, 25 July 1908, J. D. Haseman. Paratypes of H. melanopleurus . Collected with holotype: FMNH 54414, 2 immatures, 25.5-26.8 mm SL. Holotype of Glandulocauda melanogenys . FMNH 54891, adult male, 37.4 mm SL, same type locality and date of collection as for H. melanopleurus above. Paratypes of G. melanogenys . Collected with holotype: FMNH 15025, 1 immature male, 31.3 mm SL; FMNH 15026, 1 adult male, 35.0 mm SL; FMNH 54892, 5 males, 4 females, immature to adults, 25.3-40.2 mm SL, 5 juveniles, 23.3-25.4 SL; USNM 177724, 2 immature and adult males, 32.1-40.0 mm SL; CAS(IUM) 13287, 2 immature and adult females, 33.5-36.2 mm SL. Non-Types. All collected in Brazil. São Paulo State, município de Santo André: MZUSP 1869, 4 males, 3 females, adults, 36.3-44.6 mm SL, Campo Grande; MZUSP 26891, 3 adult females, 45.6-55.0 mm SL, Reserva Biológica de Paranapiacaba, Universidade de São Paulo; MZUSP 26890, 1 immature, 30.6, 3 adult females, 39.0-41.0 mm SL, 2-3 km north of Campo Grande, headwaters of rio Tietê; USNM 236414, 1, adult female, 41.2 mm SL, approx. 1/2 distance between Campo Grande and Paranapiacaba, headwaters of rio Tietê, approx. 23°46’S 46°19’W; USNM 236415, 2 males & 4 females, adults, 32.8-42.3 mm SL, Campo Grande, head waters of rio Tietê; USNM 236093, 2 cleared and stained, 1 adult female and 1 male, adults, 39.3-40.2 mm SL, same data as preceding collection; MZUSP 26892, 2 males and 1 female, adults, 32.8-38.3 mm SL, (1 male abnormal with ventral caudal region reduced in size, not counted or measured), same data as USNM 236415; MZUSP 35242, 7 adult females and males, 36.0- 40.2 mm SL, 1 immature female, 34.3 mm SL, stream near Paranapiacaba; MZUSP 28849, 10 immatures, 26.9-32.7 mm SL, stream tributary to rio Grande, Campo Grande. Following two lots collected in Brazil, São Paulo State, município of Salesópolis, Estação Biológica de Boracéia; MZUSP 48511, 5 juveniles, 19.5- 24.3 mm SL, 6 immature to adult females, 29.0- 39.2 mm SL, córrego Mutuca, 23º40’S 45º53’W; adult MZUSP 84412, 7 immature to males, 25.0- 39.4 mm SL, 3 immature females, 20.5-29.8 mm SL, córrego tributary of rio Guaratuba, Trilha do Mirante, Estação Biológica de Boracéia, 23º40’8.5”S 45º53’55.1”W; MZUSP 79429, 2 males and 1 female, adults, 37.5-51.0 mm SL, stream tributary of rio Juquiá flowing into rio Ribeira drainage, fazenda Santa Rita, município de Juquitiba, 23º57’51.5”S 46º56’20.7”W.

Figures

Fig. 11. Glandulocauda melanopleura, adult male. USNM 236415, 42.3 mm SL, Brazil, São Paulo State, headwater stream of rio Tietê near Paranapiacaba. Modified from Weitzman et al. (1988).

Fig. 12. Glandulocauda melanopleura, adult female. USNM 236415, 37.5 mm SL, São Paulo State, headwater stream of rio Tietê near Paranapiacaba. Modified from Weitzman et al. (1988).

Fig. 16. Glandulocauda melanopleura, adult male, USNM 236415, 42.6 mm SL; anal-fin rays, lateral view, left side.

Fig. 15. Glandulocauda melanopleura, adult male, USNM 236093, 40.2 mm SL; osteology of caudal skeleton and caudal-fin squamation of dorsal portion of caudal-fin lobe (lower left insert), lateral view, left side, anterior at left.Modified from Menezes &Weitzman (1990).

Fig. 13. Glandulocauda melanopleura, adult male, USNM 236415, SL 42.3 mm; caudal fin and caudal peduncle of adult male. Modified from Weitzman et al. (1988).

Fig. 14. Glandulocauda melanopleura, adult male, USNM 236415, 42.3 mm SL: detail of caudal organ showing beaded glandular tissue indicated by arrow. Lateral view, left side. Modified from Weitzman et al. (1988).

Fig. 18. Glandulocauda melanopleura, adult male, USNM 236415, 42.6 mm SL; jaws and dentition, lateral view, right side, anterior at right.

Fig. 19. Glandulocauda melanopleura, caudal peduncle depth as function of SL by sex. Plots illustrate difference between sexes in this feature.See text under sexual dimorphism for further explanation.