Aphanotorulus ammophilus ( Armbruster and Page 1996 )

Ray, C. Keith & Armbruster, Jonathan W., 2016, The genera Isorineloricaria and Aphanotorulus (Siluriformes: Loricariidae) with description of a new species, Zootaxa 4072 (5), pp. 501-539 : 508-512

Aphanotorulus ammophilus ( Armbruster and Page 1996)

( Fig. 4 )

Aphanotorulus ammophilus Armbruster & Page, 1996: 385 , fig. 2 (middle). Type locality: Venezuela, Estado Cojedes, Río San Carlos, R. Portuguesa drainage at Caño Hondo, 2 km west of Las Vegas on the road from Las Vegas to Campo Allegre – 9º31'51"N, 68º39'39"W. Holotype: INHS 32035, 86.0 mm SL.

Material examined. See Armbruster and Page (1996) and Armbruster (1998).

Diagnosis. Aphanotorulus ammophilus differs from all congeners, except A. unicolor , by its numerous buccal papillae ( Fig. 5 ). Aphanotorulus ammophilus differs from A. unicolor by the presence of ridges on the compound pterotics on the head (vs. ridges absent in A. unicolor ); in having a pectoral fin that, when depressed, reaches well past insertion of last pelvic-fin ray (vs. pectoral fin extending at most to insertion of last pelvic-fin ray in A. unicolor ). See diagnosis of A. unicolor below for further diagnostic features for specimens greater than 75mm SL.

Description. Morphometric data given in Table 2 . Head slightly compressed with raised supraoccipital crest; crest ending abruptly with posterior edge perpendicular to head. Sharp ridge present on compound pterotics. Large flap covering posterior opening of nare. Interorbital surface flat. Nape increasing in height posteriorly to dorsal fin.

Dorsal-fin spine slightly longer than or equal in length to first dorsal-fin ray. Pectoral-fin spine reaches past point of insertion on pelvic fin. Pelvic fin spine reaches insertion of anal fin. Adipose-fin membrane extending to end of fourth adipose base plate (two plates separate adipose-fin membrane and first dorsal procurrent caudal-fin spine).

Lateral line plates 28–30 (mode 29; n= 93); dorsal-fin base plates six to 10 (mode seven; n= 93); folded dorsal plates 10–14 (mode 13; n= 90); plates between dorsal and adipose fins seven to 10 (mode eight; n= 93); adipose-fin plates three to four (mode three; n= 92); anal-fin base plates two to three (mode two; n= 93); plates from anal-fin insertion to last plate on caudal peduncle 13–16 (mode= 14; n= 93); plates in folded pectoral fin five to seven (mode six; n= 93); number of teeth on dentary 9–20 (mode= 14; n= 92); number of teeth on premaxilla 10–18 (mode= 14; n= 92).

Sexual Dimorphism. Breeding males with elongated odontodes on dorsal and lateral surfaces of body posterior to insertion of dorsal fin, increasing in length and density posteriorly. Odontodes also present on pectoralfin spines and caudal-fin spines.

Color in alcohol. Light tan to almost white background. Ventral surface almost white. Dorsal and lateral surfaces with dark, round spots. Spots small to medium in size. Spots form longitudinal rows in some specimens, more random in others. Spots on caudal fin align to create vertical bars when fin is compressed. On dorsal fin, two rows of spots lie between each fin ray. Juveniles with four brown saddles, a brown midlateral stripe, and a mottled head.

Distribution. Río Orinoco drainage in Venezuela, mainly from the Río Apure system ( Fig. 6 ).

Figures

FIGURE 4. Dorsal, lateral, and ventral views of Aphanotorulus ammophilus, AUM 22659. Scale = 1 cm.

FIGURE 6. Distribution of Aphanotorulus ammophilus and A. unicolor. Circles represent A. ammophilus, squares represent A. unicolor. Open shapes represent type localities. From Armbruster (1998).

FIGURE 5. A. Ventral view of mouth of Aphanotorulus gomesi, ANSP 69409, illustrating the large central buccal papilla characteristic of most members of Aphanotorulus and Isorineloricaria. Photograph by M. Sabaj-Pérez and K. Luckenbill. B. Ventral view of mouth of A. ammophilus, AUM 22659, illustrating multiple buccal papillae found in A. ammophilus and A. unicolor.

Tables

TABLE 2. Selected morphometrics of Aphanotorulus ammophilus and A. unicolor.

	Aphanotorulus ammophilus	Aphanotorulus unicolor
Measurement	N Average SD Range	N Average SD	Range
Standard Length (SL, mm)	91 36.0–160.9	323	31.1–139.0
% SL
Predorsal Length	91 91.0 1.6 36.1–44.0	319 38.3 1.1	35.6–43.8
Head Length (HL)	91 33.3 1.9 29.2–38.5	323 31.5 1.5	19.0–38.2
Cleithral Width	91 26.7 1.0 24.4–29.6	317 26.0 1.2	23.2–31.6
Dorsal spine Length	72 26.4 1.8 21.6–29.5	270 28.4 1.9	22.4–34.1
Folded dorsal-fin Length	90 33.8 1.1 30.9–36.9	315 33.7 1.4	20.1–37.6
Dorsal-fin base Length	91 19.6 1.2 17.2–22.8	323 19.3 1.2	15.6–23.9
Dorsal- adipose Length	91 20.9 1.6 16.8–24.1	322 23.2 1.5	16.9–26.5
Thorax Length	91 24.5 1.2 21.3–26.8	319 25.5 1.3	21.1–32.4
Pectoral spine Length	91 29.8 1.5 26.0–33.8	322 28.6 1.4	25.0–32.1
Abdominal Length	91 21.7 1.0 19.2–24.4	319 23.1 1.0	20.0–25.5
Pelvic spine Length	91 19.3 1.0 17.1–22.5	318 20.8 1.0	16.4–24.2
Postanal Length	91 29.6 1.1 26.2–31.8	319 30.3 1.3	26.8–35.6
Caudal peduncle Depth	91 7.0 0.4 5.7–8.3	323 8.2 0.6	5.9–9.6
Caudal peduncle Width	90 12.9 1.0 9.7–16.1	317 14.7 1.4	10.6–17.9
Adipose-fin spine Length	90 8.5 0.9 5.7–10.6	315 8.3 0.8	6.6–10.8
%HL
Head Depth	91 46.5 4.0 36.7–55.4	317 51.9 8.1	35.0–100.6
Snout Length	91 51.1 2.9 43.4–56.8	321 51.0 6.6	40.2–147.9
Orbit Diameter	91 13.7 1.7 10.2–20.7	321 17.4 2.1	12.1–32.8
Interorbital Width	91 34.1 2.4 25.7–39.5	323 34.6 6.7	28.0–139.7
Snout opercle Distance	91 69.4 2.3 62.5–77.9	321 68.6 3.7	57.9–87.3
Head Width	91 78.9 3.9 66.7–88.8	321 80.6 6.2	67.6–145.0