Aphredoderus sayanus Gilliams 1824

Aphredoderus sayanus Gilliams 1824

Yellowbelly Pirate Perch

Figure 4; Tables 3, 4

Scolopsis sayanus Gilliams, 1824: 81–82. Syntype: ANSP 12690, 49.1 mm SL, Fish pond at Harrowgate, near Philadelphia, Pennsylvania, U.S.A., 1824.

Aphredoderus sayanus Lesueur in Cuvier and Valenciennes, 1833.

Aphredoderus sayanus sayanus Boltz and Stauffer, 1993.

Syntype: ANSP 12690 (1), 49.1 mm SL, Fish pond at Harrowgate, near Philadelphia, Pennsylvania, U.S.A., 1824. Other material: (133 specimens, 19–88 mm SL).

Delaware: Kent County: UF 20792 (1), UF 24206 (1). Sussex County: JFBM 50004 (12), JFBM 50005 (6). New Jersey: Burlington County: JFBM 50207 (2), JFBM 50405 (7), NCSM 107824 (13), NCSM 107885 (12). Cumberland County: JFBM 50202 (7). Middlesex County: NCSM 63655 (2). Monmouth County: NCSM 62836 (12). New York: Suffolk County: JFBM 50407 (2) JFBM 50408 (2), JFBM 50472 (6). Virginia: Caroline County: JFBM 50385 (1), NCSM 60660 (3), NCSM 62041 (2),. NCSM 62042 (1). Essex County: JFBM 50400 (5). King and Queen County: JFBM 46097 (6), 50389 (2), JFBM 50387 (8). Louisa County: JFBM 50382 (2), JFBM 50383 (1). Richmond County: JFBM 50391 (9). Spotsylvania County: NCSM 59063 (5), NCSM 60701 (1), NCSM 61827 (1). Stafford County: NCSM 60594 (1).

Diagnosis: Aphredoderus sayanus differs from all Aphredoderus by the large head size (mean 33.8% SL vs. 31.2%–33.4 %), and strongly contrasting abdominal color vs. slightly contrasting abdominal color. This species is further differentiated from A. ornatus sp. nov by the absence of a lateral caudal peduncle stripe and higher caudal peduncle scale counts (mean 33 vs. 29). From remaining Aphredoderus this species differs by a higher dorsal spine count, four vs. three, occasionally higher anal spine count (almost always three vs. two or three), lower ray counts in pectoral fins (10 vs. 11), and a well-defined yellow pigment underneath the lateral line. From A. mesotrema this species differs by having caudal chevrons vs. a vertical caudal bar and a smaller eye. From A. gibbosus this species differs by having a larger eye (mean 25% HL vs. 23.9%).

Description: Dorsal, IV:11 (IV:10–11). Anal, III:7 (III:6/7). Pectoral 10 (10–11). Lateral scales 44 (42–46) scale rows above lateral line 8 (8–9), caudal peduncle scales 33 (31–36). Deep bodied, 33% maximum body depth in SL and rarely less than 30%. Large head 34% of SL. Postorbital length long, typically over 16% of SL. Deep caudal peduncle, about 15% of SL, particularly in Southern portion of range. Predorsal length average, about 46% of SL. Eye size average, around 25% of head length. Interorbital space average, eye approximately 86% of interorbital size.

Coloration: Dorsally black or brown, color sharply transitions to lighter yellow color on abdomen. Abdominal melanophores usually diffuse or absent leading to yellow or white abdomen. Two black triangular blotches over hypural on caudal peduncle, at times blends to form one large triangle or two connected triangles. Lateral line frequently outlined by light pigment.

Distribution: York River, VA north to coastal drainages in South Long Island, NY (Fig. 9). Occurs with A. ornatus in the Rappahannock and Potomac River drainages in Virginia.

Remarks: We examined a photograph and radiograph of syntype ANSP 12690. The specimen is bent, deformed anterior to the dorsal fin, and the abdomen of the fish has been removed. Gilliams noted a yellow underside of the specimen and made no mention of a black lateral stripe on the caudal peduncle. We refer mainly to Gilliams’ pigment description of the specimen, except for our count of 3 anal spines rather than 2 using a radiograph. Specimens from the type locality are presumed extirpated. We included 34 specimens from the Delaware River in New Jersey as the closest extant population.