Cercamia spio, Fraser & Bogorodsky & Mal & Alpermann, 2021

Fraser, Thomas H., Bogorodsky, Sergey V., Mal, Ahmad O. & Alpermann, Tilman J., 2021, Review of the cardinalfishes of the genus Cercamia (Percomorpha: Apogonidae) of the Red Sea and Indian Ocean with descriptions of three new species, Zootaxa 5039 (3), pp. 363-394 : 383-389

Cercamia spio new species

( Figures 4B , 14–17 , Tables 2 & 3)

Red Sea Nymph Cardinalfish

Cercamia eremia (non Allen)— Allen 1987: 4 (6 specimens from near Jeddah listed as paratypes, WAM P25793-003); Gon & Randall 2003: 30 (Gulf of Aqaba, description); Golani & Bogorodsky 2010: 27 (listed); Golani & Fricke 2018: 73 (listed).

Holotype. SMF 35891 [sample of tissue KAU13-451], 33.2 mm SL, Red Sea , Saudi Arabia, Al Wajh Bank, Station RSS1-2013-09(3), 25º37’1.80”N 36º53’17.20”E, 10–15 m, coll. T. J. Alpermann & S. V. Bogorodsky, 16 Jun 2013, photograph & radiograph.

Paratypes. SMF 35135 [KAU13-496], 1, 30.5 mm SL, data as for holotype ; SMF 35178, 5 , 17.8–30.2 mm SL, Red Sea, Saudi Arabia, Duba, Station RSS1-2013-29, 26°57’47.00”N 35°57’59.29”E, 10–15 m, coll . T.J. Alpermann & S . V. Bogorodsky, 20 Jun 2013, radiograph ; SMF 35892, 1 , 29.5 mm SL, Red Sea, Saudi Arabia, Duba, Station RSS1-2013-25, 27°05’42.32”N 35°46’42.39”E, 10–15 m, coll . T.J. Alpermann & S . V. Bogorodsky, 19 Jun 2013 ; SMF 35893 [KAU17-262 & KAU17-263], 2 of 26, 26.2–26.7 mm SL, Red Sea , Saudi Arabia, Jeddah , Obhur, Station RSS1-1, 12– 16 m, S . V. Bogorodsky, 16 Feb 2017, photograph ; SMF 35895, 4 , 28.0– 30.6 mm SL, Red Sea, Saudi Arabia, Jeddah , Obhur, Station RSS2-2017-110, 14– 16 m, S . V. Bogorodsky, 21 May 2017 .

Other material [paratypes of C. eremia ]. WAM P25793-003 , 6 , 25.0–31.0 mm SL, Saudi Arabia, near Jeddah , 21°28’N 039°08’E, 13 Apr 1977 .

Diagnosis. A species of Cercamia with anal-fin spines and rays usually II,11 (rarely 10 or 12); second dorsal-fin spine and rays I,9; developed gill rakers on upper limb 1, developed gill rakers on lower limb usually 11 (rarely 10); translucent, body with reddish dots and crosshatching, and curved iridescent bluish band over abdominal cavity; cheek with stellate melanophores ( Figs 14 & 15 ).

Description. Holotype: For general body shape see Figure 14 A-D, proportions (as percentages of standard length), paratypes in parenthesis: greatest body depth 26.6 (24.8–27.5); head length 38.9 (33.9–38.6); eye diameter 9.3 (8.0–8.8); snout length 9.6 (7.7–8.1); bony interorbital width 4.5 (5.4); upper-jaw length 18.4 (17.9–19.7); caudal-peduncle depth 11.7 (10.6–11.3); caudal-peduncle length 26.5 (25.2–28.2); first dorsal-fin spine 8.0 (7.6– 8.5); second dorsal-fin spine length 10.2 (10.2–12.3); third dorsal-fin spine length 8.8 (10.2–11.0); fourth dorsal-fin spine length 5.8 (7.7–8.2); spine in second dorsal 8.1 (7.5–10.4); first anal-fin spine length 1.5 (1–2.6); second analfin spine length 7.9 (7.5–10.5); pectoral-fin length 21.4 (22.4–25.1); pelvic-fin length 13.2 (11.9–12.9).

Dorsal fin VI–I,9, all segmented rays branched; anal fin II,12, all segmented rays branched, last anal-fin ray split to base; left pectoral fin with 10 rays, right removed; pelvic fin I,5; principal caudal-fin rays 9+8, upper and lower principal caudal-fin rays unbranched; procurrent rays 7 above, 7 below; caudal fin forked.

Scales mostly missing on body, a few cycloid scales on nape, near base of dorsal and anal fins and base of caudal fin; small reddish dots, one per scale or scale pocket at or near the confluence of scale edges on the body; dot counts suggest 24 linear scales on the body and appear consistent with myomeres; no pored or pitted scales observed on the body; free neuromast locations and patterns unknown on head, body or caudal fin.

First gill arch with 1 rudiment and 1 developed gill raker on upper limb, lower limb with no rudiment and 11 developed gill rakers. Premaxilla with 2–3 rows of tiny villiform teeth, exposed from anterior tip to near posterior end when mouth closed; dentary with 2 rows of tiny villiform teeth on side, a patch of slightly curved teeth at anterior tip; teeth absent on palatine, vomer, ectopterygoid, endopteygoid and basihyal.

Vertebrae 9+15; vertebral neural foramina present near base of neural spines, no inferior foramina near base of haemal spines; two hypurals 1+2+3+4 fused to terminal centrum as a deeply divided plate, hypural 5 free ( Fig. 16 ); short urostyle lacking a sheath; paired uroneurals absent; two epurals, parhypural closely appressed to hypural plate; second preural centrum with low crest; 9 ribs, first rib articulates with third vertebra, second rib articulates with fourth vertebra, thereafter ribs articulated with parapophyses, the last present on ninth vertebra’s parapophysis and about half the length of the eighth rib; supraneurals absent; one supernumerary spine on first dorsal pterygiophore; neural spines and dorsal elements 0/0/01/2/1/; anal pterygiophores 2/3 with the first haemal arch; basisphenoid not determined; supramaxilla absent; posttemporal with a single tiny spine on the margin; preopercular ridge with a single tiny spine at angle; edge with two separated tiny spines; infraorbital edges smooth.

Paratypes: Dorsal fin VI –I,9, all segmented rays branched; anal fin II,10–12 (usually 11), all segmented rays branched, last anal-fin ray split to base; pectoral fin with 10 rays, one paratype with 9 rays; pelvic fin I,5; principal caudal-fin rays 9+8, upper and lower principal caudal-fin rays unbranched; procurrent rays 7 above, 7 below; caudal fin forked .

Scales mostly missing on body, a few cycloid scales on nape, near base of dorsal and anal fins and base of caudal fin; small reddish dots, one per scale or scale pocket at or near the confluence of scale edges on the body; dot counts suggestion 24 linear scales on the body and appear consistent with myomeres; no pored or pitted scales observed on the body; free neuromast locations and patterns unknown on head, body or caudal fin.

First gill arch with 1 rudiment and 1 developed gill raker on upper limb, lower limb with 0–1 rudiment and 10–11 (usually 11) developed gill rakers. Premaxilla with 2–3 rows of tiny villiform teeth, exposed from anterior tip to near posterior end when mouth closed; dentary with 2 rows of tiny villiform teeth on side, a patch of slightly curved teeth at anterior tip; teeth absent on palatine, vomer, ectopterygoid, endopteygoid and basihyal. Posttemporal with a single tiny spine on the margin; preopercular ridge with a single tiny spine at angle; edge with two or three separated tiny spines ( Fig. 4B ); infraorbital edges smooth.

Life color. See Figure 14A for holotype and Figure 15 for other fishes. Head, body and fins translucent except for eyes, top of head and abdominal area; iris with narrow bluish ring around pupil, iris otherwise dark yellow with some iridophores; head and body with numerous erythrophores forming reddish markings; head and jaws with small reddish or reddish orange spots, snout and lips mostly reddish or orangish red, infraorbital region with a single line of small reddish spots, opercle and branchiostegals with a few reddish spots, upper anterior portion of opercle mostly reddish, pinkish hue below eyes extending to preopercle and anterior upper opercle may be partial effect of the red gill membranes showing through; patch of melanophores on interorbital area and postorbital head; base of caudal fin with thin vertical line of closely spaced tiny reddish spots; internally the abdominal area blackish along and just below vertebrae and above whitish swimbladder, wide blackish peritoneum area below swimbladder, upper part of peritoneum with narrow rows of iridophores producing a curved iridescent reflective, metallic blue, narrow band; fin rays reddish, fin membranes translucent, second dorsal fin with one mid-line of more intense small red spots, a less intense more distal line, anal fin with one developed line of intense small reddish marks, pectoral and pelvic fins with small intense reddish spots or unmarked.

Postmortem Color. Based on holotype ( Fig. 14B ) and paratypes (not shown). Head and body with scattered reddish spots on a whitish background, spots on head small to moderate size, most intense on side of snout and chin, single row on lower infraorbital area, single row on maxilla ending with two spots; area behind eye with moderate stellate melanophores; each branchiostegal with single row of spots; narrow reddish lines from contracted intense erythrophores tend to form a lattice-like effect on body behind head, organized approximately one per scale; pectoral fin with two rows of tiny spots near base; single line of reddish spots in second dorsal-fin rays and anal-fin rays; anal opening near anal fin with surrounded by whitish tissue; peritoneum with dense melanophores; swimbladder appears whitish between blackish above and below.

Color in alcohol. See Figure 14C for holotype. Nine stellate melanophores behind eye and anterior to upper limb of preopercle, head with a few small melanophores above eye, body pale without color, fins translucent, iris black, abdominal area showing partially greyish to blackish from internal pattern.

Etymology. Spio, a mythical sea nymph, daughter of Nereus and Doris, the Nereid of sea caves, latinized from Greek speio, a feminine noun in apposition.

Distribution and Habitat. A Red Sea endemic, known from Saudi Arabia and Egypt ( Fig. 17 ). Has been observed at night, usually in the vicinity of a cave, at depths of about 10– 30 m. A single individual at Dahab was observed solitary, although a large group of specimens was collected from the cave in Obhur, Jeddah suggesting that the species living in small groups in crevices.

Remarks. One specimen out of the 14 paratypes had four tiny teeth on the vomer, two on each side. All other specimens lacked evidence of any vomerine teeth. Caudal skeleton matches well to those described for C. eremia by Hayashi (1991) and we agree that hypurals 1–4 are fused and also fused to the terminal centrum for C. spio ( Fig. 16 ).

Cercamia spio differs from C. eremia , C. laamu and C. mascarene ( Tables 2 & 3) in having fewer anal-fin rays (usually 11 versus 12–13) and fewer develop gill rakers on lower limb (usually 11 versus 12–13), and in the presence of oblique iridescence bluish band dorsoposteriorly on the peritoneum. Cercamia spio is morphologically similar to C. melanogaster sharing similar fin-ray and gill rakers counts and the presence of iridescence bluish band on peritoneum but differs by having stellate melanophores behind the eye versus none, and by the presence of reddish or reddish orange chromatophores from the tip of the jaws to the opercle and on the rest of the head versus pale from the tip of the jaws to the opercle and the rest of the head (including side of snout, chin, and postorbital head) uniformly reddish.

In the phylogenetic analysis, C. spio forms a monophyletic clade that is the sister to a clade of specimens identified as C. cladara . There is no marked intraspecific variation in the sampled COI barcoding region (mean intraspecific p-distance was 0.6).

Figures

FIGURE 4. Preopercular spines. A: Cercamia cladara, AMNH 75135, paratype, 23.3 mm SL; B: Cercamia spio, SMF 35178, paratype, 30.2 mm SL.

FIGURE 14. Cercamia spio n. sp., SMF 35891 [KAU13-451], holotype, 33.2 mm SL, Al Wajh, Saudi Arabia, Red Sea. A: live specimen; B: postmortem specimen; C: preserved specimen in 70% ethanol; D: positive from radiograph, arrow points to the ninth abdominal vertebrae. Photos by S.V. Bogorodsky (A & B), T. Fraser (C), S. Raredon (D).

FIGURE 15. Cercamia spio n. sp., live fishes. A: Al Wajh, Saudi Arabia, SMF 35135 [KAU13-496]; B. SMF 35893 [KAU17- 262], Obhur, Jeddah, Saudi Arabia; C: Dahab, Egypt, not collected. Photos by S.V. Bogorodsky.

FIGURE 16. Cercamia spio n. sp., SMF 35891 [KAU13-451], holotype, Al Wajh, Saudi Arabia, Red Sea, 33.2 mm SL. Positive from radiograph by S. Raredon. E=epural, H1 to 5=hypurals, HS= haemal spine, NC=neural crest, NF=neural foramina, NS=neural spine P=parhypural, PR=procurrent ray, TC=terminal centrum, UR=unbranched caudal ray.

FIGURE 17. Collection and photographic sites for Cercamia spio n. sp. (white circles, star = holotype, Red Sea only), Cercamia mascarene n. sp. (yellow star = holotype), Cercamia laamu n. sp. (blue star = holotype & blue circles = paratypes), Cercamia eremia (red circles, star = holotype).