Cercamia cladara Randall & Smith, 1988

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 : 369-373

Cercamia cladara Randall & Smith, 1988

( Figures 1–3 , 4A ; Table 2)

Frail Cardinalfish

Cercamia cladara Randall & Smith, 1988: 7 , fig. 2 (type locality, French Polynesia, Society Islands, Rapa; holotype: BPBM 31978)— Randall 2005: 197 (South Pacific); Williams et al. 2006: 255 ( Wallis Islands).

Holotype. BPBM 31978 , 27.1 mm SL, French Polynesia, Society Islands , Rapa, reef at entrance to Haurei Bay, JER 71-11-10, 15– 18 m, 10 Feb 1971.

Paratypes. All same data as holotype : AMNH 75135 , 23.3 mm SL, cleared and double stained ; CAS 61348, 28.5 mm SL ; NSMT-P44801 , 30.5 mm SL, digital x-ray from film ; USNM 290959 , 32.6 mm SL ; WAM P29655.001 , 25.7 mm SL .

Other material examined. Tonga: USNM 444209 , 19 , 21.6–33.5 mm SL, Ha’apai Group, Tuaniu Reef , 19°16’48”S 174°22’59”W , JTW 93-27 , 2– 7 m, 10 Nov 1993, photograph 1, 28.8 mm SL, glycerin with cartilage stain ; USNM 334714 , 26 , 16.8–38.8 mm SL, Tongatapu Group, Malinoa I., 21°01’39”S 175°07’21”E, 11–17 m, 27 Oct 1993, 1, 32 mm SL, glycerin with cartilage stain, dissected (reported as USNM 334713 , a typo). Society Islands : ROM 60988, 3 , 30.0– 32.5 mm SL, Moorea, half way down W side of Opunohu Bay off Green Beacon , 17°30’23.9998”S, 149°51’23.9998”E, RW89-26, 21.3 m, photograph, 11 Dec 1989 .

Diagnosis. A species of Cercamia with anal-fin spines and rays II,12–13; second dorsal-fin spine and rays I,9; developed gill rakers on upper limb 2–3, developed gill rakers on lower limb 14–16; translucent reddish body with reddish dots and crosshatching; cheek with stellate melanophores ( Fig. 1A ).

Distribution. Possibly distributed in the South Pacific only, from the Chesterfield Island (Coral Sea) and Tonga, east to French Polynesia. Additional study is needed to know its distribution.

Additional Description. Combined notes on a radiograph of paratype NSMT-P44801 ( Fig. 1B ), a cleared and stained paratype AMNH 75135 of 23.3 mm SL ( Fig. 2 ) and a cleared and stained specimen USNM 334714 of 32 mm SL ( Fig. 3 ). The latter specimen double stained, bone stain very faint, likely a combination of small size and too long in unbuffered formalin, cartilage stained elements dominate. Eye sclera a narrow circular cartilaginous ring; 0/0/1/2/1/ for anterior dorsal elements; one supernumerary dorsal-fin spine and one supernumerary anal-fin spine; distal radials on first four proximal middle pterygiophores of first dorsal fin, present on all second dorsal and anal fin pterygiophores; ribs start on third vertebra, epineurals on vertebrae 1 and 2, then on ribs of third and fourth vertebrae, on parapophysis of fifth to ninth vertebrae; basihyal absent; cleithrum narrow without upper posterior process; single postcleithrum thin, very long from near supracleithrum to edge of abdomen, well behind the pelvics ( Figs 2A , 3 ); first pharyngobranchial present, cartilaginous; interarcual cartilage long and slender; tooth patches on 2 nd, 3 rd, and 4 th epibranchial; no teeth on tongue; no developed supraoccipital crest; most bones poorly ossified; infraorbitals complete, shelves unknown.

Remarks. Randall & Smith (1988) did not include much osteological information for Cercamia cladara based on their cleared and stained specimen. Baldwin & Johnson (1999) cited literature and provided some new comparative information. Their published information was based on cleared and stained specimens identified in the list of material as C. cladara, USNM 341821 and USNM 444209 cataloged as C. eremia , both from Tonga. We think it needs study to determine if this is an undescribed species. They reported 2–5 short spines on the posterior edge of the preopercle ( Fig. 4A ), gill rakers on the second arch, two pair of epineurals, no basisphenoid and an unossified third epural. Although Bergman’s (2004) figure 1 shows the basic organization of the cephalic canals, she omitted the coronal commissure. Her illustration, figure 17 of C. cladara show evidence for a series of pores along this cross connection. Cercamia cladara differs from all known species of the genus by higher count of developed gill rakers 2–3 + 14–16 = 17–20 ( Randall & Smith 1988). The scales we examined are cycloid scales consistent with other species even though Randall & Smith described the scales as weakly ctenoid.

In the phylogenetic analysis of the COI barcoding region, Cercamia cladara specimens form a monophyletic clade (see Fig. 5 ). Two specimens representing the species were previously identified as C. eremia , the specimens were re-identified herein based on their placement in the phylogeny. These two specimens (FUT258-18 and FUT360- 18) were collected at Wallis and Futuna Islands and they differ in eight diagnostics (> 1.2 %), albeit translationally silent, nucleotide substitutions from the residual seven specimens of this species, which were collected from French Polynesia (Moorea or Gambier Islands). As detailed morphological examination of the sequence vouchers was not feasible in the frame of the current study, we are not aware of morphological distinctions among specimens of the two geographically separated populations. Overall intraspecific divergence with a mean p-distance of 1.1 %, however, appears to be relatively high in C. cladara over the sampled distribution range, when compared to other species of Cercamia studied herein (see Discussion). This clade is unlikely to survive with more molecular data based on geographic distance and known distribution of these two species. In the ML tree, the clade composing C. cladara forms a sister clade to the new species C. spio n. sp. from the Red Sea, from which it is well divergent.

Figures

FIGURE 1. Cercamia cladara. A: ROM 60988, 30.0 mm SL, Opunohu Bay, Moorea, French Polynesia, postmortem, by R. Winterbottom edited by T. Fraser; B: NSMT P44801, paratype, 30.5 mm SL, Haurei Bay entrance, Rapa, French Polynesia, positive digital scan of a radiograph by M. Hayashi edited by T. Fraser.

FIGURE 2. Cercamia cladara, AMNH 75135, paratype, 23.3 mm SL, cleared and double stained for cartilage (gray) and bone (black). A: Part of the pectoral girdle; B: Caudal elements. C=coracoid, E=epural, EC=epural cartilage, H1 to 5=hypurals, HS=haemal spine, HC=haemal cartilages, NC= neural cartilages, NCR=neural crest, NS=neural spine, P=parhypural, PC=postcleithrum, PU2 & 3=preural vertebrae, R=radial, S=scapula, TC=terminal centrum.

FIGURE 3. Cercamia cladara, USNM 334714, 32 mm SL, Tonga, cleared and double stained for bone and cartilage. B=basipterygium, CO=coracoid, CL=cleithrum, LI=ligament, PCL=postcleithrum, PLF=pelvic fin, SC=supracleithrum, R=radial, S=scapula.

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 5. Maximum likelihood phylogeny of partial mitochondrial cytochrome oxidase subunit 1 (COI) gene of members of the genus Cercamia (see Table 1) with Lachneratus phasmaticus as outgroup.Values on branches represent bootstrap proportions from 1000 replicates; scale bar shows average number of nucleotide substitutions. Sequence of holotype of Cercamia spio n. sp. in bold. Origin of sequences is as follows: (P) = present study; (I) = Isari et al. (2017); (B) = BOLD; (M) = Mabuchi et al. (2014); (TR) = Thacker & Roje (2009); (A) = Allen et al. (2015).