Luzonichthys seaver, a new species of Anthiinae (Perciformes, Serranidae) from Pohnpei, Micronesia

Abstract Luzonichthys seaver, n. sp., is described from two specimens, 42-46 mm standard length (SL) collected from Pohnpei, Micronesia. Collections were made by divers on mixed-gas closed-circuit rebreathers using hand nets at depths of 90-100 m. Luzonichthys seaver is distinct from all other species of the genus in the characters of lateral line scales, gill rakers, pelvic fin length, caudal concavity and coloration. Of the six species of Luzonichthys, it appears to be morphologically most similar to L. earlei and L. whitleyi.


Introduction
The genus Luzonichthys Herre 1936 consists of six species of small, slender serranids within the subfamily Anthiinae, distributed throughout the tropical Indo-Pacific. The genus is distinguished from other anthiine genera in general body size and shape, and in possessing two fully separated dorsal fins, two opercular spines, and 11+15 vertebrae (Randall 1981, Randall andMcCosker 1992). The currently recognized species include L. earlei Randall 1981, L. microlepis (Smith 1955), L. taeniatus Randall and McCosker 1992, L. waitei (Fowler 1931), L. whitleyi (Smith 1955), and L. williamsi Randall andMcCosker 1992. Fowler 1931 originally established L. waitei within the genus Mirolabrichthys Herre 1927. Herre (1936 established the genus Luzonichthys with waitei as the type species, but classified it (as did Fowler 1931) within the family Pomadasyidae. Whitley and Colefax 1938 described the new genus and species Naurua waitei, and Smith 1955, unaware of Herre's genus Luzonichthys, described two additional species (microlepis and addisi) within Naurua, also placing M. waitei Fowler 1931 in this genus, thereby establishing N. waitei Whitley and Colefax 1938 as a secondary homonym of M. waitei Fowler 1931. Smith (1955 proposed the new name N. whitleyi as a replacement for Whitley and Colefax's species. Smith (1956) later reassigned the two species he described to Luzonichthys and suggested the two other species of Naurua may also belong to that genus. Fourmanoir (1977) proposed the species L. robustus from seven specimens taken from Mare, Loyalty Islands and one specimen from Kwajalein, Marshall Islands. Randall (1981) described the species L. earlei from specimens taken off Oahu, Hawaii and suggested that L. addisi and L robustus were junior synonyms of L. waitei, noting the type series of robustus included 4 different species of Luzonichthys, the holotype being L. waitei. Finally, in a revision of the genus Luzonichthys, Randall and McCosker (1992) described two additional new species of the genus, L. taeniatus and L. williamsi. With the description of the new species, L. seaver herein, the number of recognized species within Luzonichthys is raised to seven.

Materials and methods
Type specimens of the new species, Luzonichthys seaver, were collected at Pohnpei, Micronesia by hand net from depths of 90-100 m and deposited in the Bernice P. Bishop Museum, Honolulu (BPBM). Measurements and counts given here follow the methods outlined in (Randall and McCosker 1992). Proportional measurements are given as ratios of: standard length (SL; measured from the tip of the snout to the base of the caudal fin at the posterior edge of the hypural plate); head length (HL, measured from the median anterior point of the upper lip to the end of the longest opercular spine), or body depth (BD, measured as the maximum depth from the base of the spinous portion of the dorsal fin). Character values for the paratype are presented in parentheses, if different from those of the holotype. Meristics and measurements were compared with data obtained from the literature (Randall and McCosker 1992)  Tissue samples were obtained from the two individuals of L. seaver. Total genomic DNA was extracted from both samples using the 'HotSHOT' protocol (Meeker et al. 2007 and Fish-BCL (5'-TCAACYAATCAYAAAGATATYGGCAC-3'). Polymerase chain reaction (PCR) was performed in a 15 µl reaction containing 7.5 µl BioMix Red (Biolone Inc., Springfield, NJ, USA), 0.2 µM of each primer, 5-50 ng template DNA, and nanopure water (Thermo Scientific* Barnstead, Dubuque, IA, USA) to volume. PCR cycling parameters were as follows: initial 95°C denaturation for 10 min. followed by 35 cycles of 94°C for 30 sec, 55°C for 30 sec, and 72°C for 30 sec, followed by a final extension of 72°C for 10 min. PCR products were visualized using a 1.5% agarose gel with GelStarTM (Cambrex Bio Science Rockland, Inc., Rockland MA, USA) and then cleaned by incubating with 0.75 units of Exonuclease and 0.5 units of Shrimp Akaline Phosphate (ExoSAP; USB, Cleveland, OH, USA) per 7.5 µl of PCR product for 30 min. at 37°C followed by 85°C for 15 min. Sequencing was conducted in the forward and reverse direction using a genetic analyzer (ABI 3730XL, Applied Biosystems, Foster City, California) at the ASGPB Genomics Sequencing Facility at the University of Hawaii at Manoa. The sequences were aligned edited and trimmed to a common length using Geneious Pro v.6.1.6 DNA analysis software (Biomatters. http://www.geneious.com/). CO1 haplotypes were deposited in GenBank (accession numbers KP110513 and KP110514) and BOLD (dx.doi.org/10.5883/DS-LSE001).  Color of holotype in life: head excluding operculum predominately yellow (many scales with yellow margins and pink centers), yellow extending posteriorly on upper half of body from a line starting at approximately the tip of the opercular flap and top of pectoral fins to the eighth dorsal ray, fading to bright pink posteriorly. Operculum to lower half of body salmon pink. Pectoral and pelvic fins pale. Dorsal fins yellow with bases of rear dorsal rays pink. Anal fin rays yellow with pale membranes. Upper and lower base of caudal fin pink, extending posteriorly to approximately halfway to the tips; center of base of caudal fin white, fading to pale; posterior half of caudal fin yellow. Lower base of caudal peduncle with yellow band (Fig. 1).

Luzonichthys seaver
Color of holotype in alcohol: Pale, all fins colorless except the caudal which has purple spots on the base of each of the upper and lower segments, the upper extending anteriorly, dorsally on the caudal peduncle.

Etymology
Named seaver, as a noun in apposition, for the Seaver family in recognition of support from the Seaver Institute for marine research.

Distribution
Type specimens of L. seaver were collected from Pohnpei, Micronesia. A single larva of what may be this species (98.2-99.5% similarity at CO1) was collected in Moorea, French Polynesia (BOLD: FPFLB281-12; GenBank: KJ967845.1; Hubert et al. 2014), but the taxonomic identity of the Moorea specimen could not be confirmed by the authors. Therefore, it is possible that adults of this species will be discovered in Moorea and other locations across the Pacific.

Taxon discussion
Luzonichthys seaver is distinct from all other species within the genus in life coloration. It is most similar in color to L. earlei (Fig. 2); however, it differs from that species in coloration of head, upper half of body, and dorsal and anal fins (yellow in L. seaver, compared with orange in L. earlei), and in the distinctive color pattern on the caudal fin (bright pink blotches on the base of both caudal lobes with bright yellow distally in L. seaver, compared with drab, diffuse orange blotches and pale yellow distal caudal lobes in L. earlei). We have examined enough individuals of L. earlei from many localities to confirm that these color characteristics do not vary signigicantly within that species. Morphologically, it differs from all other species except L. earlei in number of lateral line scales (63-64, compared with 51-60 or 65-78 for other species), and from all other species except L. whitleyi in caudal concavity (8.4-8.5 in HL, compared with 4.0-8.3 for other species). It further differs from all other species except L. earlei, L. waitei and L. taeniatus in number of gill rakers (8+18-19, compared with 7-10+20-23 for other species), and from L. williamsi and L. microlepis in number of anal-fin spines and rays (III, 7 compared with II, 9), as well as snout length, orbit diameter, and caudal peduncle depth (Table 3). Luzonichthys seaver is further distinct from L. williamsi in its body depth and pectoral fin length, and from L. taeniatus in snout length, caudal peduncle depth, and longest dorsal spine (Table 3). Overall, L. seaver is most similar morphologically to L. earlei and L. whitleyi; however, in addition to character differences outlined above, it can be further distinguished from these two species by caudal peduncle depth (both species) snout length (L. whitleyi), and head length (L. earlei) (  Table 3). Molecular data are not used for comparative purposes in this description because these data do not exist for any of the other species of Luzonichthys. The CO1 barcodes produced in this study represent the first sequences publicly available for this genus, aside from the afore mentioned and previously unclassified larval specimen from Moorea. Body depth in SL 3.9-4.6 3.6-4.1 4.1-4.4 3.7-4.0 3.3-3.8 4.15-5.0 5.2-5.4 Head length in SL 3.4-3.5 3.15-3.4 3.5-3.7 3.3-3.5 3.0-3.6 3.4-3.8 3.4-3.5
Comparison of selected morphological characters for species of Luzonichthys.