Altrichthys alelia Bernardi, Longo, & Quiros

Bernardi, Giacomo, Longo, Gary C. & Quiros, T. E. Angela L., 2017, Altrichthysalelia, a new brooding damselfish (Teleostei, Perciformes, Pomacentridae) from Busuanga Island, Philippines, ZooKeys 675, pp. 45-55 : 45-47

Altrichthys alelia Bernardi, Longo, & Quiros sp. n.

Type locality.

San José, Busuanga Island, Philippines, 12.1911°N; 120.1022°E.

Holotype.

PNM 15195; 54.7 mm S.L., San José, Busuanga Island, Philippines, 12.1911°N; 120.1022°E, 3m, hand net, G. Bernardi, G. Longo and A. Quiros (Figures 1, 2).

Paratypes.

CAS 241438, 3 adult specimens, SL 51.0-54.1 mm; CAS 241439, 8 juvenile individuals, SL 13.9 - 19.7mm. Both lots collected with Holotype, Busuanga Island, Philippines, 3m, hand net, G. Bernardi, G. Longo and A. Quiros.

Comparative material.

Altrichthys azurelineatus . Holotype: USNM 89957 (one specimen, Uson Island), Paratypes USNM 96398 (one specimen Tara island), USNM 96425 (one specimen, Tara Island). Altrichthys azurelineatus 5 specimens from Uson Island, A. curatus 5 specimens from Uson Island and Sangat Island.

Diagnosis and description.

A species of Altrichthys distinguished by the following combination of characters: dorsal rays XIV, 13-14; anal rays II, 15, tubed lateral line scales 14-15 (Table 1); preorbital and sensory pores small and numerous, usually more than 30, adult coloration in life pale green on upper half grading to white on lower part; iris silvery; pale yellow to gold outer margin of dorsal and upper and lower edges of caudal fin. Fins mainly white to translucent. Juveniles up to 16mm in length are mostly white with a prominent yellow stripe along the lateral line (Figure 3). Adults are generally of the same size as other Altrichthys adults, approximately 70-80mm TL. Altrichthys alelia differs from A. curatus by having long filaments at the trailing edges of the dorsal and caudal fins, and from A. azurelineatus by lacking any black lining of the outer edges of dorsal and caudal fins. These black margins are represented by yellow/gold margins in A. alelia (Figure 4). Pored lateral line scales easily distinguish A. curatus (17-18) and A. azurelineatus (10-14). Counts for A. alelia are most similar to and overlap A. azurelineatus counts, but exhibit a higher mode (15).

In addition, Sanger sequencing results show that Altrichthys alelia individuals form a group most closely related to, but distinct from, A. azurelineatus (Figure 5). Altrichthys alelia sequences differed from their closest relative A. azurelineatus by one fixed difference at the nuclear locus RAG2. For mitochondrial markers, Altrichthys alelia sequences differed from A. azurelineatus by 13 and 15 fixed mutations for cytochrome oxidase I and control region markers, respectively, thus corresponding to a Kimura-2 sequence divergence of 2.3% and 5.9% respectively. These divergences are consistent with values obtained in other sister species of fish ( Ward et al. 2005). RAD DNA sequencing results were also consistent with A. alelia and A. azurelineatus being distinct species and more closely related to each other than either are to A. curatus (Table 2). Indeed, RAD sequencing generated 8383 variable SNPs for the 5 sequenced individuals (2 A. alelia , 1 A. azurelineatus , 2 A. curatus ). Of those 8383 SNPs, 1584.5 (18.9%) showed differences between A. alelia and A. azurelineatus ; while 7224.5 (86.2%) and 6495 (76.4%) showed differences between A. curatus and A. alelia and between A. curatus and A. azurelineatus , respectively (Table 2).

Distribution.

Known from northern Busuanga Island at San José, Palawan Province, Philippines (Figure 2).

Habitat.

Collected off live and extensive thickets of corals mostly Porites cylindrica .

Etymology.

The name Altrichthys alelia derives from the combined first names of Alessio Bernardi and Amalia Bernardi, who greatly helped during field-work on Altrichthys .

Common name.

We suggest Alelia’s damselfish as a literal translation of the scientific name.