Pomacentrinae

Tang, Kevin L., Stiassny, Melanie L. J., Mayden, Richard L. & DeSalle, Robert, 2021, Systematics of Damselfishes, Ichthyology & Herpetology 109 (1), pp. 258-318 : 287-288

Subfamily Pomacentrinae

This is the largest subfamily of the Pomacentridae . The clade, which received strong branch support (100% bootstrap), holds more than half of all previously recognized genera (15 of 29) and almost half of all currently recognized species (210 of 422). The subfamily can be divided into four clades, one of which is composed wholly of the anemonefishes. When revising the damselfish classification, Cooper et al. (2009) placed the Amphiprioninae in the synonymy of the Pomacentrinae but retained the Amphiprionini as a tribe. It was the only tribe they recognized in the subfamily. We follow Cooper et al. (2009) in recognizing this group as the tribe Amphiprionini . Furthermore, we hereby recognize the tribe Cheiloprionini , which includes Cheiloprion and its closest relatives: Chrysiptera sensu stricto, Dischistodus , Pomachromis , and separate lineages of species of ‘‘ Chrysiptera ’’ that fall outside of Chrysiptera sensu stricto. We recognize the clade that includes Hemiglyphidodon and its nearest relatives ( Acanthochromis , Altrichthys , Amblyglyphidodon , and Neoglyphidodon ) as the tribe Hemiglyphidodontini . We recognize the tribe Pomacentrini as including Amblypomacentrus , Neopomacentrus , Pomacentrus , Pristotis , Teixeirichthys , and the remaining species of ‘‘ Chrysiptera .’’

There is a potential osteological synapomorphy for Pomacentrinae reported in the literature ( Emery and Allen, 1980; Randall et al., 1981): the interpenetration of pterygiophores into the spaces between the corresponding neural spines. This character has been discussed in the literature with different notation schemes ( Emery and Allen, 1980; Randall et al., 1981; Randall, 1994, following Ahlstrom et al., 1976). We use the notation format of Emery and Allen (1980) herein. Emery and Allen (1980) observed two patterns in pomacentrids: (1) first dorsal pterygiophore penetrates the space between the second and third neural spines, two pterygiophores penetrate the space between the third and the fourth neural spines, with a single pterygiophore in each space thereafter (coded as ‘‘0,0,1,2,1,1...’’); (2) first two dorsal pterygiophores penetrate the space between the second and third neural spines, with a single pterygiophore in each space thereafter (coded as ‘‘0,0,2,1,1,1...’’). The (0,0,1,2,1,1) pattern is found in Abudefduf , Chromis , Dascyllus , Lepidozygus , Mecaenichthys , Microspathodon , Plectroglyphidodon , and Stegastes (Emery, 1980; Emery and Allen, 1980: table 1). Tang (2002) reported the character state in two additional genera, Hypsypops and Parma . Cooper et al. (2014: fig. 4a, b) illustrated Similiparma with that condition. Emery and Allen (1980) recorded the (0,0,2,1,1,1) pattern in species of Acanthochromis , Amblyglyphidodon , Amphiprion , Cheiloprion , Chrysiptera , Dischistodus , Hemiglyphidodon , Neoglyphidodon (as Paraglyphidodon ), Neopomacentrus , Pomacentrus , Premnas , Pristotis , and Teixeirichthys . Based on the distribution of character states, the (0,0,2,1,1,1) pattern could be a synapomorphy for the subfamily Pomacentrinae . The condition of this character is unknown in Altrichthys , Amblypomacentrus , Azurina , Nexilosus , and Pomachromis . Based on their respective positions in the tree ( Fig. 1 ; Supplemental Fig. 1 ; see Data Accessibility), Azurina and Nexilosus are predicted to have the (0,0,1,2,1,1) pattern, whereas Altrichthys , Amblypomacentrus , and Pomachromis are predicted to have the (0,0,2,1,1,1) pattern.

There are karyotype data reported in the literature that may support the monophyly of the subfamily. Damselfishes are characterized by large variations in chromosome numbers and fundamental numbers ( Takai and Ojima, 1995). A diploid number of 2n ¼ 48, with a fundamental number of NF ¼ 48 (all chromosomes acrocentric), is considered to be the ancestral state for the family, with most pomacentrids exhibiting those conditions (Alvarez et al., 1980; Takai and Ojima, 1987, 1991; Arai, 2011). Possession of 48 acrocentric chromosomes appears to be the ancestral state for teleosts as a whole ( Ohno and Atkin, 1966; Ohno, 1974; Takai and Ojima, 1991; Mank and Avise, 2006). Increases in the conserved NF of 48 have been observed in putative pomacentrines (e.g., Ojima, 1983; Klinkhardt et al., 1995; Molina and Galetti, 2004b; Arai, 2011; Takai, 2011; Tanomtong et al., 2012; Takai and Kosuga, 2013; Supiwong et al., 2015). These deviations in fundamental number are hypothesized to be the result of pericentric inversions ( Ojima, 1983; Takai and Ojima, 1987, 1991; Molina and Galetti, 2004b; Getlekha et al., 2018). Based on the distribution of fundamental numbers across pomacentrids ( Klinkhardt et al., 1995; Arai, 2011), a high fundamental number may be synapomorphic for the subfamily Pomacentrinae . However, this character is not completely consistent because high fundamental numbers (NF 78) appear in Stegastes sensu lato ( Ojima, 1983; Molina and Galetti, 2004b; Galetti et al., 2006; Arai, 2011). Conversely, low values (NF ¼ 48) are seen in some pomacentrines (e.g., Chrysiptera cyanea , Pomacentrus auriventris , P. coelestis , P. similis ; Arai and Inoue, 1976; Ojima, 1983; Takai and Ojima, 1987, 1999; Getlekha et al., 2018).

Egg morphology may also distinguish members of the Pomacentrinae from the other subfamilies. Muñoz-Cordovez et al. (2019: table S1) found that all surveyed pomacentrines share a capsule-shaped egg, whereas other subfamilies all have ellipsoid eggs, except for one species of Microspathdontinae ( Stegastes leucostictus ) that also possesses capsule-shaped eggs. Capsule eggs appear to give rise to larvae that show a wider range of development at the time of hatching compared to larvae from ellipsoid eggs ( Muñoz-Cordovez et al., 2019). Pomacentrine larvae tend to be more well developed than those of other subfamilies, which Muñoz-Cordovez et al. (2019) suggested could be tied to the higher temperatures (21–288C) in which the eggs develop.

Figures

FIG. 1. The phylogenetic relationships of damselfishes (Teleostei: Pomacentridae): (A) outgroup taxa; (B) subfamilies Microspathodontinae and Glyphisodontinae; (C) subfamily Chrominae; (D) subfamily Pomacentrinae (part I); (E) subfamily Pomacentrinae (part II). The phylogeny is based on the maximum-likelihood topology with the best log likelihood score (ln L ¼ –45,4518.728) recovered from ten independent maximum-likelihood analyses of a data matrix composed of 462 taxa and 6,865 nucleotides. Bootstrap values from 1,000 ultrafast replicates are displayed for each node