Aulopidae

Gomon, Martin F., Struthers, Carl D. & Stewart, Andrew L., 2013, A New Genus and Two New Species of the Family Aulopidae (Aulopiformes), Commonly Referred to as Aulopus, Flagfins, Sergeant Bakers or Threadsails, in Australasian Waters, Species Diversity 18, pp. 141-161 : 143

Indo-West Pacific Aulopidae

The aulopiform family Aulopidae is distributed throughout tropical and subtropical regions of the Atlantic and Pacific oceans, but appears to be absent from the Indian Ocean, except along the northwestern coast of Australia ( Gloerfelt-Tarp and Kailola 1984) and southern side of Indonesia (W. White pers. comm.). Of the family’s 16 nominal species, 9 in two genera are currently recognised as valid in the Pacific. With the increasing use of mitochondrial DNA for the identification of cryptic species (e.g., Ward et al. 2007; Smith et al. 2008; Zemlak et al. 2009) the technique was identified as an obvious tool for testing the identity of the presumed new Australasian species mentioned above, as well as other populations throughout the western Pacific that might similarly differ. The rapidly growing documentation of CO1 sequences for the Australasian region ( Ward et al. 2009) provided a comprehensive resource for such a comparison and similarly expanding tissue collections of world museums allowed many of the gaps in sequence data sets to be filled with minimal effort. It was noted in the course of aggregating sequences and tissues for this analysis that the identities for many of the sequences recorded in the BOLD database were questioned in some fashion (e.g., Hime cf. japonica , Hime sp. nov.).

Genetic results. The three best supported trees (TN93+G+I/NJ, TN93+G+I/ML and p-distace/NJ) have the same overall tree topology, differing only in some basal relationships. Rather than providing all three trees we have chosen to present the TN93+G+I/NJ tree ( Fig. 1 ) with bootstrap values exceeding 70% for all three genetic models at each relevant node.

All twelve terminal clades were supported by high bootstrap support with both ML and NJ (100%) methods. Infragroup variation was low and bootstrap values exceeded 85%, supporting morphological evidence that these clades represent single species. Sequence divergence values between the six species clades of Hime and two species of Leptaulopus ( Table 1) were low (0.072 –0.126 and 0.218 respectively), with higher values between genera ( Aulopus vs Hime 0.273 – 0.338; Hime vs Leptaulopus 0.246 –0.341; Hime vs Latropiscis 0.220 –0.273; Leptaulopus vs Aulopus 0.236 –0.274; Aulopus vs Latropiscis 0.333 –0.337). The highest within genus divergence was between the two species of Leptaulopus (0.218) also reflected in the considerable divergence of several meristic values for the two. Four of the six presumed species level clades in the terminal cluster comprise individuals verified as Hime curtirostris , H. formosanus , H. japonica , and the trans-Tasman new species of Hime described below. A fifth based on female specimens alone collected off northwestern Australia and southern Japan matches the description of H. diactithrix and is assumed to be that species. Despite Prokofiev’s (2012) reassessment of the validity of this species and resultant reassignment of it to subspecies status, genetic data implies a divergence equivalent to other recognised species of Hime and supports a hypothesis of a more distant relationship with H. formosanus within the genus than indicated. Recognition of the clade at species level is supported by morphological evidence in the form of relative dorsal fin ray lengths and associated fin form that are commensurate with characters identified below as diagnostic for the new species of Hime . The sixth clade represents a separate morphologically distinguishable species that is the subject of an ongoing study. All six agree with Thompson’s (1998) diagnosis of the genus Hime .

Although this analysis is not fully reliable from a phylogenetic perspective since it uses only a single, mitochondrial marker, the basal three aulopid clades each have considerably longer branches than those of Hime species , supporting a morphologically based hypothesis that they represent the separate genera discussed below. Vouchers for these three sequence clusters are identifiable as the Atlantic Aulopus filamentosus , the second new species described below and a taxon we regard as Latropiscis purpurissatus , a southern Australia endemic. The generic allocation for the last, though not examined further here, was endorsed by Shimizu and Yamakawa (1989) and Thompson and Stewart (2006) and is supported by morphological evidence.

Figures

Fig. 1. TN93 neighbour-joining tree of 59 COI sequences from 4 purported genera and 11 purported species of Aulopidae, as well as sequences for an outgroup species, Paraulopus nigripinnis. Percent bootstrap values are given for all well supported nodes (>70%), followed by bootstrap values for these nodes in a TN93 maximum likelihood and a p-distance neighbour joining tree. See text. Specimen numbers are registration numbers of vouchers or those of the Barcode of Life Database (BOLD, www.barcodinglife.org) or GenBank (www.ncbi.nlm.nih. gov).