Tuesday, December 27, 2016

[Ichthyology • 2016] Tosanoides obama • A New Basslet (Perciformes, Percoidei, Serranidae) from Deep Coral Reefs in the Northwestern Hawaiian Islands


Tosanoides obama 
Pyle, Greene & Kosaki, 2016  


Abstract

The new species Tosanoides obama is described from two specimens collected at a depth of 90–92 m off Kure Atoll and Pearl and Hermes Atoll, Northwestern Hawaiian Islands. It differs from the other two species of this genus in life color and in certain morphological characters, such as number of pored lateral-line scales, pectoral-fin rays, snout length, anterior three dorsal-fin spine lengths, dorsal-fin profile, and other characters. There are also substantial genetic differences from the other two species of Tosanoides (d ≈ 0.10 in mtDNA cytochrome oxidase I). The species is presently known only from the Northwestern Hawaiian Islands within the Papahānaumokuākea Marine National Monument.

Keywords:  Mesophotic Coral Ecosystem, Closed-Circuit Rebreather, Endemic, Papahānaumokuākea Marine National Monument, President Obama


Figure 1. Holotype of Tosanoides obama (BPBM 41315), collected at a depth of 90 m off Kure Atoll, Northwestern Hawaiian Islands. Photo by R. L. Pyle. 

Diagnosis:  A species of Tosanoides (sensu Katayama & Masuda, 1980) distinguished by the following combination of characters: fourth or fifth dorsal spine the longest, dorsal-fin soft rays 17; anal-fin soft rays 8; pored lateral-line scales 33 or 34; head 2.9–3.0 in SL; body depth 2.8–2.9 in SL; color in life pink or yellowish pink on head and body, slightly darker dorsally fading ventrally; snout and region immediately dorsal to eye bright yellow, with a thin bright yellow band extending dorsally on either side of nape; a thin bright yellow horizontal stripe extending horizontally from posterior middle edge of eye posteriorly across most of operculum, continuing as a series of irregular oblong spots on midline of body from just posterior to gill opening to a point approximately one-fourth to one-half of pectoral fin; a second thin bright yellow stripe extending posteriorly from lower jaw across maxilla just ventral to eye and continuing horizontally across operculum and base of pectoral fin; dorsal fin pink or yellowish pink with darker pink regions on membranes, and a bright magenta margin extending from tip of first dorsal fin posteriorly on anterior half of soft dorsal fin; males with a large circular ocellate spot covering posterior one-third of soft dorsal fin, bluish magenta on perimeter and dark red with faint yellow stripes centrally; anal and pelvic fins magenta or yellow; caudal fin translucent yellow, more pale and translucent medially and distally, with bright magenta margins extending along margins of both lobes.

Figure 4. Holotype of Tosanoides obama (upper left) alongside presumed female (lower right, not collected) immediately prior to collection of the holotype, at a depth of 90 m off Kure Atoll, Northwestern Hawaiian Islands. Both fish retreated into the same hole moments after this image was captured. Cropped frame from video by R. L. Pyle. 


Etymology:  We name this species obama (a noun in apposition) in honor of Barack H. Obama, 44th President of the United States, in recognition of his efforts to protect and preserve the natural environment, particularly through his decision to expand the Papahānaumokuākea Marine National Monument several weeks after the discovery of this new species.

Discussion
Tosanoides obama is another example of several new fish species that have been discovered on deep coral reefs over the past several decades, mostly involving the use of modern mixed-gas closed-circuit rebreather diving technology (Pyle 1996, 2000). In recent years there has been increased attention focused on mesophotic coral ecosystems (MCEs), coral-reef habitat at depths of approximately 30–150 m in tropical regions worldwide (Hinderstein et al. 2010, Baker et al. 2016). Many more new species of fishes and other reef-associated marine organisms are likely to be discovered as a result of continued exploratory work in this poorly documented environment.

The fish subfamily Anthiinae (Anthiadides Poey, 1861, type genus Anthias Bloch, 1792, stem Anthi-), is a homonym of the beetle subfamily Anthiinae (Anthies Bonelli, 1813, type genus Anthia Weber, 1801, stem Anthi-). According to Article 55.3 of the International Code of Zoological Nomenclature (ICZN 1999), homonymous family-group names in current use based on similar (but not identical) genus-group names must be referred to the Commission for a ruling to remove homonymy. A case is currently in preparation to formally resolve this homonymy through application to the ICZN. Until an Opinion is issued, we follow van der Laan et al. (2014, 2016) and Carvalho-Filho (2016) in using the spelling “Anthiadinae” to represent the subfamily for this new species, instead of the more commonly used (but homonymous) spelling “Anthiinae”.


Richard L. Pyle, Brian D. Greene and Randall K. Kosaki. 2016. Tosanoides obama, A New Basslet (Perciformes, Percoidei, Serranidae) from Deep Coral Reefs in the Northwestern Hawaiian Islands. ZooKeys 641: 165-181. DOI:  10.3897/zookeys.641.11500

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