Hippocampus spinosissimus, Weber 1913

Sara A. Lourie, Riley A. Pollom & Sarah J. Foster, 2016, A global revision of the Seahorses Hippocampus Rafinesque 1810 (Actinopterygii: Syngnathiformes): Taxonomy and biogeography with recommendations for further research, Zootaxa 4146 (1), pp. 1-66 : 40

H. spinosissimus Weber 1913

English common names. Hedgehog Seahorse.

Synonyms. H. alatus Kuiter 2001 , H. arnei Roule 1916 (in part), H. curvicuspis Fricke 2004 (in part), H. queenslandicus Horne 2001 , H. semispinosus Kuiter 2001 .

Syntypes. ZMA 104.665 (2).

Type locality. Sapeh Strait , Indonesia.

Distribution. Australia (north), Cambodia, India, Indonesia, Malaysia, Myanmar, Philippines, Singapore, Sri Lanka, Taiwan, Province of China, Thailand, Viet Nam.

Notes. The type specimens of H. spinosissimus are surprisingly small, yet they are males with fully developed pouches. They also have clear nose spines, double cheek spines, and all body spines are approximately equally developed. A third specimen labelled as ‘type’ ( ZMA 114.473 ) had single cheek spines. Lourie et al. (1999) used this name to refer to spiny seahorses from across Southeast Asia, even though the latter frequently lacked a nose spine . No genetic data are available from the type specimens. Morphological and genetic data do not support the distinctness of H. queenslandicus nor H. semispinosus from what is understood as H. spinosissimus by Lourie et al. (1999) ( Teske et al. 2007c; BOLD 2016 ; Appendix N; see also Zhang et al. 2014). Admittedly there exists variation in spine development and colour pattern among H. spinosissimus specimens and genetic data indicate that haplotype diversity is high, with three major lineages, two of which are broadly sympatric and one that is restricted to the central Philippines (Lourie et al. 2005). However, the genetic divergence among specimens of H. spinosissimus examined from Australia, Malaysia and the Philippines is only 0.82% (648bp, CO1) ( BOLD 2016 ), and the average cytochrome b sequence divergence among 172 specimens from 29 populations is only 1.3% (Lourie et al. 2005). At present we suggest that the variation represents polymorphism within a single species, rather than different species, however further investigation is warranted. Kuiter (2009) and Allen & Erdmann (2012) identify spiny Southeast Asian seahorses variously as H. arnei (see comments under H. barbouri ), H. alatus , H. moluccensis (see comments under H. kuda ), and H. polytaenia . The illustration of H. polytaenia ( Bleeker, 1983) does show markings and moderately developed spines that are reminiscent of H. spinosissimus , however the type specimens conform to H. kuda (SL pers. obs.). Hippocampus alatus is tentatively synonymised here on the basis of morphological similarity, pending further work (especially genetics) (see Appendix N).