Hippocampus pontohi Lourie &amp; Kuiter 2008, sp. nov.
Creators: name: Lourie, Sara A.
name: Kuiter, Rudie H.
Publisher: name: Zenodo
Year: 2008
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Syngnathiformes
Syngnathidae
Hippocampus
Hippocampus pontohi

description: <i>Hippocampus pontohi</i> sp. nov. <b>Type material.</b> Holotype: MZB 13593 (16.9 mm, male), Lekuan II, Bunaken, North Sulawesi, Indonesia (1 o 36'5"N 124 o 45'56"E), 16 m depth, among algae/hydroid crops, 18 July 2003, M. Aw. Figures 2A and 3A. Paratypes: MZB 13596 (16.8 mm, male), Negeri / Manado Tua, North Sulawesi, Indonesia (1 o 37'28"N 124 o 42'54"E), 12 m depth, among byrozoans/hydroids, 22 July 2004, R. Lahengko. MZB 13597 (16.6 mm, male?), Alung Banua, Bunaken, North Sulawesi, Indonesia (1 o 37'7"N 124 o 45'30"E), among byrozoans/ hydroids, 22 July 2004, R. Lahengko. <b>Diagnosis.</b> Extremely small size (height 14 mm, standard length 17 mm); 12 trunk rings; 26–28 tail rings; reduced ossification of inferior and ventral trunk ridges; 14 dorsal fin rays; 9–10 pectoral fin rays; small or absent anal fin; brooding area in males anterior to anus; medium length snout which lacks a bulbous tip; raised, angular coronet; fused (or almost fused in holotype) gill-openings on midline behind coronet supported by raised cleithral girdle; scattered tubercles on trunk and tail; distinctive branching filaments (usually red in life) attached to the enlarged superior trunk ridge spine of the fifth trunk ring; white colour, occasionally with yellow or pink especially along the dorsal surface, with fine red lines on the trunk, and reddish transverse bands across the tail. <b>Comparison.</b> <i>Hippocampus pontohi</i> is most similar to <i>H. colemani</i> and is primarily separated from the latter species on the basis of tail ring counts (26–28 in <i>H. pontohi</i>, versus 28–30 in <i>H. colemani</i>), raised angular coronet, the following proportions: OD:HL (22.4–26.6% vs 18.6–18.9%), TD9:SL (11.0–15.7% vs 18.9–19.5%) and overall size (SL 16.6–16.9 mm vs 26.5–27.3 mm). <i>Hippocampus pontohi</i> is much less robust overall than <i>H. bargibanti</i> and lacks the latter’s very large tubercles and bulbous snout tip. It can be further distinguished from <i>H. bargibanti</i> by body colour (white vs purple with red tubercles, or grey with yellow/orange tubercles), fewer tail rings (26–28 vs 31–33), proportionally larger head (HL:SL 20.4–23.9% in <i>H. pontohi</i> vs 14.8–19.5% in <i>H. bargibanti</i>), less pronounced coronet (CH:HL 45.1–50.7% vs 46.1–64.1%), narrower snout (SnD:SnL 79.2–87.7% vs 82.2–144.1%), larger orbit (OD:HL 22.4–26.6% vs 14.2–24.0%), smaller post-orbital (PO:HL 49.0–53.5% vs 51.6–63.3%), longer trunk length (TrL:SL 32.4–33.9% vs 25.7–29.5%) and shorter tail length (TaL:SL 43.7–45.8% vs 53.3–57.1%). It can be distinguished from <i>H. denise</i> by its body colour (white vs orange), deeper head (HD:HL 59.3–61.5% in <i>H. pontohi</i> vs 41.1–55.7% in <i>H. denise</i>), shorter snout (SnL:HL 22.6–24.4% vs 27.1–38.7%), larger orbit (OD:HL 22.4–26.6% vs 18.8–23.5%), larger post-orbital (PO:HL 49.0–53.5% vs 39.1–45.2%), longer trunk (TrL:SL 32.4–33.9% vs 23.1–31.7%), shorter tail (TaL:SL 43.7–45.8% vs 47.4–57.2%) and deeper body (TD9:SL 11.0–15.7% vs 4.1–15.5%). Both sexes of <i>H. pontohi</i> have rounded trunk profiles in comparison to female <i>H. denise’s</i> narrow trunk. Furthermore, <i>H. pontohi</i> has a more pronounced coronet, fewer tail rings (26–28 vs 27–30) and fewer pectoral fin rays (9–10 vs 10–11). <i>Hippocampus pontohi</i> can be differentiated from H. minotaur most clearly on the basis of meristic values: TrR 12 vs 8–9, TaR 26–28 vs 41, PF 9–10 vs 11 and DF 14 vs 7–9. It also has a significantly shallower head (HD:HL 59.3–61.5 vs 75.1–80.2%), longer trunk (TrL:SL 32.4–33.9 vs 18.4–24.7%), shorter tail (TaL:SL 43.7–45.8 vs 56.0–66.6%) and longer dorsal fin base (DL:SL 7.3–8.0 vs 1.5–2.4%). <b>Description.</b> In addition to the characters given in the diagnosis: head length 20.8% (20.3–23.9%) in SL, and head depth 59.3% (60.8%–61.5%) in HL; snout length 24.4% (22.6–22.7%) in HL without bulbous tip, and snout depth 87.7% (79.2–85.5%) in SnL; orbital diameter 22.4% (22.9–26.6%) in HL; post-orbital length 50.9% (49.0–53.5%) in HL; frontal bone strongly raised posteriorly to form a sharply angled coronet (Figure 2A); pectoral fin-base raised; pectoral fin rays 10 (9–10). Trunk rings (TrR) 12, dorsal surface of TrR1 and TrR2 expanded laterally (but without spines); trunk length 33.6% (32.4–33.9%) in SL; trunk depth just anterior to dorsal fin base 15.7% (11.0–13.8%) in SL; dorsal fin base strongly raised and angled with respect to trunk (highest posteriorly); dorsal fin base starting immediately posterior to 9 th trunk ring and ending immediately posterior to 12 th trunk ring (covering 3+0 rings); dorsal fin rays 14; no external pouch visible in males, developing young housed entirely within trunk region anterior to the anus; anal fin not visible in any of the type specimens; first tail ring quadrangular; tail rings 26 (27–28); tail length 45.6% (43.7–45.8%) in SL. Sexual dimorphism appears to be limited to differences in the genital region: males with vertical pouch slit, females with slightly raised, circular genital opening (see Lourie &amp; Randall, 2003 for diagram). Body ornamentation: prominent rounded spine above each eye, on midline of snout between eyes, and on either side of head below coronet; shoulder spine at base of pectoral fin; cheek spine; orbital ring with 12 small spines of alternating colours (brown/white); unbranched filament attached to anterior part of coronet in MZB 13596, other specimens without head filaments; greatly enlarged rounded spines on superior ridge of 5 th trunk ring to which distinctive branched red filaments are attached; greatly enlarged rounded spine on superior ridge of 12 th trunk ring and smaller, but still prominent, rounded spines on the lateral ridge of 8 th trunk ring; small, rounded spines on the inferior ridges of 8 th, 9 th, 10 th and 11 th trunk ring (visible as tiny spines in MZB 13596). Enlarged rounded spines on superior ridge of tail align with bands of colour across 5 th, 8 th (or 9 th), 12 th, and 15 th (or 16 th) rings. <b>Colour in life:</b> white, pinkish or yellowish-white (slightly darker on dorsal surface) with fine red lines tracing the superior trunk ridge and extending ventrally in broad loop around 5 th and 8 th trunk ring; 3–5 red transverse bands across tail that correspond to the position of enlarged superior tail ridge spines; scattered dark markings on head; sporadic dark markings on ventral midline between horizontal trunk ridges; dark patch immediately posterior to anus (Figure 4A). Colour in alcohol: pale cream with mid-ventral markings and bands on tail retained but muted. Dorsal and pectoral fins with dark spots in line near dorsal margin (Figure 3A). <b>Discussion.</b> Two other specimens examined: NMV 24979 -001 (17.3 mm, male; 16.6 mm, female), Milne Bay, Papua New Guinea (10 o 20'S 150 o 25'E), 12 m depth, in <i>Halimeda</i>, November 2002, L. Maleta are tentatively identified as <i>H. colemani</i> on the basis of tail ring number, lack of raised coronet, TaL:SL, HD:HL, as well as their geographic locality. The specimens are, however, much smaller than the type specimens of <i>H. colemani</i> and have other proportions that are more similar to <i>H. pontohi</i> <b>sp. nov.</b> than to <i>H. colemani.</i> It is possible that future research will reveal that <i>H. pontohi</i> and <i>H. colemani</i> represent a cline of variation within a single species. In the interests of clarity, and given the present lack of additional data, comparisons in the text descriptions and Tables 1 to 3 are restricted to the type specimens of <i>H. colemani.</i> <b>Etymology.</b> This species is named in honour of Hence Pontoh, the Indonesian dive guide who first brought these pygmy seahorses to our attention. <b>Distribution and ecology.</b> <i>Hippocampus pontohi</i> has been observed on the coralline algae <i>Halimeda</i>, as well as on the hydroid <i>Aglaephenia cupressina</i> (Müller and Severns, <i>pers. comm.</i>). Severns noted it particularly in areas where <i>Halimeda</i> is growing on reef walls. It has been recorded at a number of areas in Indonesia (Bunaken, Cape Sri, Sorong, Wakatobi, Lembeh Straits), at depths of between 11–25 m particularly on vertical walls or in rock fissures (Müller, <i>pers. comm.</i>). See figure 5A for map. <i>Hippocampus pontohi</i> is commonly found in pairs and, like <i>H. denise</i>, is relatively active (Müller, <i>pers. comm.</i>). Two of the specimens examined were pregnant (MZB 13593 and MZB 13596) and each contained approximately 11 embryos. Both were collected in July.
description: Published as part of <i>Lourie, Sara A. &amp; Kuiter, Rudie H., 2008, Three new pygmy seahorse species from Indonesia (Teleostei: Syngnathidae: Hippocampus), pp. 54-68 in Zootaxa 1963 (1)</i> on pages 59-61, DOI: 10.11646/zootaxa.1963.1.4, http://zenodo.org/record/5241811
description: {"references": ["Lourie, S. A. &amp; Randall, J. E. (2003) A new pygmy seahorse, Hippocampus denise (Teleostei: Syngnathidae) from the Indo - Pacific. Zoological Studies, 42, 284 - 291."]}