Phyllopteryx dewysea, Josefin Stiller, Nerida G. Wilson & Greg W. Rouse, 2015

Josefin Stiller, Nerida G. Wilson & Greg W. Rouse, 2015, A spectacular new species of seadragon (Syngnathidae), Royal Society Open Science 2 (40458), pp. 1-12 : 7-10

Phyllopteryx dewysea n. sp.

( figure 1 , figure 2 a–f, figure 3 c, tables 2 and 3 , electronic supplementary material figure S2 a, b and videos S1–S2).

4.4.1. Holotype

The holotype repository is the Western Australian Museum, Perth: WAM P33223.002, as Phyllopteryx taeniolatus , 240 mm TL, male with brood attached; eggs removed for DNA extraction, tail clipped. The species has been registered with Zoobank under the following LSID: BEF4 C635-D5DD- 4F 70-99B6- 88157AA88C7C.

4.4.2. Type locality

Australia, Western Australia, Recherche Archipelago, east of Middle Island , trawled at 51 m, Marine Futures Survey 2007, station MF-MI-007 , 10 October 2007, 34° 0 1.589′0 S, 123° 21.55′0 E to 3 4°0 1.30′ S, 123° 21.42′ E.

4.4.3. Paratypes

Three paratypes are designated based on morphological similarity to the holotype ( table 3 and electronic supplementary material, file S1). CSIRO Marine and Atmospheric Research, ANFC C2269 and C2270, as Phyllopteryx lucasi (= taeniolatus ), two specimens, 236 and 259 mm TL, sex undetermined; trawled west of Garden Island , Western Australia, 32° S, 115° E (coordinates approximated), 72 m, May 1956.

WAM P660 , as Phyllopteryx foliatus , one specimen, 221 mm TL, sex undetermined; beachwashed onto Cottesloe Beach , Western Australia, 31° 59′ S, 115° 45′ E, August 1919 .

4.4.4. Etymology

Named for Mary ‘Dewy’ Lowe, for her love of the sea and her support of seadragon conservation and research, without which this new species would not have been discovered.

4.4.5. Diagnosis

Eighteen trunk segments. Head crest without appendage. Pectoral area enlarged (pa in figure 2 b, e). Dorsally enlarged spine on trunk ring 11 pointed forward (ds in figure 2 b). Paired enlarged ventral spines on rings 8 and 17 ( figure 3 c). Body deepest on ring 12, behind dorsal spine. Spines on lateral trunk ridge not continuous with lateral tail ridges ( figure 2 c).

4.4.6. Brief description of holotype

Preserved colour light brown. Live colour ruby red, with pink vertical bars on each trunk segment and light markings on the snout ( figure 2 a). Enlarged spines dorsally on neck and trunk ring 11; ventrally on rings 3, 8, 17 (arrows in figure 2 c; see also videos S1–S2 included in the electronic supplementary material). Presence and shape of dermal appendages on enlarged spines unknown. Lateral trunk ridges

not confluent with lateral but with inferior tail ridges. Trunk dorsally forming pronounced arch, highest point ring 12, behind enlarged dorsal spines ( figure 3 c). Fin rays: pectoral 22; dorsal unknown; anal 4.

4.4.7. Distribution and bathymetry

The type locality (arrow in map of figure 1 ) at 5 0+ m shows a complex habitat of a mixed reef and sandy habitat [ 29, 30]. Two paratypes were collected from the continental shelf near Perth (72 m, circle in figure 1 ); the habitat at this site is unknown. The fourth paratype, collected at Cottesloe, Perth, does not have depth data, as it was washed up on the beach.

4.4.8. Remarks

The placement of this species within Phyllopteryx was informed by the phylogeny of seadragons ( figure 1 ). The new species lies as the sister group to Phyl. taeniolatus and this does not allow for its inclusion within the other seadragon genus, Phycodurus . We made the decision to place it within Phyllopteryx rather than erect a new genus, as this provides information about the closer relationship of Phyl. dewysea with Phyl. taeniolatus than with Phyc. eques .

An expanded description of the type series of Phyl. dewysea , of Phyl. taeniolatus and Phyc. eques , including detailed comparisons, can be found in the electronic supplementary material, file S1.

Figures

Figure 1. Distribution and phylogenetic relationships of the three seadragon species. The range of the leafy seadragon is shown in gold, the common seadragon in blue and the type locality of the new seadragon Phyllopteryx dewysea n. sp. is indicated by the red arrow. The red circle represents the collection sites of the three paratypes. The maximum-likelihood tree is based on the partitioned dataset (4416 bp). Numbers next to the nodes indicate bootstrap (top) and jackknife (bottom) values; full support is indicated by white circles.

Figure 2. Holotype of the new seadragon Phyllopteryx dewysea n. sp. (a) On-deck shortly after being trawled; (b) preserved, with tip of tail and eggs removed for DNA extraction; pa pectoral area; ds facing dorsal spine; (c – f) three-dimensional scan generated by µ CT; (c) outer bony plates, arrows pointing to different enlarged spines; (d) left half of the plates removed to reveal parts of the skull, pectoral girdle and spine (in white); (e) ventral view of the enlarged pectoral area; (f) detail of the trunk region. Scale bars, 1 cm.

Figure 3. Comparison of the skeleton of the three species of seadragons. X-ray radiographs of (a) the leafy seadragon Phycodurus eques, SIO 04 - 28; (b) the common seadragon Phyllopteryx taeniolatus, SIO 84 - 300; (c) Phyllopteryx dewysea n. sp., holotype WAM P 33223.002. Scale bars, 1 cm.

Tables

Table 3. Morphometric measurements for the three seadragon species. Values for Phyllopteryx dewysea are given separately for the holotype and as ranges for the three paratypes. Proportions are given as % of the total length (TL), head, or snout length. The tail length of the holotype was measured from the photograph (figure 1 a) as the tail is incomplete in the preserved specimen.

	Phycodurus eques (n = 25)	Phyllopteryx taeniolatus (n = 20)	Phyllopteryx dewysea n. sp. (holotype | three paratypes)
total length (TL, mm)	218–401	238–427	240 | 221–259
trunk length (mm)	67–114	70–135	67 | 61–79
tail length (mm)	114–221	98–234	111 | 92–123
proportions (%)
trunk length: TL	25–42	24–34	28 | 28–31
tail length: TL	45–69	42–58	46 | 41–48
head length: TL	18–33	17–29	26 | 22–31
snout length: head length	5 3–7 7	6 1–7 2	6 8 | 65–74
snout depth: snout length	11–20	7–13	7 | 7–10
orbital diameter: head length	10–13	8–13	12 | 10–13
postorbital length: head length	23–36	11–28	20 | 18–24
neck depth: TL	4–11	3–7	5 | 3–4
trunk depth 8th segment: TL	8–18	4–14	8 | 7–9
trunk depth 11th segment: TL	8–17	6–13	11 | 9–12
trunk depth preanal segment: TL	6–12	4–9	9 | 6–8