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.