Microphis arrakisae, Haÿ & Mennesson & Dahruddin & Sauri & Limmon & Wowor & Hubert & Keith & Lord, 2024

Haÿ, Vincent, Mennesson, Marion I., Dahruddin, Hadi, Sauri, Sopian, Limmon, Gino, Wowor, Daisy, Hubert, Nicolas, Keith, Philippe & Lord, Clara, 2024, A new freshwater pipefish species (Syngnathidae: Microphis) from the Sunda shelf islands, Indonesia, Zootaxa 5536 (1), pp. 139-152 : 148-150

Microphis arrakisae sp. nov.

urn:lsid:zoobank.org:act:DFF608FB-743F-49F5-AEED-2738B7CEF2EC

( Table 3; Figures 1 ; 2; 4; 5; 6)

Holotype. MZB.26973 (tag BIF-4074), male, 107.93 mm SL, Indonesia, Lombok , 3 Feb. 2011, Hubert et al. Coll.

Paratypes. MZB.26974 (tag BIF4073), male, 99.13 mm SL, Indonesia, Lombok , 3 Feb. 2011, Hubert et al. Coll. MNHN-IC-2023-0318 (tag BIF3775, BIF3776), 1 male, 1 female, 93.86–100.94 mm SL, Indonesia, Lombok , 27 Mar. 2011, Hubert et al. Coll .

Diagnosis. 35–38 dorsal fin rays, and 29–30 tail rings. Body coloration mainly yellowish; distribution in West Indonesia (Java, Bali, Lombok).

Description. The body is smooth and tapered. Dorsal-fin rays 35–38, caudal fin rays 9, pectoral-fin rays 17–18. Trunk rings 17, tail rings 29–30, subdorsal trunk rings 0.5–1, subdorsal tail rings 7–7.5 and total subdorsal rings 8–8.5. Anal fin is atrophied and located just before the urogenital papilla. Pelvic fins absent. Head length 9 to 10% of SL. Short (4% of SL) and thin (less than 1% of SL). Size up to 107.93 mm SL. Operculum with a complete longitudinal ridge with supplemental ridges below the longitudinal ridge. Pectoral-fin base with a complete distinct ridge. Two distinct superimposed lateral snout ridges from the terminus of the mouth to the behind of the eye ( Figure 5.A ). Scutella keeled on the side of the tail and often keeled on the side of the posterior rings of the trunk. Discontinuous supraorbital ridge from the naris to the near end of the operculum ( Figure 5.A ). Complete supraopercular ridge over the entire length of the operculum ( Figure 5.A ). Continuous ridge present dorsally on midline of snout: ridge present on supraoccipital, anterior and posterior nuchal plates, first trunk ring, and anterior portion of the second trunk ring ( Figure 5.B ). Lateral trunk and tail ridges, and superior trunk and tail ridges are discontinuous with lateral trunk ridge confluent with the inferior tail ridge under the dorsal fin. Section of the trunk V-shaped while section of the tail is square-like. The male brood pouch is located under the trunk beginning on the first trunk ring and ending at the urogenital papilla. Pouch plates slightly convergent. Pouch folds are absent: Eggs are small in which a single layer are deposited in three to four rows of around a hundred eggs per pouch.

Coloration in vivo. Male and female body yellowish, no sexual dichromatism ( Figure 3 ). Some individuals may have a dark stripe on the side of the snout and above the operculum. The pectoral, anal and dorsal fins are translucent without particular pigmentation while caudal fin is yellowish like the body with black pigmentation at its posterior end.

Distribution. Microphis arrakisae sp. nov. is currently known from the western Indonesia islands of the Sunda Shelf, including Java, Bali and Lombok ( Figure 2 ).

Ecology

Specimens were collected in the lower course of rivers with rocky substrates comprising a mix of pebbles and sand. Microphis arrakisae sp. nov. is appears to be an amphidromous species based on its distribution across several Indonesian Islands and our previous study on freshwater pipefish otoliths ( Haÿ et al. 2023b). Microchemical analysis of the otoliths will help to confirm the life cycle of this species.

Comparison. Microphis arrakisae sp. nov. differs from M. nicoleae and M. torrentius by having more dorsal fin rays (35–38 vs 32–36) and fewer tail rings than M. torrentius (29–30 vs 30–32). While it cannot be distinguished from Microphis retzii based on morphology, it can be differentiated by body coloration: M. arrakisae sp. nov. is yellowish, whereas M. retzii is brownish. Additionally, the distinct geographical distributions the species further aid in their differentiation: M. retzii occurs in East Indonesia (Sulawesi, Ceram, Ambon and Papua) while M. arrakisae sp. nov. is found in West Indonesia (Java, Bali and Lombok). The four species exhibit similar patterns in snout and head bony ridges ( Figure 6 ). Nevertheless, a notable difference in the discontinuity of the median dorsal snout ridge is overserved, with a relatively more pronounced gap (in the length between eyes) in M. arrakisae sp. nov. and M. retzii compared to M. torrentius and M. nicoleae ( Figure 6 ).

Etymology. This new species of freshwater pipefish is named Microphis arrakisae in reference to Arrakis, the fictional planet from Frank Herbert’s novel Dune, as a tribute to this influential work of science fiction. Arrakis is predominantly covered in sand and rocks and is famously inhabited by giant sandworms known as “Shai-Hulud”. Microphis arrakisae sp. nov.. is named after this planet due to its yellowish in vivo coloration, which resembles the color of sand, and its behavior of moving between rocks, akin to a snake or a worm. This movement is reminiscent of the planet’s giant sandworms and reflects the etymology of the generic name Microphis (from Greek micro, meaning small, and ophis, meaning snake).

Figures

FIGURE 1. Bayesian tree of the cytochrome c oxydase subunit I (COI—605 pb). Numbers at each node represent posterior probabilities. In red: specimens used for morphomeristic analysis. Outgroups are represented by Hippichthys heptagonus and Hippichthys albomaculosus.

FIGURE 2. Distribution of the species. Microphis torrentius (in green), Microphis nicoleae (), Microphis retzii (in red) and Microphis arrakisae sp. nov. (in blue). Type localities: M. torrentius (■), M. nicoleae (), M. retzii (■) and M. arrakisae (■). PNG: Papua New Guinea.

FIGURE 3. Coloration in vivo of (A) Microphis retzii (male, BIF5345, Indonesia, Ceram) (Photo: N. Hubert), (B) Microphis torrentius (Female, RTNC119, New Caledonia) (Photo: N. Charpin), and (C) Microphis arrakisae sp. nov. (male, MZB.26973, tag BIF4074, Indonesia, Lombok) (Photo: N. Hubert).

FIGURE 5. Microphis arrakisae sp. nov. (A) lateral aspect of the head (B) Dorsal aspect of the head. N: naris; G: gill opening; P: Pectoral fin; O: operculum; PfB: pectoral fin base; OPR: opercular ridges; SOPR: supra-opercular ridge; SOR: supra-orbital ridge; LSR: lateral snout ridge; MDSR: median dorsal snout ridge; STR: superior trunk ridge; LTR: lateral trunk ridge; ITR: inferior trunk ridge; MVTR: median ventral trunk ridge.

FIGURE 6. Comparison of snout and head bony ridges for Microphis arrakisae sp. nov., Microphis torrentius, Microphis nicoleae and Microphis retzii. N: naris; G: gill opening; P: Pectoral fin; O: operculum; PfB: pectoral fin base; OPR: opercular ridges; SOPR: supra-opercular ridge; SOR: supra-orbital ridge; LSR: lateral snout ridge; MDSR: median dorsal snout ridge; STR: superior trunk ridge. NB: the wider snout observed in M. retzii and M arrakisae is a consequence of fixation of the specimens.