Grimpoteuthis feitiana, Tang & Zheng & Zhang, 2025

Tang, Yan, Zheng, Xiaodong & Zhang, Junlong, 2025, Flying in the deep: the description of a new species of Grimpoteuthis (Octopoda: Cirrata: Grimpoteuthidae) from the Caroline Seamount, with ecological adaptation of dumbo octopuses, Organisms Diversity & Evolution 25 (2), pp. 269-285 : 272-276

publication ID	https://doi.org/10.1007/s13127-025-00678-x
DOI	https://doi.org/10.5281/zenodo.17633918
persistent identifier	https://treatment.plazi.org/id/03949174-FFA6-FFD6-FCA0-F9651DA1F8FC
treatment provided by	Felipe
scientific name	Grimpoteuthis feitiana
status	sp. nov.

Treatment

Grimpoteuthis feitiana sp. nov. ( Figs. 3–7 View Fig View Fig View Fig View Fig View Fig ; Tables GoogleMaps 1–2).

Species GoogleMaps LSID: urn:lsid:zoobank.org:pub:.

Material GoogleMaps examined. Holotype: MBM229046 (sex unknown, mantle length 43.6 mm, total length 212.6 mm, total weight 36.5 g), Caroline Seamount (Western Pacific Ocean) , 140.1248 E, 10.5864 N, 1240.0 m, collected by ROV ‘Faxian’, 21 August 2017 GoogleMaps .

Diagnosis

Body small-sized, bell-shaped, with moderately long, lateral fins (FL 40 mm, FW 24 mm, FLI 91.1, FWI 61.2). Cirri short (MCL 2.7 mm, MCLI 128.6), commencing between suckers 5 and 6; suckers small to moderate (MSD 2.1 mm, MSDI 4.8). Radula present, teeth homodont, seven rows. Anterior salivary gland small. Posterior salivary glands absent. Shell U-shaped; saddle shallow with slight concave outer surface, shoulders not developed; lateral wing faces otherwise flat and almost parallel, distal wings thin, expanded, lobelike, and slightly wider than saddle (SS 17.3 mm, SW 6.0 mm, SSI 95.1, SWI 88.2).

Description

Small-sized species, body semi-gelatinous, bell-shaped, antero-posteriorly elongate ( Fig. 3a–h View Fig ). Mantle about one fifth of total length (ML 44 mm, MLI 20.7), saccular, almost as long as wide, broadly rounded posteriorly. Head wider than mantle (HW 62 mm, HWI 140.9), no neck region. Pallial aperture narrow (PA 14 mm, PAI 31.8), enveloping base of funnel ( Fig. 4a View Fig ). Eyes large (EL 14–17 mm, ELI 32.3–39.9). Funnel short (FuL 10 mm, FuLI 22.7), free funnel ~ 70% of funnel length (FFuL 7 mm) ( Fig. 4a, b View Fig ). Fins moderately long (FL 40 mm, FLI 91.1), more than half as wide as long (FW 24 mm, FWI 60.0). Fins situated laterally, between the eyes and apex of the mantle, but closer to the eyes (pre-fixed specimen). Posterior margin almost straight, distal margin rounded, and anterior margin convex, tapering posteriorly towards the base. Fin bases narrow and muscular. Distal and anterior margins thin, less gelatinous. Fin cartilage and fin muscles inserting in the posterior portion of the fins, with muscle extending ∼55% fin length. Olfactory organs ovoid, small, about 0.6 mm ( Fig. 4b View Fig ). Gills compact, half-orange. Left gill damaged during capture or transportation, right gill with 4 lamellae ( Fig. 4c, d View Fig ). Branchial heart large and conspicuous. Optic lobe rounded, with single broad bundle of nerve fibers penetrating anterior half of each white body. White bodies yellowish, slightly larger than optic lobe, well separated across the dorsal midline ( Fig. 4e, f View Fig ).

Arms long, subequal and semi-gelatinous. Ventral arm shortest (AL4 154 mm, AMI4 350.0). Both dorsal arms damaged, with a small section of the left arm damaged. The right arm lost a tip and almost intact. Assuming that the widest arm corresponds to the longest one, the dorsal arm should be the longest based on the arm width. Due to prolonged preservation, thin and translucent with sector A (between dorsal arms) deepest (DWD 65 mm, DWDI 41.1), sector E (between ventral arms) shallowest (SWD 32 mm, SWDI 20.8) ( Fig. 3g, h View Fig ). The portion near arm damaged to varying degrees. Although we can infer the deepest and shallowest web, the measured depths may differ significantly from those before fixation. Web thickened at junction with ventrolateral face of each arm at level of suckers 12 (arm I and II) or 13 (arm III and IV R). Given that the only specimen was immature and damaged, we were unable to determine the presence of web nodules in this species.

Suckers uniserial, extending from the mouth opening to the arm tips ( Fig. 5a, b View Fig ). Arms with 66–69 suckers, protruding inconspicuously. No enlarged suckers, no sign of hectocotylization. Sucker moderate in size (MSD 2.1 mm, MSDI 4.8) ( Fig. 5c, d View Fig ). Proximal 7 or 8 suckers small (PSD 1.0– 1.4 mm, PSDI 2.3–3.2), with nearly rounded acetabulum imbedded in arm ( Fig. 5g View Fig ), infundibular ring thick and in-rolled towards a small aperture, petal-like. Medial sucker size increasing gradually, acetabulum projecting from arm surface, infundibular aperture large, the largest suckers about 2.1 mm, about one third of arm width ( Fig. 5h View Fig ). Distal suckers gradually decrease (DSD 0.5–1.0 mm, DSDI 1.1–2.3), located at the distal third of each arm and tightly packed, acetabulum projecting and prone to falling off, infundibular ring thick, with a light red margin and faint radial texture, infundibular aperture small ( Fig. 5e, f, i View Fig ). Cirri short, commencing as very small buds between suckers 5 and 6, extending to the tips of the arms with slight change in length along the arms ( Fig. 5a, c, d View Fig ); maximum length nearly equal to maximum sucker diameter (MCL 2.7 mm, MCLI 1.3).

Shell U-shaped, pale yellow, glossy, and transparent. Saddle shallow (SH 5.3 mm, SHI 30.6), wide (SS 17.3 mm, SSI 95.1), with slight concave outer surface and flat inner surface ( Fig. 6a, d View Fig ); shoulders blades present, not developed. Outer wing faces otherwise flat and almost parallel, distal wings thin, expanded, lobelike, and slightly wider than saddle (SS 17.3 mm, SW 6.0 mm, SSI 95.1, SWI 88.2) ( Fig. 6a, c View Fig ). Spike-like projection retracted slightly inwards relative to wings ( Fig. 6a, b View Fig ).

Digestive system with large red buccal bulb ( Fig. 7a, b, c View Fig ); two rings of glandular structures within the lips ( Fig. 7c, g View Fig ); buccal bulb with large salivary papilla, flanked by dark, thick labial palps, and a central conical odontophore; radula apparent atop the odontophore ( Fig. 7i View Fig ); anterior salivary glands small, attached to the base of the buccal mass; posterior salivary glands absent ( Fig. 7h View Fig ); oesophagus short, proximal ~ 30% narrow, remainder slightly swollen. Stomach much smaller than buccal bulb; caecum with one whorl, as large as stomach. Part of the intestine damaged, rectum short, with small bend and no clear distension. Digestive gland almost completely damaged, with only a few membranes remaining. Ink sac or anal flaps absent ( Fig. 7a View Fig ).

Upper beak ( Fig. 7d View Fig ) tall (BH 12.3 mm, BL 13.4 mm, BW 8.9 mm, H%L 91.8, H%W 138.2%); hood deep (BHL 9.7 mm, HL%L 72.4), crest convex, rostrum acutely pointed, deflected down strongly; jaw edge curved; walls almost parallel, with slightly straight edges and rounded crest. Lower beak ( Fig. 7e, f View Fig ) tall (BH 8.5 mm, BL 9.6 mm, BW 12.4 mm, H%L 88.5, H%W 68.5), hood moderate long (BHL 4.6 mm, HL%L 47.9), with rounded crest; rostrum projecting, with blunt tip; wings long (BWL 11.2 mm, WL%L 116.7); walls with convex crest. Radula present, with homodont dentition arranged in seven rows. The largest teeth about 0.15 mm in length.

The body of fresh specimen gelatinous, giving it a soft and flexible texture ( Fig. 3c–e View Fig ). Coloration orange-red, oral surfaces of arms and web, posterior mantle and fins darker; cirri and suckers warm white. Inconspicuous ring-like markings around the eye and extending from the eye to the base of the arms. In the preserved state, specimen dehydrated and wrinkled. The orange-red colors shifted more toward reddish purple; cirri and suckers light pink.

Habitat and biology

This octopod was discovered at a depth of 1240.0 m. Upon its initial discovery, it was observed lying on the seafloor, with its arms naturally bent over the surface of the seamount and its fins stretched out on each side of the mantle. As the ROV gradually approached, the octopus initiated swimming by flexing its arms to generate upward thrust, utilizing the interaction between the water current and the web. Concurrently, its fins flapped continuously in the water, but did not move quickly (see Supporting Information). To date, no studies have been published regarding the visual capabilities of cirrate octopuses. We’re not sure if this species has the same degraded vision as most other permanent residents of deep sea, but we can see from the video that the species is able to respond quickly under artificial illumination. The body length of this species was estimated to be approximately 400 mm, using laser localization underwater.

Etymology. The species epithet ‘feitiana’ is derived from ‘feitian’, a goddess known in Chinese Mogao Cave Culture for her graceful dancing in the air, resembling this dumbo octopus flying underwater.

Distribution

Known only from the Caroline Seamount, Western Pacific Ocean, 1240.0 m depth. The water temperature was about 2.31 ℃, the salinity was about 35.8 psu and PH was about 7.727.

Remarks

Based on the shell structure, fin position and size, arm length, and web form, the specimen can be readily identified as a cirrate belonging to the genus Grimpoteuthis ( Jereb et al., 2014) . In addition to the newly described species presented in this study, 17 other congeners have been documented, with 11 of them recorded in the Pacific Ocean (Table 2). The newly identified species, Grimpoteuthis feitiana sp. nov., is distinguished by its slight concave shell saddle surface (see Fig. 6a–d View Fig ), setting it apart from some Pacific congeners which have either a convex shell (as seen in G. imperator Ziegler & Sagorny, 2021 ; G. abyssicola O’Shea, 1999 ; G. innominate ( O’Shea, 1999) , G. bathynectes Voss & Pearcy, 1990 ) or a flat shell (as observed in G. hippocrepium ( Hoyle, 1904) , G. meangensis ( Hoyle, 1885)) . Furthermore, G. angularis can be differentiated from G. feitiana sp. nov. based on its radula (absent vs. present), lower sucker counts (SC 29–35 vs. 66–69), location of proximal cirrus (3–5 vs. 5–6), and shape of shell wings (expanded vs. paralell) ( Verhoeff & O’Shea, 2022). Grimpoteuthis greeni Verhoeff & O’Shea, 2022 can be distinguished from the new species by its radula (absent vs. present), the location of proximal cirrus (3–5 vs. 5–6), posterior salivary glands (present vs. absent), and more gill lamellae per demibranch (GC 7–8 vs. 4) ( Verhoeff & O’Shea, 2022). Grimpoteuthis tuftsi Voss & Pearcy, 1990 can be separated by its dentition of radula (5 rows vs. 7 rows), longer cirrus (MCL 1.5–3.5 vs. 1.3), and more gill lamellae per demibranch (GC 7–8 vs. 4) ( Voss & Pearcy, 1990). Grimpoteuthis pacifica ( Hoyle, 1885) is distinguished by its lower sucker counts (SC 52 vs. 66–69), and longer cirrus (MCLI 2 vs. 1.3) ( Hoyle, 1885).

Characteristics and architectures of the two mitogenomes

The total length of mitogenome is 16,242 bp in Grimpoteuthis feitiana sp. nov. and 16,002 bp in Grimpoteuthis sp. , respectively ( Fig. S1 View Fig ; Table S4). Each mitogenome contains 37 genes, including 13 PCGs, 22 tRNAs, 2 rRNAs and one major non-coding region ( MNR). Both mitogenomes exhibited identical, highly conserved gene order and strand distribution, i.e. 15 of the 37 genes are encoded by the plus strand and the others by the minus strand. The genes of both mitogenomes shared the same start/stop codons and exhibited similar sizes and intergenic regions. The MNRs of G. feitiana sp. and G. sp. were 1,231 and 988 bp in length, respectively, with the latter being the largest of the mitogenomes analyzed in this study ( Fig. S1 View Fig ; Table S4).

The overall AT contents of G. feitiana sp. and G. sp. were 77.42% and 77.08%, respectively, which are similar to those of octopods (ranging from 71.97% to 78.12%) ( Taite et al., 2023). The AT and GC skew values of mitogenomes were − 0.0096 and − 0.2937 for G. feitiana sp. nov.; and − 0.0029 and − 0.3053 (respectively) for Grimpoteuthis sp. (Tables S5,S6).