Published June 20, 2024 | Version v1
Taxonomic treatment Open

Dactylamblyops murrayi W. M. Tattersall 1939

Description

Dactylamblyops murrayi W.M. Tattersall, 1939

Figs 1–2

Dactylamblyops murrayi W.M. Tattersall, 1939: 235–237, figs 9–10 (Arabian Sea).

Dactylamblyops murrayi – Ii 1964: 289–293, figs 74–75 (detailed description, NW Pacific). — Pillai 1964: 3 (in list of Indian species); 1965: 1706–1707, fig. 53 (diagnosis, in key). — Murano 1971: 47 (in species list for Central Japan); 1981: 281–282, fig. 8 (supplementary description). — Ariani et al. 1993: table 1 (statolith structure). — Kazmi et al. 1999: 149, fig. 31 (in illustrated key to Arabian Sea species). — San Vicente & Cartes 2011: 464, table 2 (in key to species of Dactylamblyops, distribution). — Wittmann & Ariani 2019: suppl. (statolith composition, record). — Wittmann & Chevaldonné 2021: table 1 (morphology, sensory structures). — Mees & Meland 2024: Aphia-ID 226736 (accepted).

Diagnosis

Covers adults of both sexes. All features within limits of generic diagnosis. Carapace with broad triangular rostrum almost extending to distal margin of proximal segment of antennular trunk. Eyes shortly set apart, dorsoventrally compressed, cornea not divided by a ledge; ocular papilla with length ⅓–½ cornea diameter. Antennal peduncle with oblique border between median and terminal segment (Fig. 1E). Scale unsegmented, length 4–5 times maximum width; scale extending ⅕–⅓ of its length beyond antennular trunk; mesial margin setose, bare outer margin ending in a tooth. Setose terminal lobe of scale not projecting beyond disto-lateral tooth. Thoracic endopods not subchelate. Females with three pairs of oostegites. Male pleopods with endopods 2–5 and all exopods 10-segmented, no modified setae. Endopod of uropods with a single spine on inner margin below statocyst. Telson linguiform, with slightly sigmoid lateral margins, and with convex, continuously rounded terminal margin; length twice maximum width near basis. Proximal half of telson with bare lateral margins, distal half of each lateral margin with 18–32 densely set spines increasing in length distally. Terminal margin with three pairs of spines in continuous series with the lateral spines; no small spine between pair of large paramedian spines. Telson with total of 43–70 spines.

Material examined (non-type)

SOUTHERN OCEAN 1 ♀ ad. (damaged, estimated BL ≈ 15.6 mm); NE Weddell Sea, Kosminski Fracture Zone deep, ANDEEP-II station 138-6; 62°58.09ʹ S, 27°54.54ʹ W to 62°58.02ʹ S, 27°54.25ʹ W; depth 4542.5– 4541.1 m; 17 Mar. 2002; EBS supranet.

Supplementary description

EYES (Fig. 1A–D). As in diagnosis. Eyes dorsoventrally compressed by a factor of 2.4, reaching beyond median segment of antennular trunk in obliquely lateral orientation. Eyes roughly pyriform in dorsal view but lens-shaped (bolster-shaped) in lateral view (Fig. 1D). Cornea transversely positioned distally on eyestalk. It contributes to about half of eye surface. Numerous, loosely set (Fig. 1B), imperfectly developed ommatidia reach surface. Eyestalk disto-laterally with large ocular papilla anteriorly extending beyond eye (Fig. 1A). Eye papilla ends in a toroid with pore in center (Fig. 1C). Organ of Bellonci near ocular papilla. Anterior margin of cephalon with subrostral, median process reaching only to proximal third of proximal segment of antennular trunk; this process wide-angled, distally bluntly rounded.

ANTENNAE (Fig. 1E). Antennula furnished with antennular bursa as in D. benthophilus sp. nov. Female lobe of D. murrayi with minute setae; this lobe smaller than that of D. benthophilus (Fig. 5B). Distal portions of antennal scale broken; its proximal fragment with setose mesial margin and bare lateral margin.

THORAX. Dorsal portions of thorax and carapace including rostrum broken.All thoracopods broken, only sympods and oostegites remaining. Presence of 1–2 long, thick, densely barbed setae on membranous joints between at least thoracic sternites 6–7 and their respective sympods.

MARSUPIUM (Fig. 2A–C). Formed by three pairs of setose oostegites strongly increasing in size caudally. Each oostegite of present specimen proximally with brush of essentially smooth setae, some of which are distally armed with a few minute stiff bristles. Only oostegites 2–3 with series of setae along lower and caudal margins, these setae with caudally increasing incidence and size of barbs. Inner face of each oostegite with one flagellate seta showing no suture between thick handle and long slender flagellum. Only oostegite 1 with an additional smaller seta of that kind subbasally on lower margin. Only oostegite 3 with ≈ 30 slender whip setae (suture present between handle and flagellum) loosely scattered over outer face near ventral and caudal margins.

PLEON. Contributes 52% and telson 16% to estimated total length of 15.6 mm in this damaged adult female. Pleomeres 1–5 are 0.6, 0.5, 0.5, 0.5 and 0.4 times as long as pleomere 6, respectively; this value is 1.2 for telson. Female pleopods unsegmented setose rods with pseudobranchial lobe; pleopod length increases caudally.

TAIL FAN (Figs 1F, 2D). Exopod of uropods 1.5–2.0 times as long as telson, endopod 1.1–1.5 times as long as telson. Statoliths composed of fluorite. Telson linguiform with converging, slightly sigmoid lateral margins. Proximal half of each lateral margin bare, distal half with ≈32 spines, estimated based on remnants of broken spines (Fig. 1F), spines on average increasing in length distally; most spines of terminal margin broken.

Type locality and distribution

The type locality by monotypy is the Indian Ocean, northern Arabian Sea, 23°02.5ʹ N, 64°15.9ʹ E, oblique tow in 1500–0 m (W.M. Tattersall 1939; coordinates in Sewell 1935). This species was reported by Ii (1964), Murano (1981) and Wittmann & Chevaldonné (2021) from the NW Pacific, deep waters off Japan, 28° N – 36° N, 129° E – 140° E, depth 480–1200 m. All other previously published references refer to materials from these localities. The present ANDEEP record from the Southern Ocean, NE Weddell Sea, 63° S, 28° W, depth 4541–4543 m, represents strong latitudinal and bathymetric extensions of the known range. The species, so far classified as panthalassic in meso- to bathypelagic depths, has now also been recorded from bathybenthic habitats.

Notes

Published as part of Wittmann, Karl J., 2024, The Mysidae (Crustacea, Mysida) of the ANDEEP I-III expeditions to the Antarctic deep sea with the description of twelve new species, establishment of four new genera and with world-wide keys to the species of Erythropinae and Mysidellinae, pp. 1-180 in European Journal of Taxonomy 940 on pages 7-9, DOI: 10.5852/ejt.2024.940.2577, http://zenodo.org/record/12206315

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Linked records

Additional details

Biodiversity

Collection code
BL
Event date
2002-03-17
Family
Mysidae
Genus
Dactylamblyops
Kingdom
Animalia
Order
Mysida
Phylum
Arthropoda
Scientific name authorship
W. M. Tattersall
Species
murrayi
Taxon rank
species
Verbatim event date
2002-03-17
Taxonomic concept label
Dactylamblyops murrayi Tattersall, 1939 sec. Wittmann, 2024

References

  • Tattersall W. M. 1939. The Euphausiacea and Mysidacea of the John Murray Expedition to the Indian Ocean. John Murray Expedition 1933 - 1934, Scientific Reports 5: 203 - 246.
  • Ii N. 1964. Mysidae (Crustacea). In: Fauna Japonica 7: 1 - 610. Biogeographical Society of Japan, Tokyo.
  • Pillai N. K. 1964. Report on the Mysidacea in the collections of the Central Marine Fisheries Research Institute, Mandapam Camp, South India - Part I. Journal of the Marine Biological Association of India 6: 1 - 41.
  • Murano M. 1971. Mysidacean fauna in Sagami Bay and Suruga Bay. Proceedings of the Japanese Society of Systematic Zoology 7: 45 - 48. https: // doi. org / 10.19004 / pjssz. 7.0 _ 45
  • Ariani A. P., Wittmann K. J. & Franco E. 1993. A comparative study of static bodies in mysid crustaceans: evolutionary implications of crystallographic characteristics. Biological Bulletin 185: 393 - 404. https: // doi. org / 10.2307 / 1542480
  • Kazmi Q. B., Tirmizi N. M. & Mauchline J. 1999. An illustrated key to the Malacostraca (Crustacea) of the northern Arabian Sea, Pakistan. Part IV: Mysidacea. Pakistan Journal of Marine Science 8: 131 - 157.
  • San Vicente C. & Cartes J. E. 2011. Dactylamblyops corberai n. sp., a new mysid (Crustacea: Mysida) from the deep Mediterranean Sea. Scientia Marina 75: 455 - 464. https: // doi. org / 10.3989 / scimar. 2011.75 n 3455
  • Wittmann K. J. & Ariani A. P. 2019. Amazonia versus Pontocaspis: a key to understanding the mineral composition of mysid statoliths (Crustacea: Mysida). Biogeographia - The Journal of Integrative Biogeography 34: 1 - 15, Suppl.: 1 - 34. https: // doi. org / 10.21426 / B 634142438
  • Wittmann K. J. & Chevaldonne P. 2021. First report of the order Mysida (Crustacea) in Antarctic marine ice caves, with description of a new species of Pseudomma and investigations on the taxonomy, morphology and life habits of Mysidetes species. ZooKeys 1079: 145 - 227, suppl. 1. https: // doi. org / 10.3897 / zookeys. 1079.76412
  • Mees J. & Meland K. (eds) 2024. World List of Lophogastrida, Stygiomysida and Mysida. In: World Register of Marine Species. Instant Web Publishing. Available from https: // www. marinespecies. org / aphia. php? p = taxdetails & id = 931983 [accessed 19 Jan. 2024].
  • Sewell R. B. S. 1935. Introduction and list of stations. John Murray Expedition 1933 - 34, Scientific Reports 1: 1 - 41. Available from https: // ia 800207. us. archive. org / 4 / items / scientificreport 1193 john / scientificreport 1193 john. pdf [accessed 8 Sep. 2018].
  • Murano M. 1981. Mysidacea from the Central and Western Pacific V. Genera Heteroerythrops, Meierythrops, Pleurerythrops, Gibberythrops, Illigiella, Dactylamblyops, Pseudamblyops, Paramblyops, Dactylerythrops and Nakazawai (tribe Erythropini). Publications of the Seto Marine Biological Laboratory 26: 261 - 302. https: // doi. org / 10.5134 / 176038