Tiburonia granrojo n. sp., a mesopelagic scyphomedusa from the Pacific Ocean representing the type of a new subfamily (class Scyphozoa: order Semaeostomeae: family Ulmaridae: subfamily Tiburoniinae subfam. nov.)
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- Matsumoto, G.I., Raskoff, K.A. & Lindsay, D.J. Marine Biology (2003) 143: 73. doi:10.1007/s00227-003-1047-2
Submersible observations off Japan, Hawaii, and California, USA, at depths of 645–1497 m, have revealed a previously undescribed species of large semaeostome scyphomedusa. These observations were made from 1993 to 2002. The medusa, Tiburonia granrojo n. sp. is sufficiently different from other species in the family Ulmariidae to justify the creation of a new subfamily (Tiburoniinae). This subfamily and species are distinct in overall bell morphology and color, lacking any marginal tentacles, and having four to seven short, thick oral arms that extend beyond the bell margin. The entire medusa, including the mesoglea, is a deep red. A new key to the subfamilies of the Ulmaridae and large subunit rRNA sequence information for T. granrojo are provided. That new species of this size and mass are still being discovered in the deep waters of the world suggests that deep-water species remain undescribed.1
The class Scyphozoa consists of four orders (Coronatae, Semaeostomeae, Stauromedusae, and Rhizostomeae). Only the Coronatae and Semaeostomeae are considered to be pelagic medusae, with the Stauromedusae represented by benthic species and the Rhizostomeae usually shallow water or epibenthic in nature. The pelagic scyphomedusae can be divided into two groups on the basis of their typical habitat (Larson 1986): neritic (living over the continental shelf) or oceanic (occurring beyond the continental shelf). The oceanic habitat can be further divided by depth into different zones (epipelagic, mesopelagic, bathypelagic, abyssopelagic, and hadalpelagic). Regardless of habitat, little is known about the biology and ecology of scyphomedusae. Our operations in the deep sea (at MBARI and at JAMSTEC) continue to reveal new information about the life history of scyphomedusae, but even in nearshore waters, this knowledge is incomplete. There are currently only three semaeostome genera (Deepstaria, Poralia, and Stygiomedusa) known to be mesopelagic. Each of these is monotypic and unusual in size and morphology. In this paper, we will describe a fourth mesopelagic species that represents a new species, genus, and subfamily in the order Semaeostomeae. This species was first recognized as something novel during a JAMSTEC expedition to Sagami Bay (35°00′00″N; 139°22′00″E) in 1996 (see Table 1), when an individual was photographed by Dr. T. Toda between 1196 and 1227 m. A video malfunction onboard the "Shinkai 2000" precluded both the capture of the specimen on video and the determination of the exact depth of observation. It was called the finger-foot jelly (yubiashi-kurage), but a taxonomic description was not possible with only a few images extant. A MBARI expedition to Gumdrop Seamount (37°27′11″N; 123°27′22″W) in 1998 provided more footage (stills and video), and, at this time, the species was given the common name of gumdrop jelly. The deep red pigmentation, bulky bell, varying number of oral arms, and the absence of marginal tentacles clearly distinguish it from the other subfamilies within the Ulmaridae.
Materials and methods
Tiburonia granrojo. Observations in the eastern Pacific and Hawaii using MBARI ROVs "Ventana″(V) and "Tiburon″(T) and in the western Pacific using JAMSTEC ROVs "Kaiko″(10K) and "HyperDolphin″(HD) as well as the "Shinkai 2000″(2K)
Vehicle and dive no.
Oxygen (ml l−1)
No. of oral arms
3 Aug 1993
14 Jun 1996
14 Oct 1997
21 May 1998
T088, Gumdrop Seamount
14 Jul 1998
23 Mar 1998
23 Apr 1999
23 Apr 1999
23 Feb 2000
21 Mar 2000
T119, Pioneer Seamount
23 Mar 2000
T121, Taney Seamount
27 Mar 2001
28 Mar 2001
23 Apr 2001
21 Mar 2002
26 Apr 2002
30 Apr 2002
30 Apr 2002
2 May 2002
2 May 2002
2 May 2002
18 May 2002
T425, Davidson Seamount
Materials for the present study were collected in 7.5-l "detritus samplers", designed for the gentle capture of delicate material in midwater (Youngbluth 1984). The ROV pilot positioned the vehicle so that the open cylinder of the sampler enclosed the medusa, then the sliding doors at either end were closed by hydraulic rams. Because of the large size of all but one of the observed medusae, only pieces of the medusae were collected (targeting the bell margin and the oral arms) for morphological and molecular analysis. One complete specimen was collected on 23 April 2001 and is considered the holotype specimen (deposited in the California Academy of Sciences—CASIZ 162748) with the other fragments comprising partial paratype samples (Table 1).
Tissue samples for molecular analysis were collected with the ROV "Tiburon" (23 February 2000) and either frozen at −80°C or pressed onto FTA paper (Whatman Bioscience). The 28S rRNA gene was amplified and then sequenced directly and cloned and then sequenced. In both cases, the results from multiple polymerase chain reactions or plasmid DNAs from two to five individual clones were sequenced both individually and as a pooled group.
Electronic supplementary material
Family Ulmaridae Haeckel, 1879 (Haeckel 1879)
- Tiburoniinae subfam. nov.
Diagnosis. Scyphomedusae with no marginal tentacles and four to seven thick oral arms that extend beyond the bell margin.
Type genus. Tiburonia gen. nov.
Etymology. The subfamily name comes from the ROV "Tiburon", which was the vehicle used by D. Clague during a seamount expedition in 1998 when detailed video and photographic documentation were obtained.
- Tiburonia gen. nov.
Diagnosis. Scyphomedusa with no marginal tentacles and four to seven thick oral arms that extend beyond the bell margin. This genus has a bell diameter up to 75 cm. Coloration is a deep red throughout; the oral arms are thick at the base, tapering to a blunt tip. The genus is monotypic.
Type species. granrojo sp. nov.
Etymology. The genus name comes from the ROV "Tiburon", which has been used for the majority of observations of this new genus. The genus name is feminine.
- granrojo sp. nov.
Type material. Holotype collected by the ROV "Ventana" dive 1964 on 23 April 2001; 36°42′02″N; 122°03′18″W; time of collection: 17:13:34 UMT; depth of collection: 855 m.
Examination of material
A total of 1044 bases have been sequenced from the LSU rRNA gene and have been deposited in GenBank (AY149900) and provided as an electronic supplement.
Family Ulmaridae (Larson 1986)
Gastric cavity with peripherally radiating canals (either simple or branched) that join the marginal ring canal. Oral arms either broad and curtain-like or narrow and tapering; lips usually with nematocyst-lined papillae or digitata. Gonads either inverted or everted. Tentacles either marginal or subumbrellar or absent.
With tentacles (2)
Without tentacles (5)
Gonads inverted (3)
Gonads everted (4)
Gonads separate, horseshoe shaped (Aureliinae)
Gonads contiguous and forming ring (Poraliinae)
Tentacles marginal (Ulmarinae)
Tentacles subumbrellar (Sthenoniinae)
Gastrovascular canals variably thickened, forming netlike anastomoses that peripherally decreased in size. Length of oral arms several times that of bell height (Stygiomedusinae)
Gastrovascular canals uniformly thin, forming netlike anastomoses of fairly equal size. Length of oral arms less than three times bell height (6)
five thin oral arms contained within the bell margin (Deepstariinae)
four to seven thick oral arms extending beyond the bell margin (Tiburoniinae).
This large and impressive scyphozoan has been observed in three areas in the North Pacific (Japan, Hawaii, California), suggesting a wide distribution. This novel semaeostome medusae superficially resembles Poralia sp. in coloration and in habitat, but the lack of any marginal tentacles, the much larger bell, and the varying oral arm number clearly distinguishes it from the subfamilies Poraliinae, Aureliinae, Ulmarinae, and Sthenoniinae.
Russell and Rees (1960) redefined the family Ulmaridae to include species without marginal tentacles when Stygiomedusa fabulosa was described. There is currently one species of Stygiomedusa, as S. stauchi Repelin, 1967 (Repelin 1967) has been combined with S. fabulosa (Harbison et al. 1973) and both are synonyms for Stygiomedusa gigantea Browne, 1910 (Browne 1910; Larson 1986). This genus is characterized by four oral arms, each reaching >1 m in length, and a bell morphology resembling a wide-brimmed hat. S. gigantea is viviparous, and the young have 20 or 21 marginal sense organs and ~60 marginal lappets (Russell 1959). We have never observed any gonadal development in Tiburonia granrojo, and the bell morphology lacks the wide "brim" of S. gigantea. We do know that the oral arms are much shorter than those of S. gigantea. Coloration of the two genera is similar (brownish red), as is the variable shape of the ostioles. Both genera appear to have marginal sense organs between every lappet or every other lappet, with no obvious pattern. S. gigantea has 15 to 20 radial canals that form a network of anastomoses that narrow as they approach the periphery. The radial canals of T. granrojo do not narrow, but remain uniformly thin. This, in addition to the length of the oral arms and the difference in basic bell morphology, separates these two genera.
Deepstaria enigmatica was described by Russell (1967) based on an initial collection by the submersible "Deepstar" at 723 m in the San Diego Trough. Since then, an additional species, Deepstaria reticulum Larson et al., 1988 (Larson et al. 1988), has been described. This species is reddish brown rather than the transparent white typical of D. enigmatica. D. reticulum was collected off Bermuda at 915 m depth and has been seen off Monterey, California, only once (23 November 2002 at 1400 m). It has a short, thick manubrium and eight rhopaliar lappets. D. enigmatica has been observed many times off Monterey, California, and twice off Japan (Lindsay et al. 2001). The clear color, long manubrium, five slender oral arms, and bell morphology clearly distinguish the Deepstariinae from the newly described subfamily Tiburoniinae.
The characteristics defined in this paper clearly justify the erection of a new species, genus, and subfamily within the family Ulmaridae. As explorations of the deeper regions of the world's oceans continue, we will undoubtedly continue to find new species and learn more about the ecology and natural history of these unusual and ecologically significant medusae.
We would like to thank the crews and pilots of the R.V. "Point Lobos" and the ROV "Ventana" as well as the R.V. "Western Flyer" and the ROV "Tiburon" for their expertise and patience involved with the filming and occasional collection of this unusual medusa. Thanks are also due to the captains and crews of the R.V. "Kaiyo" and the R.V. "Kairei" as well as the operations teams of the ROVs "HyperDolphin" and "Kaiko" for their dedicated efforts. This work has been supported by the Monterey Bay Aquarium Research Institute and the Japan Marine Science and Technology Center. The graphics expertise of K. Carlson with Figs. 2 and 3 has enhanced this paper, and we hope that future species descriptions will include similar illustrations when appropriate. Comments from two anonymous reviewers have improved the manuscript.