Callianira cristata Moser, 1909

Verhaegen, Gerlien, Cimoli, Emiliano & Lindsay, Dhugal, 2021, Life beneath the ice: jellyfish and ctenophores from the Ross Sea, Antarctica, with an image-based training set for machine learning, Biodiversity Data Journal 9, pp. 69374-69374 : 69374

Callianira cristata Moser, 1909

Materials

Type status: Other material. Occurrence : individualID: MCMEC2019_ Callianira _cristata_a; lifeStage: adult; associatedMedia: "https://youtu.be/ 30g 9CvYh5JE"; Taxon : scientificName: Callianira cristata; kingdom: Animalia ; phylum: Ctenophora ; class: Tentaculata ; order: Cydippida ; family: Cydippida incertae sedis; genus: Callianira ; Location: continent: Antarctica; waterBody: McMurdo Sound; maximumDepthInMeters: 1; decimalLatitude: -77.637; decimalLongitude: 166.401; Identification: identifiedBy: Dhugal Lindsay; Event: samplingProtocol: Sony Alpha 7 III camera equipped with a FE 90mm F2.8 Macro G OSS lens; eventDate: 2019-11-22; Record Level: type: Video; language: en; rightsHolder: Emiliano Cimoli Type status: Other material. Occurrence : individualID: MCMEC2019_ Callianira _cristata_b; lifeStage: adult; associatedMedia: http://morphobank.org/permalink/?P3993; Taxon : scientificName: Callianira cristata; kingdom: Animalia ; phylum: Ctenophora ; class: Tentaculata ; order: Cydippida ; family: Cydippida incertae sedis; genus: Callianira ; Location: continent: Antarctica; waterBody: McMurdo Sound; maximumDepthInMeters: 1; decimalLatitude: -77.637; decimalLongitude: 166.401; Identification: identifiedBy: Dhugal Lindsay; Event: samplingProtocol: Sony Alpha 7 III camera equipped with a FE 90mm F2.8 Macro G OSS lens; eventDate: 2019-11-20; Record Level: type: StillImage; language: en; rightsHolder: Emiliano Cimoli

Distribution

Antarctica: Ross Sea [photographed by ©Shawn Harper in Brueggeman (1998)], Gauss Station ( Moser 1909), north of Prydz Bay ( Australian Antarctic Data Centre 2019, Australian Antarctic Data Centre 2018b, Australian Antarctic Data Centre 2018c, Hosie 1991, Hosie 1999b) and west of Cape Adare ( Crossley and Hoddell 2017).

Notes

Original description after Moser (1909) (Fig. 13 A-B): length specimens 2-13 mm, body slim, slightly flattened at the stomodaeal region. Two keels at the aboral pole (i.e. “Sinnespol” in the German original version), the body gradually widening from the mouth onwards when viewed from the substomodeal plane, while appearing cylindrical and tapered towards both ends when viewed from the subtentacular plane. Lip-shaped protuberance (i.e. “Sinneskörper”) near statocyst missing. The keels are wide and short, similar to those of Callianira antarctica , but much shorter compared to those of Callianira bialata . The oval opening of the tentacle sheath is located laterally directly under the blunt tips of the keels, lower compared to C. antarctica . The comb rows lie on strong protruding meridional ridges, between which the body surface is concave. The comb rows are very long, with the substomodeal comb rows running from the height of the statocyst to one-fifth of the body length from the oral end, whereas the shorter subtentacular comb rows run from slightly deeper in the base of the wings to one-quarter of the body length from the oral end. The comb plates (i.e. “Schwimmplättchen”) lie on strongly protruding basal swellings (i.e. “Basalwülsten”); they are narrow and very long, the longest comb plates found in the aboral third of the body, from where they shorten fairly quickly in length towards the aboral pole and gradually shorten towards the oral pole. The space between the comb plates of the substomodeal comb rows is wider compared to the subtentacular ones. Two long polar plates slide between the aboral ends of the substomodeal comb rows. Mouth small and is bound by two lips lying in the stomodaeal plane. Stomach very slim and long (length ca. 4/5 body length), with short swellings. Perradial canals (i.e. “Trichtergefäß”) short, rather thick pipes. Statocyst exposed. The adradial canals (i.e. "adradialen Gefäße”) enter the meridional canals (i.e. “Meridionalgefäße ") at the same height as the infundibulum (i.e. “Trichter”). Tentacle bulbs short and wide, located very low, at the same height as the infundibulum, between the infundibulum and the body wall. The tentacle bulbs are pointed orally, split aborally into two short tips and have in their middle, both proximally and distally, each a short cone, from which the tentacle arises. Tentacle sheath (i.e. “Scheide”) short and very wide, with small oval openings near the tip of the keels. Colour not stated, likely colourless. Compared to C. antarctica , the only other Callianira species reported from the Southern Ocean (e.g. Kaufmann et al. 2011, Moser 1909, Scolardi et al. 2006, Sherlock et al. 2011), according to Moser (1909), C. cristata has narrower and extremely long comb plates and the tentacle sheath opening is closer to the tip of the keels and it has longer tentacle bulbs. Type locality: Gauss station (66.03˚S, 89.63˚E), Antarctica.

Description and comments of observed material: N = 1 in 2019 (Fig. 13 C-H). The morphological similarities observed compared to the original description of Moser (1909) were the following: body shape, keel length vs. total body length (including keel) 17%, opening of tentacle sheath located at the tip of the keels, length of substomodeal comb rows longer than subtentacular comb rows (ca. 25 vs ca. 17), comb plates laying on protruding basal swellings, long comb plates with the longest found in aboral third of the body (length of subtentacular comb plates 2.5 times the inter-comb plate distance in aboral third of body), mouth shape, slim and long pharynx (ca. 65% of body length), short and thick perradial canals, adradial canals entering meridional canals at the height of infundibulum, tentacle bulbs split aborally in two, tentacle arising from a short cone located at the middle of the tentacle bulb, polar plate length up to the second comb plate from the aboral end of the substomodeal comb rows. Dissimilarities: raised ridges present near statocyst (Fig. 13 ); many more comb plates per comb row, with ca. 25 comb plates (Fig. 12D) for substomodeal comb rows vs. 14 (Fig. 13 A) on the drawing of Moser (1909); body colourless, except for dark purple tentacle bulb and tentacles, with numerous short light purple tentilla. New reported characteristics: six ridges (Fig. 13 E), one between each substomodeal comb row and subtentacular comb row and also between adjacent substomodeal comb rows; ciliary groove running from the aboral end of the substomodeal meridional canals to the aboral pole (Fig. 13 H); in the oral third of the body, space between two substomodeal comb plates ca. equal to width of comb. It is worth noting that the validity of the genus Callianira is currently under debate and in need of a thorough revision, as the arguments to join its first three species did not meet modern standards ( Bennema and van Moorsel 2011). A recent phylogenetic study of Ctenophora, including Callianira antarctica , even suggested that Callianira should be excluded from the family Mertensiidae and should remain as incertae familae until further revision ( Townsend et al. 2020).

Figures

Figure 13. Callianira cristata. A-B. Drawing from the original description (specimen length 12 mm) (modified from Moser 1909) from Gauss Station, Antarctica: lateral view of the substomodeal plane (A) and the subtentacular plane (B); C-H. Specimen MCMEC 2019 _ Callianira _ cristata _ a observed on 22 / 11 / 2018: lateral-substomodeal views (C-D, G-H) oral view (E) and latero-aboral view (F). The contrast and brightness of images G-H were strongly modified to reveal underlying morphological structures. Abbreviations: ad-c., adradial canal; c. g., ciliary groove; m., mouth; o. t. s., opening of tentacle sheath; pe-c., perradial canal; r., ridge; st., statocyst; ss-cr., substomodeal comb row; st-cr., subtentacular comb row; t. b., tentacle bulb. C-H photos courtesy: E. Cimoli.