Hapalosoma sp. indet.

Gerdes, Klaas, Kihara, Terue Cristina, Martinez Arbizu, Pedro, Kuhn, Thomas, Schwarz-Schampera, Ulrich, Mah, Christopher L, Norenburg, Jon L, Linley, Thomas D, Shalaeva, Kate, Macpherson, Enrique, Gordon, Dennis, Stoehr, Sabine, Messing, Charles G, Bober, Simon, Guggolz, Theresa, Christodoulou, Magdalini, Gebruk, Andrey, Kremenetskaia, Antonina, Kroh, Andreas, Sanamyan, Karen, Bolstad, Kathrin, Hoffman, Leon, Gooday, Andrew J & Molodtsova, Tina, 2021, Megafauna of the German exploration licence area for seafloor massive sulphides along the Central and South East Indian Ridge (Indian Ocean), Biodiversity Data Journal 9, pp. 69955-69955 : 69955

Hapalosoma sp. indet.

Materials

Type status: Other material. Occurrence: recordedBy: BGR/ GEOMAR; individualCount: 1; lifeStage: Adult; behavior: on sediment; occurrenceStatus: present; preparations: DNA voucher and animal stored in 96% ethanol; associatedMedia: 2013-12-14 _10-56-53_Sonne_INDEX2013-2_055ROV08_Logo.jpg; associatedOccurrences: none; associatedSequences: COI; Taxon: taxonID: I13_379; scientificNameID: Sperosoma biseriatum; taxonConceptID: Hapalosoma sp. indet.; kingdom: Animalia; phylum: Echinodermata; class: Echinoidea; order: Echinothurioida; family: Echinothuriidae; genus: Hapalosoma; taxonRank: Genus; scientificNameAuthorship: Mortensen, 1903; Location: waterBody: Indian Ocean; stateProvince: Central Indian Ridge ; locality: Edmond/ Vent site 7 ; verbatimLocality: Cluster 4; maximumDepthInMeters: 3286; locationRemarks: FS Sonne Cruise INDEX2013 Leg 2; decimalLatitude: -23.8780; decimalLongitude: 69.6014; geodeticDatum: WGS84; coordinateUncertaintyInMeters: 32; Identification: identifiedBy: Andreas Kroh; identificationRemarks: Identified by morphology and DNA of collected specimen; identificationQualifier: sp. indet.; Event: eventDate: 2013-12-14; eventTime: 10:56:53 am; year: 2013; fieldNumber: INDEX2013-55ROV; Record Level: language: en; institutionCode: DZMB; collectionCode: I13_55RO_BB_1; datasetName: INDEX; basisOfRecord: Human Observation

Notes

Remarks: The echinoid seen in Fig. 166 clearly is a member of the subfamily Echinothuriinae , based on the presence of primary spines with their characteristic terminal hoofs. Identification to genus and species level is difficult in echinothurioids, specifically when based on images, since many forms are largely differentiated by details of their plate arrangement and pedicellarial morphology. In the present case, however, some information on the pedicellariae can be gained from the images. The specimen possesses very large tridentate pedicellariae with rounded blades which broaden towards the tip from a narrow base, a feature only known from species of the genus Hapalosoma (see Mortensen 1935, Anderson 2013). Four species of this genus are known ( Anderson 2013), but none of them occurring in the Indian Ocean (having been reported from the New Zealand region, Malay Archipelago and Sagami Sea). That fact, combined with the divergent colouration of the observed specimen, suggests that it might belong to a new, yet undescribed species of Hapalosoma .

Less detail can be recognszed in an individual seen in images R1915_00209 and R1915_00213, but the high similarity to the specimen in Fig. 166 suggests that this might be a second representative of this putative new species.

Figures

Figure 166. Hapalosoma sp. indet. in situ (a) and sampled specimen (b) in the surrounding area of the Edmond hydrothermal vent field in Cluster 4 of the INDEX area. Image corresponds with the data (Image attribution: BGR and GEOMAR).