Calvadosia undetermined James-Clark 1863

Genus Calvadosia James-Clark, 1863 Species Calvadosia festivala n. sp. http://zoobank.org/ urn:lsid:zoobank.org:act: 328F5ADB-B298-4C10-8215-CF089862B423 Material examined. Holotype: ZCSKC (1)23, 1 specimen, Dwarka, Gujarat, India (22° 14’ 30.72 N, 68° 57’ 18.91 E), intertidal tidepool, attached to Ulva sp. (Fig. 1), 20 February 2023, formalin 4%, col. H. Baroliya. Additional material: 1 smaller specimen (Fig. 1D), Dwarka, Gujarat, India (22° 14’ 30.72 N, 68° 57’ 18.91 E), intertidal tidepool, attached to Ulva sp. (Fig. 1), 20 February 2023, ethanol 95%, col. H. Baroliya. The morphological description and measurements were based on the specimen preserved in formalin. The specimen preserved in ethanol was entirely used for molecular procedures. Diagnosis. Interradial longitudinal muscle absent in peduncle. Claustrum absent. Calyx cruciform, without anchors. Arms paired at interradii. Four U-shaped perradial notches about 1.3 times as deep as the V-shaped interradial notches. Nodular lobes of gonads curved, facing interradii. Pad-like adhesive structures on tips of arms. White nematocyst spots on subumbrella, distributed along calyx margin, at interradii and perradii, to tips of arms. White spots entering into the perradial calyx inner sinuses. White spots in the calyx margin not forming a continuous line. Slightly higher concentration of white spots at interradii in the calyx margin, perradial and interradial tips of arms, and near perradial corners of manubrium. White spots also above the nodular gonads. Dark (purplish brown) lines in the perradial side of the nodular gonads (two lines in each nodule) and in the manubrium base and corners. Etymology. The specific epithet “ festivala ” refers to the word “festival”, in tribute to the several colorful festivals celebrated in Indian culture throughout the year, therefore Calvadosia festivala n. sp. Description. The body is divided into two clearly demarcated regions, peduncle and calyx (Figs 2A, B; 3A). Peduncle short, about 1/4 of the total height, 0.28 cm tall, width 0.17 cm (Figs 2A, B; 3A). Broad, swollen adhesive circular pedal disk at the base of peduncle, width 0.26 cm (Figs 2B; 3A, C, D). Subtle and small central pore in the pedal disk (Fig. 3C, D). Peduncle without visible interradial longitudinal muscle bands, with a single chamber (based on external observations) (Fig. 2B). Calyx wider than high, cruciform, height (up to the arms tips) 0.80 cm, width 1.79 cm (Figs 2A, C–E; 3A). Calyx without anchors (rhopalioids) or primary tentacles. Manubrium width (0.44 cm) with four perradial pleated lips (Figs 2A, D; 4A, B; 5A). Many gastric filaments in the gastrovascular cavity (Fig. 5A). Gastrovascular cavity not divided by claustrum (vertical tissue composed of a double layer of gastrodermis with internal mesoglea). Eight arms (average width 0.16 cm), organized in four interradial pairs (Fig. 2A, C, D). Four U-shaped perradial notches about 1.3 times as deep as the V-shaped interradial notches (about 0.78 cm versus 0.60 cm, respectively) (Fig. 2C–E). Eight gonads not embedded in the gastrovascular cavity, but contained within evaginations from the gastrovascular cavity (Figs 2A, D; 4; 5C). Each gonad consists of several nodular lobes, irregular in shape, and arranged in a single row on the subumbrella leading out to each arm (Figs 2A, D; 4; 5C). Nodular lobes curved, facing interradii (Fig. 5C). Each arm with about 5 nodular lobes (Figs 2A, D; 4; 5C). Gonads extending from manubrium base to tips of arms (Figs 2A, D; 4; 5C). Each arm with a terminal cluster of secondary tentacles, each cluster with about 28 hollow, knobbed tentacles (Figs 2A, C–E; 3A, B; 4B, C; 5D). Outermost tentacles with a slightly swollen stem (Fig. 5D). Pad-like adhesive structures forming a glandular cushion (height 0.07 cm; width 0.20 cm) on tips of arms, on the exumbrellar side, surrounding outermost tentacles near their base (Figs 2C, E; 3A, B; 5D). Pad-like adhesive structure with an external (exumbrellar) V-shaped region, with a secondary tentacle in the middle (Fig. 5D). Four interradial longitudinal muscles at the calyx base, each divided in the pyloric region into two bands toward adradial arms, hardly discernible (Fig. 5A). Coronal muscle divided into eight segments by arms (Figs 3B; 5B). Exumbrella finely granulated with nematocyst batteries (warts) (Fig. 3B). Conspicuous white nematocyst spots on subumbrella, distributed along calyx margin, at interradii and perradii, to tips of arms (Figs 2; 3B; 4; 5A–C). White spots entering into the perradial calyx inner sinuses (Figs 2; 4). White spots in the calyx margin not forming a continuous line (Figs 2; 4). Slightly higher concentration of white spots at interradii in the calyx margin, perradial and interradial tips of arms, and near perradial corners of manubrium (Figs 2; 3B; 4; 5A–C). White spots also above the nodular gonads (Fig. 4D). General color of body translucent greenish brown, with dark (purplish brown) lines in the perradial side of the nodular gonads (two lines in each nodule) and in the manubrium base and corners (Figs 2; 4). Cnidome. Secondary tentacles with three types of nematocysts: isorhiza (Fig. 6A), length 19.44–23.54 μm (mean 21.24 μm, number of capsules measured n = 23), diameter 1.61–2.92 μm (mean 2.36 μm, n = 23); eurytele (Fig. 6B), length 13.98–15.98 μm (mean 14.93 μm, n = 9), diameter 6.73–7.87 μm (mean 7.40 μm, n = 9); and rhopaloid (Fig. 6C) (not enough information to identify them as eurytele, stenotele, or birhopaloid), length 15.08– 18.09 μm (mean 16.44 μm, n = 7), diameter 4.92–5.57 μm (mean 5.19 μm, n = 7). White nematocyst spots with one type of nematocyst: birhopaloid (Fig. 6D), length 12.74–14.34 μm (mean 13.43 μm, n = 23), diameter 9.10–10.78 μm (mean 9.99 μm, n = 23). Distribution and habitat. Dwarka, Gujarat, India (type locality). Intertidal, attached to Ulva sp. (Fig. 1). Remarks. The phylogenetic placement of the new species Calvadosia festivala is the same in ML and BA topologies for the combined dataset (Fig. 7 and Supplementary Material, Fig. 1S —see also the results of ML analyses for individual molecular markers in Supplementary Material, Figs 2S – 4S). The species is positioned in the clade that includes Calvadosia sp. Moorea, C. corbini, C. lewisi, and C. tasmaniensis with 100% support in both analyses. Calvadosia festivala resulted as a sister group of the clade that includes C. corbini, C. lewisi, and C. tasmaniensis with 93.6% and 99.9% support for ML and BA analyses, respectively. These results corroborate the hypothesis presented by Miranda et al. (2016), which retrieved a close relationship between Calvadosia sp. Moorea, C. corbini, C. lewisi (as Calvadosia sp. 4 South Africa, see Miranda et al. 2017), and C. tasmaniensis. Distance matrix (Table 3) revealed that C. festivala has the same haplotype of C. tasmaniensis for the 18S marker (however, considering a partial sequence of 826 bp for C. festivala and 594 bp for C. tasmaniensis), although for the 16S marker there is a distance of 14% between these two species, which falls in the range of interspecific variability (Holst et al. 2019). This study is the first formal description of a staurozoan species from India. However, Panikkar (1944) was the first author to report the occurrence of a stauromedusa on the Indian coast, from Krusadai Island in the Gulf of Mannar (Fig. 1), identified under the genus Lucernariospsis (Panikkar 1944), which has since been synonymized to the genus Calvadosia (Miranda et al. 2016). Panikkar described the animals with a short peduncle, single chambered, without longitudinal muscles; eight marginal arms, each of which with a cluster of knobbed tentacles; absence of marginal anchors; well-developed glandular pads on the clusters of tentacles (Panikkar 1944). All these features match our specimens, so we believe that the material observed by Panikkar (1944) could be C. festivala. Now, four species of Staurozoa are described for the Indian Ocean: C. festivala, Calvadosia capensis (Carlgren, 1938) and Lipkea stephensoni Carlgren, 1933, both from South Africa (Carlgren 1938, 1933; Miranda et al. 2017, 2018), and Haliclystus kerguelensis Vanhöffen, 1908 from Kerguelen Islands (extreme south of the Indian Ocean) (Miranda et al. 2018). Calvadosia festivala is only the fourth staurozoan species with tropical occurrence out of 51 species of Staurozoa currently considered as valid (Miranda et al. 2018, although one of them, Lucernaria janetae, occurs in the deep-sea, see Collins & Daly 2008). There are seven species in Calvadosia with pad-like adhesive structure on the tip of each arm: Calvadosia cruxmelitensis (Corbin, 1978), C. festivala, C. capensis, C. corbini, C. hawaiiensis, C. lewisi, and C. tasmaniensis. However, in C. cruxmelitensis the secondary tentacles arise directly from the pads, whereas in the other species the pads are externally separated from the secondary tentacles (Corbin 1978, Miranda et al. 2016, see figures 15A–C; 16). Additionally, Calvadosia sp. from Moorea also has pads on the tips of the arms (Miranda et al. 2016, 2017) but lacks formal description: it has been sequenced from the tissue of a young stauromedusa (Miranda et al. 2016) and it could be either an unidentified or undescribed species, as many staurozoan morphological traits vary with the stage of development (Hirano 1986). The presence of pads on the exumbrellar tips of arms, externally separated from secondary tentacles, is a potential synapomorphy of the clade [Calvadosia sp. Moorea, C. festivala, C. corbini, C. lewisi, C. tasmaniensis] (Fig. 7), which could also possibly include C. capensis and C. hawaiiensis, species with pads but without molecular data yet available (see also Miranda et al. 2016, 2017). Calvadosia capensis and C. hawaiiensis have a “closed” calyx (funnel-shaped), differently from C. festivala, which is therefore morphologically more similar to C. corbini, C. lewisi, and C. tasmaniensis, with an “open”