taxonID	type	description	language	source
DA5BB272BF35FFF02EAD6D81FD48F89A.taxon	description	The cells were solitary, transversely elongated, wider than long, dorsoventrally compressed, dorsally convex and ventrally concave, 34 – 41 μm long, and 38 – 44 μm wide, with a length to width ratio of about 0.9 (Figure 2). The epicone possessed a pointed apical protrusion (carina). The hypocone was bilobed with a deeply excavated antapex (Figure 2 A, B, D – F, H – N). The cingulum was slightly pre-median to median, descending, and displaced by about one cingular width (Figure 2 B, I, L). The sulcus continued as a short open extension onto the epicone (Figure 2 B, D, L). A short linear apical groove bisected the apex and extended to about one-third of the dorsal epicone (Figure 2 A, D, I, L, M). The nucleus was spherical and located in the left lobe of the hypocone, as seen in the ventral view (Figure 2 A, B, E, H, K, N). The cytoplasm contained numerous (16 – 26) kidney-shaped to elongated, golden-brown chloroplasts located peripherally (Figure 2 C, G). Swimming cells were able to bend along the longitudinal axis, resulting in slow movements resembling a flying butterfly (Figure 2 O – R).	en	Al-Kandari, Research Article Manal, Saburova, Maria, Polikarpov, Igor, Larsen, Jacob, Lundholm, Nina, Hussain, Sumaiah (2025): Morphological and molecular characterization of Kareniaceae (Dinophyceae, Gymnodiniales) in Kuwait’s waters. Botanica Marina (Warsaw, Poland) 68 (2): 155-173, DOI: 10.1515/bot-2024-0083, URL: https://doi.org/10.1515/bot-2024-0083
DA5BB272BF35FFF02EAD688EFA94FB35.taxon	description	The cells were solitary, oval, longer than wide, strongly dorsoventrally compressed, 30 – 33 μm long, and 24 – 27 μm wide, with a length to width ratio of about 1.2 (Figure 3). The epicone was broadly dome-shaped with slightly convex sides. The hypocone was hemispherical with a bilobed, centrally excavated antapex and a slightly protruding right lobe (Figure 3 A, B, E – I). The cingulum was slightly premedian, descending, and displaced by 1.5 – 2 cingular widths. The sulcus was narrow; its left margin opened onto the epicone as a narrow extension (Figure 3 A, B, E, F). The narrow and linear apical groove originated just above and slightly to the right of the proximal end of the cingulum and extended across the apex to about one-third down on the dorsal side of the epicone. The apex was slightly indented by the apical groove (Figure 3 A, B, E, F, H, I). The nucleus was large, oblong, transversely elongated, and located in the center of the hypocone (Figure 3 C, I, J, L). The cytoplasm contained numerous (48 – 56) plate-like, elongated, golden-brown chloroplasts with internal pyrenoids (Figure 3 C, D, K).	en	Al-Kandari, Research Article Manal, Saburova, Maria, Polikarpov, Igor, Larsen, Jacob, Lundholm, Nina, Hussain, Sumaiah (2025): Morphological and molecular characterization of Kareniaceae (Dinophyceae, Gymnodiniales) in Kuwait’s waters. Botanica Marina (Warsaw, Poland) 68 (2): 155-173, DOI: 10.1515/bot-2024-0083, URL: https://doi.org/10.1515/bot-2024-0083
DA5BB272BF35FFF12D3F6BE0FEEFF862.taxon	description	The cells were solitary, more or less oval in ventral view, 14 – 18 μm long, and 10 – 13 μm wide, with a length to width ratio of about 1.4. The cingulum was equatorial, and the epicone and hypocone were both hemispherical and nearly equal in size (Figure 4 A – D, L). The cingulum originated at the longitudinal axis of the cell, descended, and displaced about two cingular widths or 25 – 30 % of the cell length. The sulcus was sigmoid; it formed a short finger-like projection onto the epicone and continued a narrow, oblique connection between the two ends of the cingulum before fading and becoming wider posteriorly (Figure 4 A – D). A short apical groove was linear and extended across the apex and briefly down the dorsal epicone (Figure 4 B – E). In squashed cells, a pattern of knob-like structures lining the lower margin of the cingulum was discerned (Figure 4 G). No ventral pore was observed. The nucleus was located in the central part of the cell, close to the dorsal side (Figure 4 H – J). Numerous (8 – 19) irregularly shaped chloroplasts with internal pyrenoids were present (Figure 4 K). Cell division occurred at the motile stage (Figure 4 F).	en	Al-Kandari, Research Article Manal, Saburova, Maria, Polikarpov, Igor, Larsen, Jacob, Lundholm, Nina, Hussain, Sumaiah (2025): Morphological and molecular characterization of Kareniaceae (Dinophyceae, Gymnodiniales) in Kuwait’s waters. Botanica Marina (Warsaw, Poland) 68 (2): 155-173, DOI: 10.1515/bot-2024-0083, URL: https://doi.org/10.1515/bot-2024-0083
DA5BB272BF38FFFD2E836EBBFB6EF8FA.taxon	description	Molecular phylogenetic analysis using partial LSU rDNA showed that the strain from Kuwait clearly belonged to the K. selliformis clade and was genetically distinct from other Karenia species (Figure 5). Kuwait ’ s strain was most closely related to isolates from New Zealand and was 99.86 % identical (1 bp difference) to the holotype sequence of K. selliformis (U 92250). This study provides the first molecular data on K. selliformis isolated from Kuwait ’ s waters and confirms the taxonomic identity of this dinoflagellate that has caused harmful blooms. Recently, the genetic variability among the LSU rDNA and ITS sequences of K. selliformis strains originating from distant geographical areas worldwide was found to be high enough to form distinct nested subclades, suggesting the existence of two or three distinct phylotypes, depending on the molecular marker used (Iwataki et al. 2022; Mardones et al. 2020; Orlova et al. 2022). Moreover, the delineated phylotypes were distinguished phenotypically and by their temperature tolerance (Iwataki et al. 2022; Mardones et al. 2020; Orlova et al. 2022), pointing to the potential K. selliformis “ species complex ” (Mardones et al. 2020). Our morphological and molecular data support the hypothesis of phylotype separation within K. selliformis, differentiating phenotypically and by temperature preference. In the phylogeny inferred from partial LSU rDNA, the topology of the K. selliformis clade is consistent with that previously described (Mardones et al. 2020). The K. selliformis strains were grouped into distinct nested subclades representing the different phylotypes (Figure 5). The basal subclade (phylotype I) comprised strains isolated from K. selliforms bloom along the coast of the Kamchatka Peninsula in 2020. The strain from subtropical Kuwait clustered with other warm-water strains originating from New Zealand, which were closely related to the Asian strains, belonging to phylotype II, and separated from another subclade that included the Chilean strains (phylotype III). The warm-water strain from Kuwait was represented by strongly dorso-ventrally flattened cells with a distinct antapical notch consistent with the described initially K. selliformis from New Zealand waters. In contrast, strains blooming in Chile (1999), Kamchatka, Russia (2020), and Hokkaido, Japan (2021), which belong to phylotype I, exhibited cells with abundant granular to strap-shaped chloroplasts and bloomed at low temperatures <20 ° C (Iwataki et al. 2022; Orlova et al. 2022; Uribe and RuÍz 2001). The strains isolated during the K. selliformis bloom in Chile in 2018 (MN 203220 and MN 203221) were genetically distinct enough to form phylotype III. Morphologically, cells of this phylotype differed from the holotype strain by weak dorsal-ventral compression, shallower antapical excavation, and a smaller number of lateral pores in the hyposome (Mardones et al. 2020).	en	Al-Kandari, Research Article Manal, Saburova, Maria, Polikarpov, Igor, Larsen, Jacob, Lundholm, Nina, Hussain, Sumaiah (2025): Morphological and molecular characterization of Kareniaceae (Dinophyceae, Gymnodiniales) in Kuwait’s waters. Botanica Marina (Warsaw, Poland) 68 (2): 155-173, DOI: 10.1515/bot-2024-0083, URL: https://doi.org/10.1515/bot-2024-0083
DA5BB272BF38FFFA2D1D688BFC01FBEB.taxon	description	Morphologically, K. papilionacea is similar to K. brevis, and these two species can be distinguished only by minor details. The cells of K. papilionacea are wider (24 – 36 µm vs 18 – 48 µm), possess pointed rather than bulbous apical protrusions (carina), and have slightly deeper antapical excavations (Haywood et al. 2004). Given the high morphological variability observed in both species, even within the same strain (Persson et al. 2013; Stuart 2011), it is doubtful whether species discrimination based on morphological criteria alone can be considered reliable. Nevertheless, these two species are genetically distinct (Haywood et al. 2004).	en	Al-Kandari, Research Article Manal, Saburova, Maria, Polikarpov, Igor, Larsen, Jacob, Lundholm, Nina, Hussain, Sumaiah (2025): Morphological and molecular characterization of Kareniaceae (Dinophyceae, Gymnodiniales) in Kuwait’s waters. Botanica Marina (Warsaw, Poland) 68 (2): 155-173, DOI: 10.1515/bot-2024-0083, URL: https://doi.org/10.1515/bot-2024-0083
DA5BB272BF38FFFA2D1D688BFC01FBEB.taxon	description	In the phylogenetic tree based on partial LSU rDNA sequences, the strains from Kuwait were grouped together within the monophyletic clade of K. papilionacae among strains isolated from New Zealand (the type locality) and Japan with strong statistical support (Figure 5). The sequences obtained from Kuwait ’ s strains were identical, sharing 99.7 % similarity (2 bp differences) to that of the type strain of K. papilionacea (U 92252), and were clearly genetically distinct from the K. brevis clade. Therefore, our results provide the first unambiguous molecular identification of K. papilionacea from Kuwait ’ s coastal waters and resolve the previous regional taxonomic uncertainty for this species. This implies that earlier records of K. brevis - like species in Kuwait ’ s waters need to be reconsidered and attributed to K. papilionacea. Furthermore, the genetic similarity among the strains isolated seven years apart (first in 2014 and then in 2021) and from different sampling sites (Kuwait Bay and semi-enclosed marina, Figure 1 C; Table 1) suggests the persistent presence of the same population of this species throughout the study area. Similar to K. selliforms, recent phylogenetic analyses based on both LSU and ITS have revealed genetic divergence among the K. papilionacea strains, resulting in the distinction of at least two phylotypes within this species (Kim et al. 2023; Yamaguchi et al. 2016). No morphological differences were observed between phylotypes, while different physiological growth traits were assumed to distinguish them (Yamaguchi et al. 2016). In our LSU-based phylogeny, the topology of the K. papilionacea clade was almost the same as previously reported by Yamaguchi et al. (2016) and Kim et al. (2023) and consisted of three distinct, well-supported subclades (Figure 5). All of Kuwait ’ s strains were placed in a large, diverse, and strongly supported clade (89 / 0.99) among strains from Australia, New Zealand, Japan, China, and Korea, corresponding to the original phylotype (as per Yamaguchi et al. 2016). The second distinct subclade, with high nodal support (85 / 0.99), solely comprised K. papilionacea strains restricted to the western Japanese coast (Yamaguchi et al. 2016), representing phylotype I. Two strains originating from the French Atlantic and north-western Mediterranean Sea, Spain, were genetically divergent from those of the original phylotype and phylotype I, clustering separately into a well-supported subclade (86 / 0.99).	en	Al-Kandari, Research Article Manal, Saburova, Maria, Polikarpov, Igor, Larsen, Jacob, Lundholm, Nina, Hussain, Sumaiah (2025): Morphological and molecular characterization of Kareniaceae (Dinophyceae, Gymnodiniales) in Kuwait’s waters. Botanica Marina (Warsaw, Poland) 68 (2): 155-173, DOI: 10.1515/bot-2024-0083, URL: https://doi.org/10.1515/bot-2024-0083
DA5BB272BF3FFFFB2D3F6B85FB24FC0B.taxon	description	The phylogenetic tree inferred from the LSU rDNA sequences in the present study also showed a high genetic similarity between the sequences obtained from Kuwait and the type material of Karl. ballantinum from Tasmania (Figure 5). Kuwait ’ s strains shared 98.19 – 99.27 % similarity (5 bp differences) with the holotype strain EF 469232. Through combined evidence from molecular phylogeny and morphology, this study reports the identification of K. ballantinum in Kuwait ’ s waters, marking the first record of this species in the entire Gulf.	en	Al-Kandari, Research Article Manal, Saburova, Maria, Polikarpov, Igor, Larsen, Jacob, Lundholm, Nina, Hussain, Sumaiah (2025): Morphological and molecular characterization of Kareniaceae (Dinophyceae, Gymnodiniales) in Kuwait’s waters. Botanica Marina (Warsaw, Poland) 68 (2): 155-173, DOI: 10.1515/bot-2024-0083, URL: https://doi.org/10.1515/bot-2024-0083
