Haslea nusantara (Bacillariophyceae), a new blue diatom from the Java Sea, Indonesia: morphology, biometry and molecular characterization

Abstract

Background and aims – The present study aims to describe a new species of pennate blue diatom from the genus Haslea, H. nusantara sp. nov., collected from Semak Daun Island, the Seribu Archipelago, in Indonesian marine waters.
 Methods – Assessment for species identification was conducted using light microscopy, Scanning Electron Microscopy and molecular techniques. The morphological characteristics of H. nusantara have been described, illustrated and compared to other morphologically similar blue Haslea taxa, distributed worldwide. Additionally, molecular characterization was achieved by sequencing plastidial and mitochondrial genomes.
 Key results – This new species, named Haslea nusantara, cannot be discriminated by its morphology (stria density) but it is characterized by its gene sequences (rbcL chloroplast gene and cox1 mitochondrial gene). Moreover, it differentiates from other blue Haslea species by the presence of a thin central bar, which has been previously reported in non-blue species like H. pseudostrearia. The complete mitochondrion (36,288 basepairs, bp) and plastid (120,448 bp) genomes of H. nusantara were sequenced and the gene arrangements were compared with other diatom genomes. Phylogeny analyses established using rbcL indicated that H. nusantara is included in the blue Haslea cluster and close to a blue Haslea sp. found in Canary Islands (H. silbo sp. ined.).
 Conclusions – All investigations carried out in this study show that H. nusantara is a new blue-pigmented species, which belongs to the blue Haslea clade, with an exceptional geographic distribution in the Southern Hemisphere.

Haslea silbo, A Novel Cosmopolitan Species of Blue Diatoms

“…Haslea silbo is very similar to H. ostrearia , H. karadagensis [ 19 ], H. provincialis [ 21 ], and H. nusantara [ 22 ], with respect to overall shape of the valves and the presence of blue apices. However, several characters differentiate these species.…”

“…Haslea karadagensis , H. provincialis, and H. nusantara are morphologically similar to H. ostrearia . Although these four species are easily confused based on light microscopy (LM), they show significant differences in stria densities that are only visible using scanning electron microscopy (SEM) [ 19 , 21 , 22 ]. Furthermore, they are unambiguously distinguished by molecular barcoding and phylogeny [ 19 , 21 , 22 ].…”

“…Although these four species are easily confused based on light microscopy (LM), they show significant differences in stria densities that are only visible using scanning electron microscopy (SEM) [ 19 , 21 , 22 ]. Furthermore, they are unambiguously distinguished by molecular barcoding and phylogeny [ 19 , 21 , 22 ]. Interbreeding experiments were unsuccessful at triggering auxosporulation between strains of these blue Haslea species, suggesting they belong to different taxa according to the concept of biological species [ 19 , 21 , 23 ].…”

Complex Relationships between the Blue Pigment Marennine and Marine Bacteria of the Genus Vibrio

“…H. ostrearia is a ubiquitous diatom and is of special interest in the Atlantic French coast (e.g., Marennes Bay, Bourgneuf Bay), where blooms in oyster ponds induce the greening of oyster gills that increases the market value of bivalves. Blue diatoms other than H. ostrearia have been identified in the last decade, such as Haslea karadagensis (Black Sea; [2]), Haslea provincialis (Mediterranean Sea; [3]), and more recently, Haslea nusantara (Java Sea; [4]). All these species produce blue pigments whose spectral characteristics slightly differ from marennine, and are named marennine -like pigments in the absence of more specific determination (e.g., [2]).…”

Sosialisasi Pemanfaatan Senyawa Bioaktif Dari Mikroalga Diatom Dalam Praktik Budidaya Perikanan Berkelanjutan Di Kabupaten Indramayu

“…Konsep pemanfaatan mikroalga sebagai sumber bioaktif telah menjadi pusat perhatian dalam beberapa tahun ini (Gastineau et al, 2014;Prasetiya et al, 2017;Prasetiya et al, 2019;Silkina et al, 2009;Vo et al, 2011). Namun potensi tersebut belum diketahui secara menyeluruh oleh masyarakat pesisir.…”