Marine and brackish Luticola D.G.Mann (Bacillariophyta) species from the Java Sea and South China Sea coasts with the description of three new species

By

Rybak, Mateusz
Witkowski, Andrzej
Peszek, Łukasz
Kociolek, John Patrick
Risjani, Yenny
Nguyen, Hung Duc
Zhang, Jinpeng
Yunianta, Yunianta
Nguyễn, Văn Duy
Gastineau, Romain
Duong, Thi Thuy
Rosa, Philippe
Méléder, Vona

Type

Article

Date of Publication

2021

Original Publication

PhytoKeys

Volume

183

Pages

115--142

Subjects

brackish waters , Luticola genus , marine tropical coasts , Morphology , offshore aquaculture

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers [2010]-

Identifiers

DOI: https://doi.org/10.3897/phytokeys.183.71049

 

Abstract

In this study, samples were collected from the Java Sea coasts, from the South China Sea in Hainan Island coasts and Quảng Yên region and Rú Chá mangrove near Hue in Central Vietnam. In studied samples a total of eight Luticola species have been observed. Three of the taxa studied are described herein as species new to science – Luticola orientalissp. nov., L. cribriareolatasp. nov. and L. halongianasp. nov. Under light microscopy (LM) L. orientalissp. nov. and L. cribriareolatasp. nov. are similar with rhombic-lanceolate to rhombic/ elliptic-lanceolate to elliptic valve shapes and narrowly rounded apices. Both species can be easily distinguished by stria density (higher density in L. orientalis). Under SEML. cribriareolata is characterized by cribrate areola occlusions, a character thus far observed only in three established species. The remaining species of the whole genus known thus far are characterized by hymenate areola. Similar morphology Luticola species have been observed from tropical mangrove forests from Madagascar but they all can be easily distinguished based on the lack of grooves in the central area. The third species – L. halongianasp. nov. has rhombic-elliptic to rhombic-lanceolate valves with broadly rounded to slightly protracted apices in larger specimens. This species has a relatively broad central area. Also unique among brackish-water Luticola is the small, rounded stigma positioned almost midway between the valve center and valve margin. In the habitats from which the new species are described we also identified five established Luticola taxa including, L. belawanensis, L. celebesica, L. inserata, L. seposita and L. tropica. For those species we provide detailed SEM characteristics of valve ultrastructure, as well as the range of environmental conditions and geographic distribution within the study area.