KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 7 of 7

Some of the metrics are blocked by your
consent settings
Species range evolution of the rocky intertidal leaf oyster Isognomon nucleus (Lamarck, 1819) in the Indo-Pacific
(2026-08-01)
Mahyotsanun, Patteera
;
Shahdadi, Adnan
;
Ganmanee, Monthon
;
Chan, Benny K.K.
The small-sized leaf oyster, Isognomon nucleus, inhabits intertidal rock crevices across the tropical and subtropical Indo-Pacific (IP). This study examines the phylogeography of I. nucleus across the IP and the evolution of its distribution range using three mitochondrial markers, COX1, 12S, and 16S, and the nuclear ITS1 marker. Our phylogenetic analyses revealed a widely distributed Indo-Pacific lineage of I. nucleus from the Andaman Sea to Hawaii, and two further deeply diverged but morphologically cryptic lineages: Isognomon cf. nucleus 1, restricted to Taiwan, and Isognomon cf. nucleus 2, occurring in Taiwan and Hainan (China). Phylogeographic analyses revealed extensive gene flow within I. nucleus, spanning from the Andaman Sea in the Indian Ocean through the Philippines and Taiwan in the western Pacific to Hawaii in the Central Pacific. This high dispersal capacity is likely facilitated by west–east flowing equatorial currents and the species’ strong environmental tolerance. Higher pairwise Φst values between Hawaii and other localities indicate reduced gene flow between Hawaii and the Indo–West Pacific, consistent with Hawaii's geographic isolation. The Hawaiian endemic Isognomon californicus is closely related to I. cf. nucleus 1, suggesting that both evolved from a common ancestor and diverged as a result of limited dispersal between Taiwan and Hawaii. Demographic analyses detected clear signals of population expansion in I. nucleus coinciding with the sea level changes in the Last Glacial Maximum.
Some of the metrics are blocked by your
consent settings
Genetic differentiation and host usage of coral and fire coral-associated barnacles (Cirripedia: Pyrgomatinae and Wanellininae) across the Indian and Pacific Oceans
(2023-12-01)
Yu, Meng Chen
;
Ganmanee, Monthon
;
Tsao, Yao Feng
;
Chan, Benny K.K.
Using two molecular markers (COI and 12S) collected from seven genera and 20 species of coral associated and fire coral-associated barnacles, we examined whether genetic differentiation occurs between the Indian (total 261 sequences) and Pacific populations (195 sequences). Molecular phylogenetic analysis revealed pyrgomatinid barnacles formed two major sister-clades: the Cantellius clade and the major clade. Most of the species in the Cantellius clade did not show Indo-Pacific genetic divergence, except Cantellius sextus, which formed sister Indian and Pacific Ocean clades. Within the major clade, Darwiniella angularis, Galkinius maculosus, Nobia grandis, and Hiroa stubbingsi were composed of well-supported clades corresponding to the Indian and Pacific Oceans. The fire coral-associated barnacles Wanella milleporae have molecular clades corresponding to the populations in the Red Sea, Phuket waters, and Pacific Ocean. Species delimitation analyses and haplotype network supported the divergence of sequences in some coral barnacle species and fire coral barnacle between Indian and Pacific populations. Indo-Pacific genetic differentiation in some species appears to have resulted from Pleistocene glaciations. Life-history traits, length of larval development period, and host specificity appear can further affect the differentiation of coral barnacles across the Indian and Pacific Oceans.
Some of the metrics are blocked by your
consent settings
Integrative taxonomy, larval biology and functional morphology of the little known gall-forming coral endoparasite Petrarca (Thecostraca: Ascothoracida)
(2023-07-01)
Kolbasov, Gregory A.
;
Savchenko, Alexandra S.
;
Yu, Meng Chen
;
Tsao, Yao Feng
;
Ganmanee, Monthon
Petrarca is an ascothoracidan endoparasite in scleratinian dendrophyllid corals. Petrarca can stimulate coral growth, forming a gall chamber to house itself inside the coral skeleton. The diversity, molecular phylogeny and feeding ecology of Petrarca are understudied. This is the first study of Petrarca to be based on light and scanning electron microscopy to document the fine-scale external and functional morphology of its trophi and other structures. A combined molecular and morphological approach revealed at least four closely related species of Petrarca, P. goanna, P. morula, Petrarca nozawai sp. nov. and Petrarca rubus sp. nov. in Turbinaria and Astreopora corals in Asia. Carapace shape and fine morphology, ultrastructure of the antennular aesthetasc, morphological characteristics of the trophi and the shape and size of the penis rami are diagnostic characters. Several morphological characters, which are all probably synapomorphies, have been proposed to distinguish the genus Petrarca from other Ascothoracida. Mouthparts morphology of Petrarca are developed for cutting and chewing, rather than for piercing and sucking as in many other Ascothoracida. The external surface of the carapace of Petrarca is ornamented with densely packed secretory papillae used putatively for the chemical dissolution of the substrate necessary for the formation of the gall chamber.
Some of the metrics are blocked by your
consent settings
Biodiversity and host specificity of sponge-associated barnacles (Cirripedia: Thoracica) in Thailand
(2020-11-01)
Yu, Meng Chen
;
Chan, Benny K.K.
;
Kolbasov, Gregory A.
;
Ganmanee, Monthon
We examined the diversity and host use of sponge-associated barnacles of Thailand (Andaman Sea and the Gulf of Thailand) using a combined morphological and molecular approach. Eight barnacle species (including two new species) were collected from 12 host sponges. Host-specific barnacle species includes Acasta lappa sp. nov., which exclusively inhabits the sponge Mycale sp. Acasta milkae sp. nov. was only collected from the sponge Callyspongia cf. diffusa (Ridley, 1884). Multatria filigranus (Broch, 1916) were found in the encrusting soft sponges Monanchora unguiculata (Dendy, 1922) and Clathria sp. Pyrgospongia stellula (Rosell, 1975) inhabits the sponges Spheciospongia vagabunda (Ridley, 1884). Generalist barnacle species includes Euacsta ctenodentia (Rosell, 1972), E. porata (Nilsson-Cantell, 1921), E. zuiho (Hiro, 1936), and Acasta cyathus Darwin, 1854, which inhabit a wide range of sponges with various textures.
Some of the metrics are blocked by your
consent settings
Spatial Variation in Thermal Stress Experienced by Barnacles on Rocky Shores: The Interplay Between Geographic Variation, Tidal Cycles and Microhabitat Temperatures
(2020-07-29)
Wang, Hui Yu
;
Tsang, Ling Ming
;
Lima, Fernando P.
;
Seabra, Rui
;
Ganmanee, Monthon
Thermal stress is an important driver of species’ distribution in the intertidal zone and, with the forecasted increasing frequency of extreme high temperatures associated with climate change, is likely to play an even greater role in the future. To better understand the scales at which thermal stress impacts organisms, we used biomimetic temperature loggers (robobarnacles) to measure latitudinal variation in estimated barnacle body temperatures (Tetraclita spp.) and evaluated the influences of large, geographic, and smaller scale, microhabitat variation on temperatures experienced. Robobarnacles were deployed at nine sites along the West Pacific and South China Sea coast (five sites in Taiwan, three in Hong Kong and one in Thailand, spanning 13–25°N) from May to September 2013. Estimated body temperatures did not follow a latitudinal gradient; instead, they revealed a mosaic of hot (e.g., NE Taiwan and Thailand) and cooler sites (e.g., two sites in Hong Kong). The hot sites were characterized by frequent occurrences of “heat stress” events (estimated body temperatures ≥40°C for ≥2 h which would result in ≥50% Tetraclita entering coma). There was a correlation between hourly air temperatures and robo-temperatures, suggesting that air temperature together with solar radiation and thermal radiation re-emitted by the rocky substrate drove the observed spatial robo-temperature variation. Air temperature mediated by solar radiation and rock thermal radiation are, therefore, important contributors affecting the body temperature of sessile intertidal species in the tropical and subtropical W Pacific and South China Sea and can be a good predictor for body temperature and thermal stress of intertidal barnacles.
Some of the metrics are blocked by your
consent settings
Living in a growing host: growth pattern and dwelling formation of the scallop Pedum spondyloideum in massive Porites spp. corals
(2020-07-01)
Chan, Benny K.K.
;
Tan, James C.H.
;
Ganmanee, Monthon
Pedum spondyloideum is a byssally attached scallop in the Indo-Pacific that lives in deep fan-shaped dwellings within live scleractinian and hydrozoan corals, with the ventral edges of the scallops’ valves protruding slightly from the dwellings. Juvenile scallops have rounded, oval shells and live in shallow depressions. Complete scallop dwellings are formed by the growth of the host and allometric growth of the scallop, and by chemical and physical interactions between the scallop and its host. Scallops were extracted intact from their dwellings within massive corals in the genus Porites in Thailand (7°36′32″ N, 98°21′55″ E; in May 2019) and Malaysia (2°45′17″ N, 104°13′30″ E; in November 2019) to examine the relationship between shell height (SH) and shell width (SW). The slope of the regression of SH on SW within the first 2 years of settlement was 0.79–0.9, indicating that SW increased slightly faster than SH during this period. As the scallop grew further, the slope of the SH on SW was 1.29–1.54, indicating that SH increased faster than SW. A histological study on scallop pallial tissue, including the tentacles, and SEM observations of the dwelling walls suggested that the scallop has secretions that damage coral tissue and widen the dwelling during growth. Thus, the distinctive fan-shaped dwellings of the adult scallops are caused by a combination of allometric scallop growth and erosion of the host tissue and dwelling walls.
Some of the metrics are blocked by your
consent settings
Morphological and molecular evidence support the intertidal barnacle octomeris intermedia nilsson-cantell, 1921 (Thoracica, chthamalidae) as a valid species in indo-pacific waters
(2020-01-01)
Chan, Benny K.K.
;
Tsao, Yao Feng
;
Ganmanee, Monthon
Octomeris is a chthamalid intertidal barnacle with eight shell plates. There are currently two species of such barnacles: O. brunnea Darwin, 1854 (type locality in the Philippines), common in the Indo-Pacific region, and O. angulosa Sowerby, 1825, only recorded in South Africa. Octomeris intermedia Nilsson-Cantell, 1921, identified from the Mergui Archipelago in Myanmar, was considered to be conspecific with O. brunnea by Hiro (1939) based on samples collected in Taiwan. The morphological differences in shell and opercular plates between O. brunnea and O. intermedia are believed to be intra-specific variations due to different degrees of shell erosion. In the present study, the genetic and morphological differentiations of Octomeris in the Indo-Pacific region were examined. This study found two molecular clades (with inter-specific differences) based on the divergence in the COI genes, and the species also have distinct geographical distributions. The Octomeris brunnea clade covers samples collected from the Philippines and Taiwan waters and the other clade, which we argue is O. intermedia, is distributed in Phuket and Krabi, Thailand and Langkawi, Malaysia. Phuket and Krabi are located approximately 300 km south of the Mergui Archipelago, the type locality of O. intermedia. The morphology of samples collected from Thailand fits the type description of O. intermedia in Nilsson-Cantell (1921). Our study concludes that O. intermedia is a valid species based on morphological and molecular evidence.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results