PYRRHOPHYTA (DINOFLAGELLATA)Ciri-ciri umum: Unicellular Memiliki
sepasang flagel yang tdk sama panjang Kosmopolitan Ada tipe
holofitik dan holozoik Ada yg parasit, saprofit
In 1753 the first modern dinoflagellates were described by Baker
and named by Muller in 1773. The term derives from the Greek word
(dinos), meaning 'whirling,' and Latin ''flagellum'', a diminutive
term for a whip or scourge.
These same dinoflagellates were first defined by Otto Btschli in
1885 as the flagellate order dinoflagellida. Botanists treated them
as a division of algae, named Pyrrhophyta ("fire algae"; Greek
pyrrhos, fire) after the bioluminscent forms, or Dinophyta.
Pigmen yang dimiliki : Chlorofil a, c,
Carotene, Xanthofil (peridinin, neoperidinin, dinoxanthin,
neodinoxanthin, diatoxanthin Ada berdinding tebal (theca) terbuat
dari selulosa, ada tdk berdinding Inti sel merupakan peralihan
antara prokariot dan eukariot (eukariot yang primitif) Jumlah
spesies +/- 2100
KlasifikasiAda 2 kelas: 1. Desmophyceae memiliki flagel yang
keluar dari ujung anterior (apical, subapical) Motil Memiliki 1
ordo : Prorocentrales
Memiliki dinding sel yang tebal, tersusun atas dua belahan
(theca) Berbentuk speris, oval, atau tetes air mata (teardrops)
Terdapat di air tawar, payau, laut Contoh genus Prorocentrum 2.
Dinophyceae flagelnya keluar dari posisi ventral. Satu flagel
terletak pada bagian sulcul, yg lainnya pada bag cingulum
Memiliki anggota lebih banyak Salah satu flagella terdpat pd
bagtransversal, yg lainnya pd bag longitudinal Memiliki 6 ordo: 1.
Dinophysiales 2. Gymnodiniales 3. Noctilucales 4. Peridiniales 5.
Gonyaulucales 6. Pyrocystales
Ordo DinophysialesBersifat motil Hidupnya soliter Memiliki
dinding sel Berbentuk pipih lateral Mempunyai tutup cingulum pada
bagian ujung anterior Epitheca pendek Menghasilkan toksin Contoh
genus Dinophysis, Ornothocercus
Ordo GymnodinialesSel motil Tidak memiliki dinding sel Berbentuk
oval Memliki girdle berbtk spiral Kosmopolitan Beberapa diantaranya
holozik Tidak menghasilkan toksin Contoh genus Gymnodinium,
Amphidinium
Ordo NoctilucalesBerukuran besar (makroplankton) sampai 2 mm
berbentuk bola Tidak berdinding sel Menghasilkan cahaya
bioluminescent Memiliki vacuola besar berperan sbg pelampung Pada
umumnya holozoik, hidup di air Laut Memiliki tentakel panjang Tidak
menghslkan toksin Contoh genus Noctiluca
Ordo PeridinialesBerdinding sel tidak dapat berubah-ubah Motil
Holozoik, sebagian besar hidup di laut Beberapa spesies memiliki
tanduk Contoh genus Peridinium
Ordo GonyaulacalesMemiliki dinding yang keras Menghasilkan
cahaya Kosmopolitan
Epitecha membentuk sebuah tanduk, hipotheca membentuk dua atau
tiga tanduk Mengalami cyclomorfosis Sebagian besar holofitik Contoh
genus Ceratium, Gonyaulax
Ordo PyrocystalesMemiliki bentuk speris, bulan sabit
Menghasilkan cahaya
Pada umumnya holofitik Dinding sel tebal tersusun atas dua lapis
(atas sporopellenin, bawah selulosa) Contoh genus Pyrocystis
REPRODUKSI Metode Utama ( normal) Pembelahan sel biasa dengan arah
transversal, longitudinal, oblique
Metode lainSeksual isogamus (lebih sering), anisogamus (jarang)
Pembentukan resting kista BIOLUMINESCEN DAN CIRCADIAN Hanya
terdapat pada spesies yang di laut Organisme yang menghslkannya
Noctiluca, Gonyaulax, Pyrocystis, Pyrodinium, Peridinium
Bioluminescence, emission of light from living organisms,
without appreciable heat. The light results from a chemical
reaction mediated by enzymes and involving specialized
phosphorus-containing molecules in the organisms. Bioluminescence
is found in species of bacteria, algae, fungi, and invertebrate
animals. Some deep-sea fish are equipped with organs that produce
luminescence to which prey is attracted.
RED TIDE DAN TOKSINKategori toksin yang dihasilkan 1. Membunuh
ikan dan sedikit invertebrata 2. Membunuh invertebrata 3. Membunuh
sedikit organisme , tapi toksin yang dihasilkan terkonsentrasi
dalam spihon atau alat pencernaan moluska Toksin yg dihslkan
Saxitoksin (neurotoksin) toksisitasnya 100 000 kali kokain
Dinoflagellates sometimes bloom in concentrations of more than a
million cells per millilitre. Some species produce neurotoxins,
which in such quantities kill fish and accumulate in filter feeders
such as shellfish, which in turn may pass them on to people who eat
them. This phenomenon is called a red tide, from the color the
bloom imparts to the water.
Organisme penyebab red tide 1. Prorocentrum 2. Gymnodinium 3.
Gonyaulax 4. Ceratium 5. Trichodesmium eritreumPengaruh toksin
Kelumpuhan (paralytic), Gangguan syaraf (neurotic), hilang ingatan
(amnetic), mencret (diarrhetic) Yg terbanyak adl PSP dan DSP
Ceratium
Peridinium
Bioluminescens
Noctiluca is not photosynthetic. It preys upon phytoplankton,
and sometimes other microscopic organisms. This cell contains
several separate food vacuoles (arrows), each containing a
different diatom colony. The genera Thalassiosira and
PERANAN
(+) Produsen primer no 2 di laut (+) Makanan ikan (-) Jika
terjadi red tide (-) Kompetitor bagi ikan dalammemperoleh
fitoplankton dan oksigen (???)
often photosynthetic protists, commonly regarded as "algae"
(Division Dinoflagellata). They are characterized by a transverse
flagellum that encircles the body (often in a groove known as the
cingulum) and a longitudinal flagellum oriented perpendicular to
the transverse flagellum. This imparts a distinctive spiral to
their swimming motion. Both flagella are inserted at the same point
in the cell wall, by convention defining the ventral surface. This
point is usually slightly depressed, and is termed the sulcus. In
heterotrophic dinoflagellates (ones that eat other organisms), this
is the point where a conical feeding structure, the peduncle, is
projected in order to consume food. Dinoflagellates possess a
unique nuclear structure at some stage of their life cycle - a
dinokaryotic nucleus (as opposed to eukaryotic or prokaryotic), in
which the chromosomes are perminently condensed. The cell wall of
many dinoflagellates is divided into plates of cellulose ("armor")
within amphiesmal vesicles, known as a theca. These plates form a
distinctive geometry/topology known as tabulation, which is the
main means for classification. Both heterotrophic (eat other
organisms) and autotrophic (photosynthetic) dinoflagellates are
known. Some are both. They form a significant part of primary
planktonic production in both oceans and lakes. Most
dinoflagellates go through moderately complex life cycles involving
several steps, both sexual and asexual, motile and non-motile. Some
species form cysts composed of sporopollenin (an organic polymer),
and preserve as fossils. Often the tabulation of the cell wall is
somehow expressed in the shape and/or ornamentation of the
cyst.