Protozoa Guide review

lchthyophthirius

genus / HYMENOSTOMATIDA / ICHTHYOPHTHIRIIDAE

Description

With characters of th e fami ly (Fig. 18). dae Internal organization. (fro m Can ella and Roc ch i- Canel la, 1976) 614 CILIOPHORA , HYMENOS I •• I .• ' Figs. 20- 22 . Hyme nostom atida . Fig. 20 . Glaucoma c ha tt oni ventra l view. Ch atton & Lwoff si lver stain TOMATIA . CILIOPHORA, APOS SUBCLASS APOSTOMATIA Chatton and Lwoff, 1928 Ciliates with a polymorphic life cycle; usually epibionts of marine crustacea. Their oral structures are a rosette and usually three polykinetids (x, y , and z kineties) . Somatic cilia are monokinetids with radial transverse microtubular ribbons at triplets 3 and 4, a divergent postciliary ribbon , and a well-developed anteriorly directed kinetodesmal fibril at triplets 5-7; somatic kineties, often spiralled , number < 22 ; three orders . NOTE: The key below, based on tomite structure , is arbitrary due to the polymorphic life cycle (Figs. 1,2). At first , a generally inactive phoront occurs on the host, often encysted. It excysts during molting of, or on ingestion by, the host, becoming a trophont that feeds on exuvial fluids or tissues of its host. Later, it prepares to divide , first as a protomont , then as a tomont, that later divides many times (palintomy), often in a cyst. The new cells (protomites) mature as tomites that swim rapidly to and attach to new hosts. There they become phoronts to complete the life cycle . b 9 <9 e? 1. Kineties of tomite arched, follow rim of flattened ventral surface ... ... .... Pilisuctorida 1'. Kineties of tomite bipolar, more or less spiralled .. ... ... ..... .. ..... .. ..... .. .. ..... ........ .... . 2. Without oral apparatus and rosette ; endo- parasites of cephalopods ..... ..Astomatophorida 2' . With oral apparatus and rosette .. Apostomatida

Type species

Figures

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Raw text

With characters of th e fami ly (Fig. 18).
dae Internal organization. (fro m Can ella and Roc ch i-
Canel la, 1976)
614 CILIOPHORA , HYMENOS
I
••
I
.•
'
Figs. 20- 22 . Hyme nostom atida . Fig. 20 . Glaucoma
c ha tt oni ventra l view. Ch atton & Lwoff si lver stain
TOMATIA
.
CILIOPHORA, APOS
SUBCLASS APOSTOMATIA
Chatton and Lwoff, 1928
Ciliates with a polymorphic life cycle;
usually epibionts of marine crustacea. Their oral
structures are a rosette and usually three
polykinetids (x, y , and z kineties) . Somatic cilia
are monokinetids with radial transverse
microtubular ribbons at triplets 3 and 4, a
divergent postciliary ribbon , and a well-developed
anteriorly directed kinetodesmal fibril at triplets
5-7; somatic kineties, often spiralled , number <
22 ; three orders .
NOTE: The key below, based on tomite structure ,
is arbitrary due to the polymorphic life cycle
(Figs. 1,2). At first , a generally inactive phoront
occurs on the host, often encysted. It excysts
during molting of, or on ingestion by, the host,
becoming a trophont that feeds on exuvial fluids
or tissues of its host. Later, it prepares to divide ,
first as a protomont , then as a tomont, that later
divides many times (palintomy), often in a cyst.
The new cells (protomites) mature as tomites
that swim rapidly to and attach to new hosts. There
they become phoronts to complete the life cycle .
b
9 <9 e?
1. Kineties of tomite arched, follow rim of
flattened ventral surface ... ... .... Pilisuctorida
1'. Kineties of tomite bipolar, more or less
spiralled .. ... ... ..... .. ..... .. ..... .. .. ..... ........ .... .
2. Without oral apparatus and rosette ; endo-
parasites of cephalopods ..... ..Astomatophorida
2' . With oral apparatus and rosette .. Apostomatida