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2 a. Body with radial symmetry:
Craspedacusta, Freshwater medusae
With small solitary polyps and free-swimming medusae.
In freshwater. Size 20000 μm (20 mm).
Food of polyp and medusae: Asplanchna, copepods.
Although no recent records are known, it might still
be found (Terry L. Peard, Ph.D. personal communication).
Se lifecycle from (http://www.jellyfish.iup.edu/).
Craspedacusta sowerbyi, (LANKESTER)
(syn. C. sowerbii)
[Roxas 1936, in Reisinger, 1972]
2 b. Body with bilateral symmetry.......................................3
3 a. Small animals with ciliated crown or corona (wheel organ).
Body without segments. No legs present,
with or without tail like foot. Suspension feeding via coronal cilia
Food: Bacteria, algae, detritus. Planktonic or bentic:
ROTIFERA, Rotifers or Wheel animacules (phylum)..................7
3 b. Body segmented (with metamery):
ARTHROPODA, Arthropods (phylum)..................................4
4 a. Without jointed legs, (larvae) transparent, except for the black
air-sacs, of which one pair lies in thorax and one pair lies
near the end of abdomen. As fig. 4a.
(INSECTA, Insects (Class)
DIPTERA, True flies (order)
Chaoborus (syn. Corethra), Phantom midge-larvae.
Third and fourth larval instars planktonic
during night, bentic during day. With vertical
Food: zooplankton and midge-larvae (Chironomids).
In Lake Lanao Chaoborus is responsible for the major
mortality of its pry (Thermocyclops, Tropodiaptomus,
Diaphanosoma, Moina, Bosmina and Keratella). In lakes.
- Lake Lanao (C.sp = Ekstein 1)
Chaoborus manilensis, (SHINER)
[1969, Lewis 1977, 1979b]
4 b. With legs.
CRUSTACEA, Crustaceans (class)................................5
5 a. Without a shell-like covering of the body, with up to five pairs
of 2-branched swimming legs (might have a 6th rudimentary
pair of leg). Abdomen without appendages.
Size 100-2000 μm. Filtratory and/or raptorial.
Food: Algae, detritus and zooplankton.
COPEPODA, Copepods (subclass)...............................100
5 b. With a shell-like covering, which may or
may not entirely cover the body...............................6
6 a. Bivalve shell enclosing the entire body. Body not distinctly
segmented. Legs not leaf-like. Size 100-1000 μm. Planktonic
species, omnivorous, feeding on algae and detritus. (Fig. 6a:
anatomy of ostracod and sample from Laguna de Bay).
OSTRACODA, Mussel shrimps (class)CYPRIDIDAE, BAIRD 1845 (family)
Only few records. Victor (2002) gives a key to 17 genera likely to occur in Western tropical freshwaters. Following has now intention to be complete overview of the Philippine mussel shrimps:
STRANDESIA, VAVRA, 1895.
- Lake Lanao, rice fields.
Strandesia wolterecki, TRESSLER 1937.
(syn. Strandesia chondropherusa Rome, 1965)
(syn. Strandesia regularis Rome, 1962)
[1937d, 1981a,b, 2005b(key)]
- Ponds in Bocolod Chico, Mindanao.
Strandesia wierzejskii (Grochmalicki, 1915)
Other species of Strandesia found in the Philippines:
Strandesia. calapanensis Tressler, 1937
Strandesia. complexa Victor and Fernando, 1982
Strandesia. sexpunctata Klie, 1932
Strandesia. purpurascens (Brady, 1886),
(see 1981a, 2005b(key))
STENOCYPRIS, SARS 189
Endemic species in
- Laguna de Bay
Stenocypris derupta VAVRA
CYPRIA, ZENKER 1854
Adapted for benthic life, but frequently appearing in
Cypria (Cypris) spinifera, TRESSLER, 1937
EUCYPRIS Planktonic genus.
- Laguna de Bay [type locality].
Eucypris bayensis, TRESSLER, 1937
- Roadside ditch on Camaguin Island, 1932.
Eucypris orca, TRESSLER, 1937
HETEROCYPRIS, CLAUS 1892.
Dominating the invertebrate fauna together with Eucyclops serrulatus in IRRI (International Rice Research Institute, Los Baños, Luzon. In wetland rice fields it has a limiting effect of grazing on Inoculation of non-indigenous Blue Green Algae strains was establishment, but other factors were involved.
- Ricefield floodwater, IRRI.
Heterocypris lozonensis Neale,
Ostracod from Laguna de Bay
6 b. Bivalved shell (Carapace) covers the body but leaves the head free.
Legs leaf-like. Size 200-1500 μm. Filtrators, with filter setae
on the legs. Food: Algae, bacteria and detritus.
BRANCHIOPODA, Branchiopods (subclass).
CLADOCERA, Water fleas (order)
(Tagalog: Kutung tubig)...............................78
Table: Characteristics of the main groups of freshwater zooplankton. Excerpt after Brandl (2002)
Typical adult length μm
200 - 600
200 - 1500
100 - 2000
Food size μm
1 - 50
5 - 100
Mode of feeding
Suspension feeding via coronal cilia
Filtratory feeding via thoracic appendages
Filtratory and/or raptorial
Susceptibility to fish predators
Susceptibility to invertebrate predators
Moderate to high
6 c. Other groups of animal that can be found as cosmopolitans in tropical freshwater zooplankton samples are only mentioned briefly, See Fernando (2002a) for further details. The most important are:
Bryozoans or Ectoprocts: (e.g. Plumatella philippinensis KRAEPELIN, 1887, Freshwater Philippines, as floato-blasts).
http://www.nhm.ac.uk/hosted_sites/iba/bryozoa_home_page/phylactolaemata/plumatellidae/plumatella.html (visited May 2007)
Gastrotricha, Freshwater aschelminths: (e.g. Chaetonotus, in shallow ponds).
Neorhapdocoela: Turbellaria flatworms or Platyhelminthes: (e.g. Mesostomum).
Hydrocarina, Water mites, (Arthropoda): (e.g. Limnesia).
Mollusca: Bivalve Molluscs: gill lice (mussel glochidia – larvae able to attach to skin or gills of fish) (Cristaria plicata (LEACH, 1814). Very rare, in zooplankton samples in post-parasitic stage. Invasive in the Philippines. - Luzon, fishponds. Cagauan (2006)).