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CYCLOPOIDA, BILLBERG, 1820 (order)
Anterior part of the body only a little bigger than and less than twice the length of the abdomen. First antenna short, with 6-17 segments, never reaching the abdomen. Fifth leg not asymmetrical. With two brood sacks.
Micro-predators, which feeds on protists, small invertebrates and even small fish-larvae. Most copepods have mixed diets though some tend to be carnivorous while other predominantly are herbivorous.
General small-sized animals, able to avoid being predated upon by fish (Tropocyclops and Thermocyclops). (Alekseev, 2002a)

 

CYCLOPIDAE, BILLBERG, 1820 (family)

EUCYCLOPINAE, KIEFER, 1927
Last segment of fifth leg of female with 3
appendages. Caudal branches often with bristles.
Feed by seizing food when colliding with it.
Feed on bacteria, algae and zooplankton.

EUCYCLOPS, CLAUS 1893.

CFifth leg articulated with the fifth thoracic segment, angular in outline. First antenna with 6-12 segments. Outer margin of caudal branches with small distinct saw-like spines. Caudal branches usually very divergent and 4-9 times as long as wide. Lateral spine near the end of the caudal branch. The internal angle of the basipod of 4^th leg sharply produced. Both nauplii and copepodite feed on algae (diatoms and filamentous green- and bluegreen algae). Littoral.
The geographical range of E. serrulatus extends from North Africa, the Mediterranean basin, continental Europe and Russia to most of Siberia and perhaps Central Asia. In South-east Asia we know of serrulatus-like specimens close to genotype A of the type population (Northern Thailand and Southern China, Guangdong Province)(ALEKSEEV et al. 2005).

 

124 a. Rami 4-5 times longer than wide. Outer margin with dense row of small, clearly discernible saw-like small spines. 5^th leg with knife-like inner spine and two setae; outer seta equal in length to spine, middle seta about 1.3–1.5 times as long as spine. Egg sacs rather divergent, compact and pointed at the end. Size female 800-1450 μm. Littoral and tychoplanktonic, e.g. rare in plankton samples. Found abundant in the floodwater irrigating rice-fields (Schoenly 1998b). Also in brackish water. Common.
(Figures 124a¹, 124a²)
- Laguna de Bay(nauplii and female), Paoay Lake,
  La Mesa Dam,  Taal Lake, Naujan, Lake Lanao, Taal lake.
   Eucyclops serrulatus "type A", (FISHER, 1851)
            [1978a+b, 1980, 1984a, 1986a,

                    2001a+c, 2001a,  2008b, 2011a]

Note:  Some "candidate records" from the region:

Rami 4-5 times longer than wide. - Not recorded from the Philippines. Distributed in Africa and Asia. Freshwater.    Eucyclops agiloides (SARS, 1909) (?)   Rami 5 times longer than wide - Not recorded from the Philippines. Distributed in Africa and Asia. Fresh waters.     Eucyclops euacanthus (G. O. SARS, 1909)  Rami rather long. 7 times longer than wide. - Not recorded from the Philippines. Distribution: cosmopolitan, except Australia; fresh waters.        Eucyclops macruroides denticulatus (GRAETER, 1903)   Rami very long. 9 times longer than wide. - Not recorded from the Philippines. Distribution: Cosmopolitan, except Australia; fresh waters.   Eucyclops macrurus (G. O. SARS. 1863).   - Not recorded from the Philippines. Distributed in Asia: India and Java. Fresh waters.    Eucyclops permixtus KIEFER, 1928

 

 

E.  serrulatus Female from Laguna de Bay

 

(Photo Rey Donne S. Papa, 2007)

 

TROPOCYCLOPS, KIEFER, 1927
Fifth leg articulated with the fifth thoracic segment,
angular in outline. First antenna with 6-12 segments.
Outer margin of caudal branches without such spines,
and only diverging slightly, 2 1/2 times as long as
wide. The internal angle of the basipod of 4^th leg rounded producedLittoral.

125 a. One species. Egg sacs closely opposed to abdomen. Lateral spine in the middle of caudal branch. Swimming rather than creeping form, swims on its back. An especially small cyclopoid copepod. Usually size of females 680-750 μm. Herbivorous and carnivorous. Under in situ food conditions, T. p. mexicanus depended to a larger extent on algae than invertebrate prey. Daily mass-specific uptake rates for algae ranged between 10 and 24% of its body mass versus 0.7–7% for invertebrate prey. However, under enriched food availability, T. p. mexicanus is able to ingest a biomass equivalent to its body mass, with an algae (54%) and prey (40%).Body size appears to be an important factor for the relative importance of algal versus invertebrate prey for cyclopoid copepods. (Adrian and Frost, M. 1992). In ponds and littoral zone in lakes, tychoplanktonic and planktonic (form pelagica). Rare. More than 10 subspecies described in the tropics. One subspecies pantropic.
(Figures 125a¹, 125a²)
- Laguna de Bay (female), La Mesa Dam, Lake Lanao, Paoay Lake.
   Tropocyclops prasinus (FISHER, 1860)
   (syn. Eucyclops prasinus)
             [1978a+b, 1980, 1984a, 1986a, 2008b]

T.  prasinus Female from Laguna de Bay. Preserved.

PARACYCLOPS, CLAUS, 1893
Fifth leg articulated with the fifth thoracic segment,
angular in outline. First antennawith 6-12 segments.
Anterior part of body clearly flattened dorso­ventrally.
First antenna very short with 8 segments (6-11 worldwide),
reaching only to the middle of the cephalothorax.
Caudal branch long and thin, 5-6 times as long as wide,
dor­sally with transverse row of small spines. Littoral.

 

126 a. Egg sacs closely opposed to abdomen, with few
large eggs. Adaptive species, eurytherm 13.5-39^o Celsius in
 alkaline water. Size female 860-900 μm., Benthic in lakes
and rivers. Also found in rice fields. Rare.
- Laguna de Bay (littoral, adult), Los Baños, Paoay Lake.
   Paracyclops fimbriatus, (FISHER, 1853)
             [1978a+b, 1980, 1986a, 2008b]

126 b. First antenna 11 segmented. Outer branch (exopodite) of 3^rd leg with 3 spines. A predator of plant parasitic nematodes. Cosmopolite. (http://www.bar.gov.ph/database/barlib/items.asp?id=6231)(Visited April 2007)
   - Philippines
      Paracyclops affinis (SARS, 1863)
             [2001d]

 

ECTOCYCLOPS, BRADY, 1904
Fifth leg form a very short and wide plate with­out
articulation with the fifth (posterior) tho­racic segment.
First antenna with 9-10 segments. Caudal branches short
and thick with several transverse rows of small spines.
More or less littoral.
One species recorded from the Philippines.

127 a. Egg sacs closely opposed to abdomen, with few large eggs. Adaptive species, eurytherm 13.5-39^o Celsius in alkaline water. First antenna 8 segmented. Outer branch (exopodite) of 3^rd leg with 4 spines. Size female 860-900 μm. Benthic in lakes and rivers. Also found in rice fields. Rare.
- Laguna de Bay (adult), Taal Lake, Naujan, Lake Lanao, Paoay Lake.
   Ectocyclops phaleratus, (KOCK, 1838)
             [1978a+b, 1980, 1984, 1986a, 2008a]

E. phaleratus from Laguna de Bay

 

127 b. Inner dorsal spine of setae of 5^th leg much longer than the other two spines. Mainly benthic in lakes, marshes, and ephemeral waters. Often considered as a subspecies of E. phaleratus
- Not recorded in the Philippines. Distributed in
  South-East Asia (Alekseev, 2002a)
   Ectocyclops rubescens, (BRADY, 1904)
 

Note:

127 c.

MACROCYCLOPS CLAUSE, 1893.
Is not recorded from the Philippines, but Mamaril & Fernando (1978b) suggested that further sampling can reveal the presence of M. distinctus (RICHARD, 1887) from Indonesia, Sri Lanka, India or (Alekseev, 2002) the cosmopolitan species M. albidus (JURINE, 1820), M. fuscus (JURINE. 1820) or the South-East Asian species M. neuter (G. O. SARS, 1909)

 

 

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