Very clear body, lipid stores sometimes have an orange color.
Abdomen of the female contains 2 free segments, of the male – 4. P5 in males contains both the right and left leg, both four-segmented. P1 with a three segmented endopodite, the third segment carries 2 outer spines. There is no coating of small spines on the thorax or abdomen.
North Atlantic, Chukchi Sea, Bering Sea, Sea of Okhotsk, Sea of Japan. For Kosobokova & al. (2010) Eucalanus bungii bungii is an expatriate species from Pacific to the Arctic Ocean Basins, because the reproduction is not assumed in polar waters.
Oceanic, epi-bathypelagic species. Rises to the surface during cooler surface temperatures.
Females:
Large, very clear copepod with an elongate cephalothorax. Swimming appendages are separated from the mouthparts, creating a large, appendage-less area. Head is very long and triangle shaped, with lateral widenings and a sharp tip. Rostral filaments long, fused at the base. The last thoracic segment does not have extending posterior corners. The last abdominal segment is fused with the caudal rami. There is no coating of small spines on the thorax or abdomen. The left caudal ramus is slightly larger than the right, the second terminal cheata is significantly longer on the left ramus, than on the right. Endopodite of the mandibular palpus contains three long and one short chaetae. A1 longer than the body.
Males:
Cephalothorax is elongate, as in the female, but the tip of the head is much more blunt. Abdomen is 5-segmented, the last segment is fused with the caudal rami. The left caudal ramus is slightly longer than the right. A1 is shorter than the body. Mouthparts are reduced to a large extent. P5 uniramous, four-segmented, the left leg is longer than the right.
Females: 5,51-8,00 mm
Males: 4,80-6,20 mm
Filter feeder. Males, most likely, do not feed due to reduced mouth parts.
Plays a significant role in the feeding of commercially-significant fish, composing up to 60% of the diet of herring (for example, near the coast of Chukotka)
Eucalanus bungii is a copepod found in the north Pacific and surrounding waters.
E. bungii females generally range from about 5.5 to 8 millimetres (0.22 to 0.31 in) in length. Males are usually between about 4.8 and 6.2 millimetres (0.19 and 0.24 in).[1] Separation of males from females is possible in stage IV copepodites and older individuals.[2]
E. bungii is found in the north Pacific,[1] and is considered to be an expatriate to Arctic waters.[3]
There are two peaks of reproduction in E. bungii. At Station P, these peaks were observed to occur in early May and early June.[4] At Site H, off of the east coast of Hokkaido, on the other hand, reproduction occurred from April to June or July, and in August.[5] Spawning occurs at night, when the females migrate to the mixed layer.[4] Nauplii through stage II copepodites are found almost exclusively in the top 250 metres (820 ft) of depth, and they are particularly abundant above the thermocline. During the peak of their abundance, stage III through V copepodites and stage VI female copepodites are found above the thermocline. Stage VI male copepodites, on the other hand, are primarily found between 250 and 500 metres (820 and 1,640 ft) when they peak in abundance.[2]
It has been proposed that at Site H, the young spawned earlier in the year enter diapause as stage IV copepodites, and thus have an annual lifecycle, and those spawned later enter diapause as stage III copepodites, and then enter diapause again as stage V copepodites, rendering their life cycle biennial.[5] At Station P, the life cycle of E. bungii seems to be biennial, with stage III or IV copepodites entering diapause in their first summer, and then entering diapause again, usually as stage V copepodites, their second summer. Diapause occurs at depths mainly from 250 to 500 metres (820 to 1,640 ft).[4] It was found that at Site H, stage IV copepodites are generally found at this depth in diapause, whereas other copepodites in diapause were found to depths of 2,000 metres (6,600 ft).[2] At Site H, diapause occurs from August to March.[5]
Eucalanus bungii is a copepod found in the north Pacific and surrounding waters.
