382
E. BRINTON and K. GOPALAKRISHNAN: The Distribution of Indian Ocean Euphausiids
waters south of Java. E. distinguenda is abundant at both extremes of its distribution.
As in the west, P. latifrons ranges farther southward than E. distinguenda, as far as the
coast of SW Australia. Stylocheiron insulare occurred in the Andaman Sea and south of
Java (Fig. 12).
The following more oceanic species range northward into the Bay of Bengal, evidently
by way of the Andaman Sea: Nematoscelis tenella and N. microps (Fig. 6a, b), Euphausia
pseudogibba (Fig. 8 a, b), Thysanopoda aequalis (Fig. 9 a, b), and Euphausia similis
(Fig. 11). Again, no seasonality is evident in these penetrations. The peculiar place of the
Andaman Sea in the zoography of the Bay of Bengal is further emphasized by the occurrence there of the apparently distinct species of the E. gibboides group (Fig. lOa, b) and
of Stylocheiron insulare.
On the western side of the ocean, a number of subtropical oceanic species are found
to the north of the Equator along the Somali Coast, particularly during May - September
when the northerly Somali Current is developed. These include Euphausia mutica
(Fig. 3 a), E. brevis (Fig. 4a), Nematoscelis microps and N. ten ella (Fig. 6 a, b), Stylocheiron suhmi (Fig. 7 a, b), Euphausia hemigibba (Fig. 8 a), Thysanopoda subaequalis
(Fig. 9a), and E. similis (Fig. 11). These species do not become abundant in the Somali
region and do not replace its assemblage, which is consistently characterized by E. distinguenda, E. diomediae, E. tenera, Nematoscelis gracilis, Stylocheiron affine, S. carinatum,
and Thysanopoda tricuspidata.
Records from the South African samples supplement the findings of BODEN (1954),
emphasizing the southerly occurrences in the Agulhas Current region of tropical and
subtropical species, particularly during May- September. The tropical species include:
Euphausia diomediae, to 31 0 S (Fig. 3 a)
Nematoscelis gracilis, to 27
0
S (Fig. 5 a)
Stylocheiron microphthalma, to 33
0
S (Fig. 7 a, b)
Euphausia paragibba, to 29 0 S (Fig. 8 a)
Tropical-subtropical species ranging southward include:
Euphausia brevis, to 38 0 S (Fig. 4a)
Nematoscelis microps, to 38
0
S (Fig. 6 a, b)
Nematoscelis tenella, to 32
0
S (Fig. 6 a, b)
Euphausia tenera, to 31
0
S
Thysanopoda tricuspidata, to 31 0 S
E. BRINTON and K. GOPALAKRISHNAN: The Distribution of Indian Ocean Euphausiids
waters south of Java. E. distinguenda is abundant at both extremes of its distribution.
As in the west, P. latifrons ranges farther southward than E. distinguenda, as far as the
coast of SW Australia. Stylocheiron insulare occurred in the Andaman Sea and south of
Java (Fig. 12).
The following more oceanic species range northward into the Bay of Bengal, evidently
by way of the Andaman Sea: Nematoscelis tenella and N. microps (Fig. 6a, b), Euphausia
pseudogibba (Fig. 8 a, b), Thysanopoda aequalis (Fig. 9 a, b), and Euphausia similis
(Fig. 11). Again, no seasonality is evident in these penetrations. The peculiar place of the
Andaman Sea in the zoography of the Bay of Bengal is further emphasized by the occurrence there of the apparently distinct species of the E. gibboides group (Fig. lOa, b) and
of Stylocheiron insulare.
On the western side of the ocean, a number of subtropical oceanic species are found
to the north of the Equator along the Somali Coast, particularly during May - September
when the northerly Somali Current is developed. These include Euphausia mutica
(Fig. 3 a), E. brevis (Fig. 4a), Nematoscelis microps and N. ten ella (Fig. 6 a, b), Stylocheiron suhmi (Fig. 7 a, b), Euphausia hemigibba (Fig. 8 a), Thysanopoda subaequalis
(Fig. 9a), and E. similis (Fig. 11). These species do not become abundant in the Somali
region and do not replace its assemblage, which is consistently characterized by E. distinguenda, E. diomediae, E. tenera, Nematoscelis gracilis, Stylocheiron affine, S. carinatum,
and Thysanopoda tricuspidata.
Records from the South African samples supplement the findings of BODEN (1954),
emphasizing the southerly occurrences in the Agulhas Current region of tropical and
subtropical species, particularly during May- September. The tropical species include:
Euphausia diomediae, to 31 0 S (Fig. 3 a)
Nematoscelis gracilis, to 27
0
S (Fig. 5 a)
Stylocheiron microphthalma, to 33
0
S (Fig. 7 a, b)
Euphausia paragibba, to 29 0 S (Fig. 8 a)
Tropical-subtropical species ranging southward include:
Euphausia brevis, to 38 0 S (Fig. 4a)
Nematoscelis microps, to 38
0
S (Fig. 6 a, b)
Nematoscelis tenella, to 32
0
S (Fig. 6 a, b)
Euphausia tenera, to 31
0
S
Thysanopoda tricuspidata, to 31 0 S