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Pictures from a microscopic world

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10.08.2006

During a survey in South African and Namibian waters last year, fish eggs and fish larvae from a number of species were collected by scientists from the Institute of Marine Research (IMR) in cooperation with scientists from the region.

Larvae of monkfish/anglerfish (Lophius vomerinus) ca. 5mm. The dorsal, pectoral and pelvic fins are very elongate at this stage.

The planktonic eggs and larvae are small and are best viewed through a microscope and therefore unknown to most people. Many of the species or close relatives are found also in more northern waters, and species such as monkfish, pearlside, horse mackerel, blackbelly rosefish (jacopever), gurnard and John dory are well known.

During our surveys in Namibia and South Africa we manage to identify most eggs and larvae. Since this is a relatively cold upwelling area, few species dominates and these are well documented in the literature even in the egg and larval stages. The challenge increases when we sometimes cross the front between the cold Benguela water and the warmer water of the Angola current. The number of species increase and many of the species are not well documented on the egg and larval stage.

In cooperation with local institutions, IMR has conducted several hake surveys in the region. The main goal has been to assess the stock size, but recently the focus has been directed towards life history studies and particularly to investigate whether the stocks of hake are shared between Namibia and South Africa. During last year's survey, we tried to map the spawning areas and the eggs and larval drift routes.

Yvonne Robberstad | Source: alphagalileo
Further information: www.imr.no/english/news/news_2006/a_microscopic_world

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