Whales - Up Close

The whalers immediately began cutting up the whale, but Klaus Barthelmess took another closer look at the whale and discovered some discrepancies. The back was gray-black and had the typical color of a fin whale, the underside of the flippers were white as was the entire belly. However, near the navel, some white pigment spots were visible on a light gray background. However, this is typical of a blue whale, which has exactly these pigment spots all over its body. The whale's entire color pattern has been described as symmetrical and uniform, but this is not the case with the fin whale because its typical identifying feature is its asymmetrical color pattern on its head, which continues down to the baleen. The right side as well as the oral cavity and baleen plates are creamy white, while the left side is uniformly gray.

As the whale was further processed, the uterus and ovaries were also routinely examined. The sensational discovery was made that the whale was pregnant, although hybrids are normally not considered capable of reproduction.

The fetus, which was approximately 20 cm in size, was recovered and was also genetically examined. In 1991, the scientific evaluation and publication of the research results of researcher R. Spilliart and his colleagues from the Marine Research Institute in Reykjavik, Iceland, for this hybrid whale appeared for the first time.

It was confirmed that this female animal, aged 7 years, was a cross between a female blue whale and a male fin whale. Analyzes of the unborn calf showed that the hybrid animal had mated with a male blue whale.

People were all the more astonished when the ovaries of this hybrid whale were examined and signs of old and scarred tissue were found in one ovary, which is called corpus albicans and could indicate a previous pregnancy. During the ovulation of an egg, the follicle from which the egg emerged fills with yellow tissue and the corpus luteum is formed, also called the corpus luteum (Latin corpus “body” and luteus “yellow”). This corpus luteum has the function of producing the hormones estrogen and progesterone, which ensure the maintenance of pregnancy. In the first 7-8 weeks of pregnancy, progesterone is produced almost exclusively by the corpus luteum, after which this task is predominantly taken over by the placenta. Only after birth does this shrink into a narrower, tough tissue and then consists exclusively of connective tissue, which appears white due to cicatricial transformation and is therefore given the name white body, Corpus albicans (Latin albicare "white").

If pregnancy does not occur, the corpus luteum in the ovary perishes more quickly. The large number of converted corpus luteums into corpus albicans then give the aging ovary its scarred appearance. This procedure can also be observed in human ovaries, because this scarred connective tissue can also be seen in the shrunken ovaries of menopausal women.

From the Handbook of Northern European Sea Fisheries, Volume XI Issue 6, from 1955, we also found an interesting reference from the earlier whaling era, because the old whalers determined the age and sexual maturity of the whales based on their ovaries, among other things. Even an external inspection of the ovaries, their size, weight and the maturing follicles indicated sexual maturity to the ancient whalers.

They also drew conclusions about the age of the whales based on the number of Corpora albicantia. At a time when whaling was active, whalers naturally had sufficient material to examine the animals they killed. Organs and intestines could be measured and weighed and so the authors of this book report that the ovaries of sexually mature whales can be up to 40 cm long, in contrast to younger, immature animals whose ovaries are only the size of a hand.

The size of an egg cell has been reported to be an average of 4.5 - 5.4 mm, while the human egg cell is only 0.11 - 0.14 mm in size and is just visible to the naked eye. The weight of the ovaries in some whales was 258 grams, while human ovaries weigh just 10-14 grams. And although this weight and length seem huge to us, they are not disproportionate in relation to the total length when compared in size to the human ovaries of a sexually mature woman, whose length is approximately 2.5 to 5 cm.

However, the information about the size and weight of the corpus luteum found in pregnant females is impressive. The blue whales were 10 centimeters tall and 1.5 to 12 kg, while the fin whale weighed 1 to 10 kg and the sperm whale 0.3 to 1.2 kg, just a single corpus luteum. The hormone from these corpus luteums, progesterone, was also used and preserved by freezing or made durable with formalin. And the yield of these effective hormones was considerable, because the same amount of hormones could be obtained from the corpus luteum of a single whale as from the corpus luteum of about a thousand pigs.

Surprisingly, there are already references to hybrid whales in the records of ancient whalers. In 1887 A.H. reported Cocks already from 6 hybrid whales along the coast of Lapland. But it wasn't until a century later that the first scientifically documented case using molecular analysis emerged. In 1970, researcher Doroshenko reported a hybrid between a blue and fin whale that was caught off Kodiak Island in the Gulf of Alaska in 1965.

There are now a total of 11 confirmed baleen whale hybrids from the wild, captured exclusively during the active whaling season. In all cases these were always crosses between blue and fin whales.

3 hybrids, one female and two males, were captured between 1983 and 1989 during the Icelandic whaling season. The most sensational case is certainly the hybrid discovered by Klaus Barthelmess, which was later described in detail by Spillart.