AboutRon Coleman Expertise I am an expert on cichlid fishes, particularly New World cichlids. My broader expertise includes the behavior, ecology and reproduction of fishes in general. (I am NOT an expert on Goldfish. Please do not ask me questions about why your goldfish are sick -- they are almost always sick due to the way that they are sold). Also, please do not use abbreviations, such as "my GT has a swollen
eye" because I don't know what a "GT" is. The more clearly you can explain your question, the better chance I have of understanding what it is that you seek. Thanks.
Experience I teach at the California State University, Sacramento in the Department of Biological Sciences, and I run a website, called the Cichlid Research Home Page . I also write for many popular aquarist magazines, and I am editor of Cichlid News magazine. I am a scientist and I spend my time teaching fish biology, ecology, behavior and evolution and doing research on the reproductive biology of fishes, particularly cichlids. I do research in the laboratory and in Costa Rica, Nicaragua and Mexico. My main interest is understanding the evolution of parental care in fishes. I am interested in encouraging greater public awareness, understanding and participation in science.
Organizations belong to American Cichlid Association, Pacific Coast Cichlid Association, American Society of Ichthyologists and Herpetologists, etc
Publications Cichlid News, Tropical Fish Hobbyist, Freshwater and Marine Aquarium, Science, Behavioural Ecology and Sociobiology, Copeia, Canadian Journal of Zoology, Trends in Ecology and Evolution, AUK, Environmental Biology of Fishes
Expert: Ron Coleman Date: 6/4/2008 Subject: severums
Question QUESTION: How do I tell which is the mail or female? I have a green and yellow sevrum but don't know what sex they are. Both have very long pointed dorsal and anal fins. The anal fin is very long pointed and passes the tail. Does this mean they could be male???
ANSWER: Hi Jennifer,
Actually with severums, there are no really clear differences between the sexes. Both could have long pointy fins.
-- Ron
rcoleman@cichlidresearch.com
Cichlid Research Home Page <http://cichlidresearch.com>
---------- FOLLOW-UP ----------
QUESTION: You havent answered the question HOW do I tell the difference between male and female
Answer Hi Jennifer,
The answer is that you cannot. They do not have any external markings that tell you which sex they are, what we call "dimorphic". Rather, severums are what we call "monomorphic" meaning that both sexes look the same. There are some differences between one individual and the next, but these are not related to which sex the fish is.
The only time you can really tell the sex of a severum is when they are actually spawning. At that point, the female's ovipositor (the tube which she lays the eggs with) has a different shape than the male's genital papillae (the tube which he uses to fertilize the eggs). The female tube has a blunt end while the male tube is more pointy.
-- Ron
rcoleman@cichlidresearch.com
Cichlid Research Home Page <http://cichlidresearch.com>
