This is a very short, odd poem, and it works more by suggestion than by telling a story. The speaker calls themselves "an old fish," which fits the title "Piscean," a word linked to fish and, in astrology, to the sign Pisces. Then comes a strange image: the speaker has dinner "in a jug," as if living in a small, enclosed space, the way a fish might be kept in a jar.
The next lines drift toward talk of ice and of "who will give up all / for the oven." Ice suggests cold and stillness, while the oven suggests heat and being cooked. The poem seems to set these two fates side by side, perhaps hinting at age, sacrifice, or the pull between staying cool and being consumed.
The speaker doesn't say how they feel outright. The mood is dry, quiet, and a little darkly funny, with a sense of being confined and slightly resigned. Much of the meaning is left for the reader to fill in.