fish

Distinctions

dag (דג)

The plain singular. Rabbi Shlomo Pappenheim traces it to the biliteral ד-ג, fecundity and increase in number, fish being famously prolific; from the same root he takes dayag (Yeshayahu 19:8) and davag (Yirmiyahu 16:16), fisherman, and dugah (Amos 4:2), a fishing boat. Ibn Chayyuj, Ibn Janach, and Radak treat the vav in davag as root-letter. In Nechemiah 13:16 the word is written דאג though read dag: Ibn Ezra (there and in Sefer Tzachus) takes the root as triliteral ד-י-ג or ד-ו-ג with an aleph standing in for the middle letter; the Rasag commentary there reads the aleph as a derashah, that trading on Shabbos brought extra da'agah, worry, into the world.

dagah (דגה)

• Chazal (Nedarim 51b): dag is a big fish; dagah covers big and small alike. Hence Yonah's two fish, the second smaller than the first, and hence dagah for the fish of the Nile that died in Makas Dam (Shemos 7:18), where big and small perished together. On this reading the dagah the people remembered eating in Mitzrayim (Bamidbar 11:5) could be either.
• Other sources, among them Rashi (to Yonah 2:1) and Yalkut Shimoni 550: dag is a male fish, dagah a female. The first fish's belly was roomy and Yonah was too much at ease, so Hashem had it spit him out into a pregnant female whose cavity was cramped, and only then did he daven. The difficulty, which the article raises, is why only female fish would be eaten in Mitzrayim or killed in the plague. (It may suit the reading in Yoma 75a that "eating dagah" in Bamidbar 11:5 is not about food at all but about the illicit intimacy the people were free to engage in there.)
• Zohar (Beshalach 47b-48a), followed by Rabbeinu Bachaya (to Bamidbar 11:5 and in Kad HaKemach; cf. his comments to Bamidbar 22:33) and Rabbi Avraham bar Chiya HaNasi (Higayon HaNefesh): dag is a living fish, dagah a dead one. Hashem killed the fish around Yonah to make him uncomfortable enough to daven; and the Zohar further adduces the reading from Shemos 7:18, which uses dagah for the dead fish of the plague. On this reading it seems that the people in the midbar recalled eating dagah because they ate dead fish, one may not eat a live fish (see Rema, Yoreh Deah 13:1).
• Ibn Ezra (to Shemos 7:18), and see Rashi to Yirmiyahu 6:6 and Malbim to Yonah 2:2: dagah is the collective, fish as a species rather than an individual fish. This explains Shemos and Bamidbar (fish of every kind) but not the switch in Yonah.
• Rabbi Mordechai Gimpel Yaffe takes the opposite line: dagah is one particular Egyptian fish, which is why both Bamidbar 11:5 and Shemos 7:18 prefix it with the definite hei. He too leaves Yonah unexplained.

the verb (ויִדגו)

Yaakov blesses Yosef's sons v'yidgu, may they multiply like fish (Bereishis 48:16). Rav Hirsch notes that this is the only verbal use of ד-ג in all of Chumash; everywhere else the cognates are nouns. Menachem alone derives the verb from the same root as dag; Ibn Janach and Radak assign it a triliteral ד-ג-ה, though Radak seems the more open to connecting it to dag. Rabbi Yehuda Ibn Balaam lists ד-ג-ה among verbs formed from nouns; Rabbi Aharon Marcus reverses the direction, making fecundity primary and "fish" the borrowed sense, and uses this to account for Chumash never saying dag/dagim, only dagah, digas, and v'yidgu. (The article notes the counterexample itself: digei in Bereishis 9:2, apparently the construct of dag.)

the wider family

Rabbi Pappenheim also attaches two further words to ד-ג that the other commentators do not necessarily see as related. Da'agah, worry: an apprehension resting on slight grounds, like the fisherman who picks his spot on faint signs with no real proof that fish are there. Dagan, grain: the most fecund of plants, one seed begetting many, as one fish fathers many. Menachem, Ibn Janach, and Radak each give these their own triliteral roots, ד-א-ג and ד-ג-נ. Dugmah, specimen (Shabbos 10:1, Eduyos 5:6, and often in the Gemara), is said to be a loanword from the Greek deigma; but given Rabbi Pappenheim's biliteral, the column conjectures that it may derive from ד-ג too, an example being a mere sampling of a quantitatively larger pool, with the mem extraneous to the root.

As an aside, Menachem does agree that the name of the Philistine god Dagon derives from the same root as dag, the idol that represented that deity having been fish-shaped; the column treats the deity at length in the encyclopedic section of its author's God versus Gods: Judaism in the Idolatry (Mosaica Press, 2018).

the Aramaic small fish

Rashi glosses several Aramaic words as "small fish": avruma (Succah 18a; avdumah in Sefer HaAruch); munini (Sanhedrin 49a, Avodah Zarah 29a, Kesubos 60b), which also names fish brine (Rashi to Shabbos 105b, Gittin 69b) and by extension brine as such (Shabbos 110b, "munini of grasshoppers"); gildna, elsewhere a particular fish (Rashi to Sanhedrin 100b, Rabbeinu Gershom and Rashbam to Bava Basra 73b) and elsewhere small fish (Rashi to Horayos 12a, Berachos 44b, Kesubos 105b); and tzachanta (Rashi to Succah 18a, Sanhedrin 49a), which Yerushalmi Nedarim 6:3 gives as the Bavel name for the tarit. On munini: Rabbi David Golomb parses it as a diminutive mem plus the Aramaic nun, fish; Rabbi Moshe Batzri as a contraction of mei nuna, fish water. Tarit is Rashi's word for tuna (Megillah 6a, Berachos 44a), as are sultanit and the Spanish kulyis (Shabbos 39a, Chullin 66a). On the species: ichthyologists, mentioned by Dr. Moshe Raanan, identify gildna with the flathead grey mullet (Mugil cephalus) or with gilt-head bream (Sparus aurata), and modern scholars, also cited by Dr. Raanan, identify tzachanta with either sardines or anchovies. These are naturalists' proposals, not lexical rulings.

Rendering guidance

• Dag: "fish" (singular, a fish). Dagah: "fish" as well in plain narrative, but where the passage or a commentary is trading on the form, say what it means: "the fish, big and small," "a female fish," "a dead fish," "the fish" as a collective.
• Trap: English "fish" is singular and plural at once, so it will absorb dag, dagah, and dagim without a trace. In Yonah 2:1-2 that is fatal; the entire midrashic reading hangs on the one-letter change. Render "a fish" then "the fish" and carry the distinction in a note, or spell it out in the body.
• Trap: da'agah (worry) and dagah (fish) look alike and, for Rabbi Pappenheim, are related. Do not let a wordplay on the pair pass as an etymological claim in a translation; the mainstream lexicographers give them separate roots.
• V'yidgu (Bereishis 48:16) is a verb, not a noun: "may they multiply like fish," not "may they be fish."
• The Aramaic diminutives all render "small fish." Where a sugya turns on the species (kashrus signs, brine), keep the Aramaic transliterated and gloss it once, rather than committing to a modern species name in the body.

Sources

Rabbi Reuven Chaim Klein, "Fishy Words (Part 1/2)," What's in a Word?, Ohr Somayach, 18 Sivan 5781 (2021-05-29): raw text in sources/whats-in-a-word/raw/9228-fishy-words-part-12.md. Primary loci: Bereishis 9:2, 48:16; Shemos 7:18; Bamidbar 11:5, 22:33; Yeshayahu 19:8; Yirmiyahu 6:6, 16:16; Yonah 2:1-2; Amos 4:2; Nechemiah 13:16; Nedarim 51b; Yoma 75a; Succah 18a; Sanhedrin 49a, 100b; Avodah Zarah 29a; Kesubos 60b, 105b; Shabbos 39a, 105b, 110b; Gittin 69b; Horayos 12a; Berachos 44a, 44b; Megillah 6a; Chullin 66a; Bava Basra 73b; Shabbos 10:1 and Eduyos 5:6 (Mishnah); Yerushalmi Nedarim 6:3; Zohar, Beshalach 47b-48a; Yalkut Shimoni 550; Rema, Yoreh Deah 13:1; Ibn Ezra, Sefer Tzachus; Rabbeinu Bachaya, Kad HaKemach; Rabbi Avraham bar Chiya HaNasi, Higayon HaNefesh; Sefer HaAruch s.v. אברומא; Dr. Moshe Raanan on the species identifications. Rashi to Yirmiyahu 6:6, cited by the article for the collective reading, is on etzah there, a singular form denoting a plurality, "like dagah"; the word dagah itself does not occur in Yirmiyahu.