Manava Dharmashastra 5.16

5.16

pāṭhīnarohitau matsyajātiviśeṣau tayorhavyakavyaniyogena śrāddhādau bhakṣyatā'bhyanujñāyate, nānvāhnike bhojane | rājīvaliṃhatuṇḍasaśalkānāṃ sarvaśaḥ havyakavyābhyāmanyatrāpyanivṛttirbhojane | rājīvāḥ padmavarṇāḥ kaiścidiṣyante | aparaistu 'rājayo' rekhā yeṣāṃ santi | siṃhatuṇḍāḥ siṃhākṛtimukhāḥ | saśalkāḥ śakalinaḥ |

The ‘Pāṭhīna’ and the ‘Rohita’ are fit to be eaten when used as offerings to gods or Pitṛs; the ‘Rājīva’, the ‘Siṃhatuṇḍa’ and the ‘Saśalka,’ (one may eaṭ) on all occasions—(16)

Medhātithi’s commentary (manubhāṣya):
‘Pāṭhīna’ and ‘Rohita’—two particulars kinds of fish-having been mentioned as fit to be offered to Gods and to Pitṛs, the eating of these is permitted on the occasion of the performance of Śrāddha and other rites; and not in the course of ordinary daily food. As for the Rājīva, the ‘Siṃhatuṇḍa’ and the ‘Saśalka’ fish on the other hand, these are to be eaten ‘on all occasions’; i.e. they may be eaten also on occasions other than the offerings to Gods and to Pitṛs.

‘Rājīva’ some people regard this as standing for lotus-coloured fish. Others explain it as standing for those fish that are marked by lines.

‘Siṃhatuṇḍa,’—those having a lion-like face.

‘Saśalka’—is the same as the fish called ‘Shakalin.’—(16).