-a -us -um

[Hybridfish7]

Why do we use different as suffixes for certain names? Can they be used interchangeably?
Examples: trimaculatus vs trimaculata vs trimaculatum, septemfasciata vs septemfasciatus vs septemfasciatum, nanolutea vs nanoluteus, spilurus vs spilurum, albolineata vs albolineatus, etc

 

[jjohnwm]

Latin, like many languages, has masculine and feminine nouns, complete with various descriptors to match; "la" vs "le" in French, for example. They mean the same thing, but they aren't interchangeable; it's grammatically incorrect to use "la" with a masculine noun, or "le" with a feminine noun. I remember being confused by this when the Dwarf Gourami, which was Colisa lalia (i.e. a feminine name) was moved to the already-existing genus Trichogaster (a masculine name). So it went from being Colisa lalia to Trichogaster lalius because the specific name had to match the gender of the generic name.

Just think of the Woke hysteria when it's pointed out that the fish...or maybe the words themselves?...should have the option of self-identifying with the gender of their choice. Languages like French, Spanish, Italian, etc. are going to be illegal soon...

 

[FJB]

That is exactly correct. Gender agreement is required among generic and specific epiteths, so when the genus changes…as explained above.

 

[duanes]

The genus Thorichthys is considered masculine
The genus Vieja is considered feminine (Vieja means old women in spanish),
The species melanura refers to the feminine genus Vieja,

 

[Hybridfish7]

Ah I see, so that's why it's nanolutea/septemfasciata/nigrofasciata and trimaculatus/labiatus/citrinellus

 

[Milingu]

The species melanura refers to the feminine genus Vieja,

That is a bad example because it's still Vieja melanurus. melanurus is a noun here and thereby it's not declinable.

 

[Hybridfish7]

That is a bad example because it's still Vieja melanurus. melanurus is a noun here and thereby it's not declinable.

Same concept as why sajica can't ever be sajicus or sajicum?

 

[duanes]

This comes from the CRC
Original description as Heros melanurus:
ZooBank:6FF32937-307E-441E-91EB-AB4C6F90BAF1.

• Günther, Albert C. L. G. 1862. "Catalogue of the fishes in the British Museum. Catalogue of the Acanthopterygii, Pharyngognathi and Anacanthini in the collection of the British Museum". Catalogue of the fishes in the British Museum London. 4:i-xxi + 1-534 (crc00035)

Synonyms (3):

• Heros melanopogon Steindachner, 1864, with type locality at Central America. Determiner: Regan, 1905
• Cichlasoma synspilum Hubbs, 1935, with type locality at San Pedro de Martir, a tributary of Río Usumacinta, Departamento Petén, Guatemala. Determiner: McMahan, 2011
• Cichlaurus hicklingi Fowler, 1956, with type locality at Mussell Creek, Belize River, Banking Pot, Central Farm, Belize. Determiner: Miller, 1966

The specific name melanurus is frequently treated as an adjective with the ending altered according to the gender of the generic name (e.g. Vieja melanura). However, since it was originally published without indication whether it is a noun or an adjective and could be either, it has to be treated as a noun in apposition (ICZN, 1999: Art. 31.2.2) and remains unaltered irrespective of the gender of the generic name (From Morgenstern, in press).