A montage of attractive Trimma gobies from the new, all-encompassing key to the genus from Richard Winterbottom and the Journal of the Ocean Science Foundation. See the key to species below.

Some readers with good memories may get a sense of déjà vu, with good reason. Back in 2017, David W. Greenfield and Richard Winterbottom published an amazing, free, open-access identification key to 107 species of Eviota dwarfgobies. In late 2019, Winterbottom brought tiny gobies back into the spotlight with a similar (also free) illustrated key to 105 validly described pygmygobies of the genus Trimma.

Trimma habrum has an unusual translucent dorsum. Photographed at Sulawesi, Indonesia, by Mark V. Erdmann

In addition to being a wealth of species imagery, Winterbottom’s work raises interesting observations for the would-be Trimma goby keeper, or anyone interested in breeding them. Of particular note is the incredibly short lifespan given for two Trimma species from Palau. Trimma benjamini (#3 in composite image above) has a maximum reported lifespan of only 140 days; nearly 1/3rd  of its lifespan is devoted to the larval period. The even faster-growing Trimma nasa has a calculated maximum life span only 87 days!

Trimma caudomaculatum, photographed at Hithadhoo, Maldives, by Mark V. Erdmann

Aquarists should not be surprised if their Trimma goby, with its short lifespan, has just a fleeting time in their aquarium. This also means that breeders would be wise to produce these fish on a larger scale, given the short generation time and the resultant higher concern of inbreeding in a captive population. Also of interest, Winterbottom’s reporting notes that 29 of 31 species of Trimma examined are proven or likely bi-directional hermaphrodites, which means in those species, putting two young individuals together should produce a male/female pair. However, at least two species of Trimma are known to be gonochorists (having fixed sex).

Trimma lanata, seen here at Milne Bay, PNG, has a beautiful blue face. Image by Mark V. Erdmann

It’s clear that a document of this scope takes tremendous time, tedious review, and an incredible spirit of collaboration. Once again, we applaud this effort, and we’re especially lucky to have it published in open-access form.

The beautiful Pajama Pygmy Goby, Trimma pajama, was only described in 2014. Seen here at Penemu Lagoon, Raja Ampat, Indonesia, photographed by Mark V. Erdmann.

Don’t delay! Add this to your digital library for FREE today! Download Winterbottom’s Guide to Trimma goby species here: http://oceansciencefoundation.org/josf34a.html

References:

Winterbottom, R. (2019) An illustrated key to the described valid species of Trimma (Teleostei: Gobiidae). Journal of the Ocean Science Foundation, 34, 1-61.

(locally mirrored PDF copy: if the above link doesn’t work, download here)

The genus Trimma on Fishbase

Appendices:

Trimma Species IDs and Photo Credits for Opening Compiled Image:

1. T. fangi, Waga Waga, Milne Bay, PNG (Mark V. Erdmann)
2. T. grammistes, Osezaki, Shizuoka, Japan, (Vin/ Izuzuki [CC -by-2.1-jp] www.izuzuki.com/Zukan/Fish/haze/ichimonjiHZ.html)
3. T. benjamini, Sumbawa, Teluk Saleh (Mark V. Erdmann)
4. T. striatum, Laamu, Maldives (Mark V. Erdmann)
5. T. trioculatum, fresh,16.5 mm SL female paratype, ROM 95249, Cenderawasih Bay (Mark V. Erdmann)
6. T. cana, Widi, Halmahera, Maluku, Indonesia (Mark V. Erdmann)
7. T. maiandros, Grotto, Saipan, Northern Mariana Islands (Hiro Kimura).
8. T. chledophilum, Sideia, Milne Bay, Papua New Guinea (Mark V. Erdmann)
9.  T. avidori, Sudan (Sergey V. Bogorodsky)
10. T. hayashii, Cenderawasih Bay, Indonesia (Mark V. Erdmann)
11. T. tauroculum, Palau (Hiroshi Nagano).
12. T. dalerocheila, Alphonse Island, Seychelles (Jack E. Randall).

Species Included in the Guide:

Trimma abyssum, Trimma agrena, Trimma anaima, Trimma annosum, Trimma anthrenum, Trimma aturirii, Trimma avidori, Trimma barralli, Trimma bathum, Trimma benjamini, Trimma bisella, Trimma blematium, Trimma burridgeae, Trimma caesiura, Trimma cana, Trimma capostriatum, Trimma caudipunctatum, Trimma caudomaculatum, Trimma cheni, Trimma chledophilum, Trimma corallinum, Trimma corerefum, Trimma dalerocheila, Trimma emeryi, Trimma erdmanni, Trimma erwani, Trimma fangi, Trimma fasciatum, Trimma filamentosus, Trimma finistrinum, Trimma fishelsoni, Trimma flammeum, Trimma flavatrum, Trimma flavicaudatum, Trimma fraena, Trimma fucatum, Trimma gigantum, Trimma grammistes, Trimma griffithsi, Trimma habrum, Trimma haima, Trimma haimassum, Trimma halonevum, Trimma hamartium, Trimma hayashii, Trimma helenae, Trimma hoesei, Trimma hollemani, Trimma hotsarihiensis, Trimma imaii, Trimma insularum, Trimma irinae, Trimma kardium, Trimma kitrinum, Trimma kudoi, Trimma lantana, Trimma lutea, Trimma macrophthalmus, Trimma maiandros, Trimma marinae, Trimma matsunoi, Trimma meityae, Trimma mendelssohni, Trimma meranyx, Trimma meristum, Trimma milta, Trimma multiclitellum, Trimma nasa, Trimma nauagium, Trimma naudei, Trimma necopinum, Trimma nomurai, Trimma okinawae, Trimma omanense, Trimma pajama, Trimma papayum, Trimma pentherum, Trimma preclarum, Trimma putrai, Trimma quadrimaculatum, Trimma randalli, Trimma readerae, Trimma rubromaculatum, Trimma sanguinellus, Trimma sheppardi, Trimma sostra, Trimma squamicana, Trimma stobbsi, Trimma striatum, Trimma tauroculum, Trimma taylori, Trimma tevegae, Trimma trioculatum, Trimma unisquame, Trimma volcana, Trimma wangunui, Trimma winchi, Trimma winterbottomi, Trimma woutsi, Trimma xanthochrum, Trimma xanthum, Trimma yanagitai, Trimma yanoi, Trimma yoshinoi, Trimma zurae.