Gobiidae

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 654-656

Cephalic pores and papillae in Gobiidae .

The lateral line system’s canals, pores, and sensory papillae provide important diagnostic characters to distinguish goby genera and species. The figure shows the terminology and notation system used. Canals are stippled, and pores are indicated by Greek letters. It should be noted that there is no lateral line canal on the flank and that the canals may be variously developed on the head. In the species with the most developed canals, there is an anterior oculoscapular canal (from pores ‘s’ to ‘r’), a posterior oculoscapular canal (from pores ‘r1’ to ‘r2’) and a preopercular canal (from pores ‘g’ to ‘e’). One or more of these canals may be absent or interrupted, and the posterior and anterior oculoscapular canals may be continuous or discontinuous. The anterior oculoscapular canals of both sides of the head may be separate or fused in the interorbital area. The anterior oculoscapular canal may be divided into a circumorbital and postorbital segment. The papillae are organised in vertical rows (numbered in Fig. 59 , left) or longitudinal rows (lettered in Fig. 59 , right). To examine the pores and papillae, a dissecting microscope is necessary. They are best viewed using oblique light. On occasion, they may be hidden by mucus. Some authors have attempted to highlight the canals by injecting chromic acid, ferric tannate, or potassium permanganate, but all these methods damage the specimens. Air pulsed by a small aquarium pump through an injection needle is a technique now used by goby specialists. Despite this, goby identification remains challenging even for experts.

Further reading. Sanzo 1911; Miller, in Whitehead et al. 1986 (head canals, pores, and papillae).

Key to genera of gobies in freshwaters in the Black, Caspian, Marmara and Mediterranean basins

1a - 5–13½ branched rays in second dorsal; male with bluish-iridescent blotches on membrane of first dorsal. ………………2

1b - 14–20½ branched rays in second dorsal; male without bluish-iridescent blotches on membrane of first dorsal. ………………3

2a - Male with bluish-iridescent, small blotch on membrane between last and pre-last ray of first dorsal; male without white margins of dorsal, caudal, or anal. ……………… Knipowitschia

2b - Male with bluish-iridescent, small blotches on 1–2nd dorsal membrane of first dorsal; male with a white margin of dorsal, caudal and anal. ……………… Rhinogobius

3a - Anterior naris at end of a tube projecting forward beyond lip; 36–48 total scales in midlateral series. ……………… Proterorhinus

3b - Anterior naris not projecting forward beyond lip; 49–85 total scales in midlateral series. ………………4

4a - 8–10 vertical rows of papillae in suborbital area (Fig. 60b); 72–85 total scales in midlateral series; nape naked. ……………… Mesogobius

4b - 7 vertical rows of papillae in suborbital area (Fig. 60a); 49–74 total scales in midlateral series; nape covered with scales, if nape naked, then 54–65 scales in midlateral series. ………………5

5a - First branched ray of second dorsal about twice as long as penultimate ray; first dorsal with large black spot in posterior part (in N. melanostomus and N. pallasi ). ……………… Neogobius

5b - First branched ray of second dorsal about as long as penultimate ray; first dorsal without large black spot in posterior part. ………………6

6a - Midline of nape naked in front of preoperculum (Fig. 61); diagonal bars on body irregular in position and shape. ……………… Babka

6b - Predorsal area and nape completely covered by scales; no bars on body. ……………… Ponticola

Key to species of freshwater gobies of the Persian Gulf basin and the Arabian Peninsula

1a - Usually more than 1 row of teeth in lower jaw; eye not strongly elevated from head profile. ………………2

1b - Usually only one row of teeth in lower jaw; eye strongly elevated from head profile. ………………6

2a - Upper lip strongly projecting beyond lower lip. ……………… Awaous jayakari

2b - Upper lip not or very slightly projecting beyond lower lip. ………………3

3a - Lower lip clearly projecting beyond upper lip; caudal spade-shaped; flank with 5 blotches along lateral midline; cheek with several rows of pores. ……………… Glossogobius

3b - Lower lip not or very slightly projecting beyond upper lip; caudal roundish; flank mottled or marbled, or with

6–8 irregularly shaped bars or blotches; cheek without rows of pores. ………………4

4a - Male with bluish-iridescent, small blotches on 1–2nd dorsal membrane of first dorsal; orange spot as gill-membrane in male; 5–6 rays in first dorsal. ……………… Rhinogobius sp.

4b - Male without bluish-iridescent, small blotches on 1–2nd dorsal membrane; no orange spot as gill-membrane in male; 7 rays in first dorsal. ………………5

5a - First ray of first dorsal longer than following rays; 9½ rays in second dorsal; 8½ rays in anal. ……………… Bathygobius fuscus

5b - First ray of first dorsal shorter than second ray; 10½ rays in second dorsal; 9½ rays in anal. ……………… Acentrogobius dayi

6a - No canine teeth behind lower jaw symphysis. ……………… Periophthalmus

6b - One large canine tooth behind jaw symphysis and behind row of teeth in lower jaw. ………………7

7a - Barbels present on ventral side of head. ……………… Scartelaos

7b - No barbels on ventral side of head. ……………… Boleophthalmus

Figures

Figure 59. Cephalic lateral line system in gobies (from Kottelat & Freyhof 2007; after Miller in Whitehead et al. 1986).

Proterorhinus