Common names:

* proposed name

Synonyms:

Type catalog (last update: 15/08/2007)

Etymology:
'Periophthalmus' is a compound name from the Greek 'peri' (around), and 'ophthalmôn' (eye), which refers to the wide visual field of these species

the specific name is the native name for this species in Waigeo, Irian Jaya, Indonesia (Lesson, 1831)

Maximum recorded length:
141 mm SL (Murdy, 1989)

Live colouration (Murdy, 1989, based on photo F; pers. obs.: North Sulawesi, Indonesia):
background colour light brown to greyish on head, dorsum and flanks, ventrally paler; small black speckles and larger white speckles on flanks; numerous white spots on snout, cheeks and opercula; 3-6 black to dark brown very irregular saddle-like diagonal bars may be visible on dorsum. D1 membrane dark brown, with numerous white spots in the posterior and proximal portion, a black submarginal stripe, and a white margin; D2 proximally grey to brown with small white spots, a medial dark brown stripe sandwiched by two white stripes, and a red margin; caudal fin dusky, with series of dark brown speckles along rays; anal fin white to orange; pelvic fins hyaline to pinkish; pectoral fins dusky with series of brown speckles on rays

Colouration on preservation (Murdy, 1989; pers. obs.):
background colour dorsally and laterally grey to brown, ventrally paler; white spots on head may be preserved; black speckles on flanks; dark dorsal banded pattern frequently not visible. D1 dark grey to brown with white spots proximally and posteriorly, a black submarginal stripe, and a pale margin; D2 proximally dark brown with whitish flecks, a blackish inframarginal stripe and a pale margin; caudal and pectoral fins dusky with series of dark speckles on rays; pelvic and anal fins hyaline

Diagnosis (Murdy, 1989):
D1 XI-XV; total D2 elements 12-13; total anal fin elements 11-12; longitudinal scale count 66-86; TRDB 18-22; pelvic fins united for about one third of the length of their innermost rays, and with a strong frenum; D1 margin convex; dorsal fins not connected by membrane; colouration traits of D1 and D2.
The genus is yet undefined by synapomorphies

Diet:
Brillet (1984b) studied the habitat and behaviour of P. kalolo from Madagascar: this species is carnivorous (crustaceans and other arthropods). Stebbins & Kalk, 1961 and Macnae & Kalk, 1962 studied the gut content of P. sobrinus (= P. argentilineatus) in Madagascar, finding crustaceans, insects and polychaetes; nonetheless, it is probable that they didn't discriminate between this species and P. kalolo, which are sympatric in this region (Clayton, 1993)

Reproduction:
Brillet (1984a) compared the courtship behaviours of P. kalolo (= P. koelreuteri africanus Eggert) and P. argentilineatus (= P. sobrinus Eggert) from Madagascar, finding them very similar

Ecological notes (pers. obs.: North Sulawesi, Indonesia):
locally abundant in the low intertidal zone, where the influence of the sea is dominant, in full sea water, even on sandy substrates

left: estuary of the small river Bajo, nearby a rocky promontory and behind a coral reef: here P. kalolo was found nearby some stunted trees of Sonneratia alba, where the influence of fresh water was minimal (North Sulawesi, Indonesia)

right: Liang beach, a small stand of Sonneratia alba on sand-mud sediments; also here this species was abundant (Bunaken Is., North Sulawesi, Indonesia)

(photos: G. Polgar, 2005)

Distribution (Murdy, 1989):
recorded from East Africa to Samoa; type locality: Waigeo, Irian Jaya, Indonesia

Remarks:
P. kalolo is frequently mistaken for P.argentilineatus, with which is often sympatric; P. kalolo presents: 1) a strong pelvic frenum, absent in P. argentilineatus; 2) partially fused pelvic fins, completely separated in the other species; 3) a different shape of D1, which has a convex margin in P. kalolo, and a concave or straight margin in P. argentilineatus; and 4) a larger maximum size. Nonetheless, these species are very difficult to discriminate at a distance, especially young individuals. It should also be noted that before Murdy's revision (1989) there was a considerable taxonomic confusion. Even Brillet, who studied these two species in Madagascar for several years, initially thought there was a single species, which he also misidentified as P. koelreuteri Pallas (=P. barbarus). In 1975, after more than eight years from his first publication on this topic, he realised with the help of Prof. Roux that he was actually observing two different species, even if partly ecologically partitioned. According to Brillet (1975), Malgasian specimens of P. koelreuteri africanus Eggert (= P. kalolo) frequently presents a horizontal dark stripe on the operculum, which is absent in P. sobrinus Eggert (= P. argentilineatus). Also Magnus ( 1981) misidentified P. argentilineatus as P. kalolo in East Africa

Photographs of Periophthalmus kalolo:

A-E: specimens of P. kalolo on a sandy beach (photo: N. Giovannini, Walea, Sulawesi, Indonesia, 2007)*; F: an East African specimen (photo: J.E. Randall, Khor Angar, Djibouti, 1977, in Randall 1997; fishbase, 2007); G: another East African specimen ( photo: M.M. Smith, Seychelles, in Smith & Heemstra, 1986); H, I: specimens in aquarium (collected in Bunaken Is., North Sulawesi, Indonesia; photos: G. Polgar, 2007) - * with permission

Drawings of Periophthalmus kalolo:

left: cephalic sensory and nasal pores of Periophthalmus spp.: an= anterior nostril; pn= posterior nostril (modified from Murdy, 1989)* - * with permission