Amarinus wolterecki ( Balss, 1934 )

Lagare, Nickel Jean S., Mapi-Ot, Emmarie F., Molina, Ziljih S., Neri, Jemateo B., Nuñeza, Olga M. & Mendoza, Jose Christopher E., 2020, On a collection of freshwater and estuarine crabs (Crustacea: Brachyura) from Mindanao Island, the Philippines, Zootaxa 4868 (3), pp. 301-330 : 304

Amarinus wolterecki ( Balss, 1934)

Fig. 2B

Halicarcinus wolterecki Balss 1934: 181 , figs. 3–5.— Woltereck 1941: 140.— Holthuis 1968: 109.

Amarinus wolterecki, Lucas 1980: 198 .— Chuang & Ng 1994: 86, 87.— Ng & Chuang 1996: 12, fig. 3.

Material examined. 19 males, 6.6 by 7.4 mm—13.6 by 14.1 mm, 1 female, 7.5 by 8.1 mm, 3 females bearing larvae, 7.7 by 8 mm—10 by 9.8 mm, 1 ovig., 8.3 by 8.5 mm ( ZRC; NJL1915154–177 ), Lake Mainit , Surigao del Norte prov., coll. N.J. Lagare, 3, 4 Jun. 2019 .

Remarks. Halicarcinus wolterecki was described by Balss (1934) from 6 specimens (1 adult male, 1 adult female, and 4 juveniles) collected from Lake Mainit, a freshwater lake in the northeastern part of Mindanao. Lucas (1980) subsequently transferred it to a new genus he established, Amarinus (type species: Elamena lacustris Chilton, 1882 ), together with six other freshwater or brackish-water species from the western Pacific. Amarinus wolterecki is one of three species of Amarinus reported from the Philippines (together with A. pumilus Ng & Chuang, 1996 , and A. abatan Naruse, Mendoza & Ng, 2008 ), and the only one from Mindanao. It has not been reported from outside the type locality, Lake Mainit, thus far.

Amarinus wolterecki is also one of the largest species of the genus on record thus far. Balss (1934) recorded the adult male syntype with a CL of 12.7 mm. The largest specimen in the present collection, also a male, has a CL = 14.1 mm. Ovigerous females were smaller (CL = 8.0 mm), with an average egg diameter of 0.6 mm (n=28). The present material from Lake Mainit was collected as by-catch, together with edible freshwater crabs & shrimps (e.g. Mainitia mainitensis (Balss, 1937) and Macrobrachium spp., respectively) by local fishermen using “bubu” fish traps (locally made from bamboo) (NJSL pers. obs.).

Figures

FIGURE 2. Colour photos of recently preserved crabs (dorsal habitus). A, Baptozius vinosus (H. Milne Edwards, 1834), male, 67.4 by 46.7 mm (ZRC), Sibutad, Zamboanga del Norte; B, Amarinus wolterecki (Balss, 1934), male, 13.6 by 14.1 mm (ZRC), Mainit, Surigao del Norte; C, Cardisoma carnifex (Herbst, 1796), male, 67.0 by 56.0 mm (ZRC), Manukan, Zamboanga del Norte; D, Tuerkayana hirtipes (Dana, 1851), female, 57.0 by 53.0 (ZRC), Lianga, Surigao del Sur; E, Bresedium brevipes (De Man, 1889), male, 20.8 by 18.2 mm (ZRC), Maigo, Lanao del Norte; F, Labuanium trapezoideum (H. Milne Edwards, 1837), female, 38.3 by 42.0 mm (ZRC), Oroquieta, Misamis Occidental. Scale bars: 10 mm.