Gastroptychus spinifer ( A. Milne-Edwards, 1880 )

Kilgour, Morgan J. & Shirley, Thomas C., 2014, Reproductive biology of galatheoid and chirostyloid (Crustacea: Decapoda) squat lobsters from the Gulf of Mexico, Zootaxa 3754 (4), pp. 381-419 : 385

Gastroptychus spinifer ( A. Milne-Edwards, 1880)

Gastroptychus spinifer has been previously reported as both Ptychogaster spinifer and Chirostylus spinifer (see Baba et al. 2008) and was the second most common chirostyloid in collections. Gastroptychus spinifer was commonly collected in the Caribbean and Gulf of Mexico from depths of 212 to 2412 m ( Fig. 2 ). This species has previously been reported from near Frederickstadt on the Caribbean island of Santa Cruz ( Baba et al. 2008). Sixtyfour specimens of Gastroptychus spinifer were collected in all months but January and September ( Fig. 3 B): 31 males, 14 females, and 19 ovigerous females were collected. Males ranged in size from 5.8 to 19.8 mm (CW), and the largest specimens were male. Females ranged in size from 7.0 to 16.2 mm; the smallest ovigerous female was 7.9 mm and the largest ovigerous female was 15.7 mm. The CW of ovigerous females and the CW of nonovigerous females were not significantly different (t-test, df = 31, t = -1.103, p = 0.278); the CW of males and females were not significantly different (t-test, df = 62, t = 1.005, p = 0.319). Ovigerous females were not collected in January, February, June, September, November, and December ( Fig. 3 B). Fifteen ovigerous females had egg numbers and sizes measured. The number of eggs ranged from 11 to 117 eggs, with the average egg diameter for each female ranging from 1.19 to 1.76 mm. Fecundity was correlated with CW (R2 = 0.559, p = 0.001) ( Fig. 4 A). Egg size was also correlated with CW (R2 = 0.275, p = 0.045), but the relationship was not robust.

Figures

FIGURE 2. Distribution of each species of the Chirostylidae and Eumunididae used in analysis. Each symbol is a collection location and different species (see legend).

FIGURE 3. Number of specimens of each species collected for each month. Gray bars are males, white bars are females, and black bars are ovigerous females.

FIGURE 4. Linear regression of carapace width and the number of eggs for Gastroptychus spinifer (A. Milne-Edwards, 1880) (A), Eumunida picta Smith, 1883 (B), Munida flinti Benedict, 1902 (C), Munida forceps A. Milne-Edwards, 1880 (D), Munida miles A. Milne-Edwards, 1880 (E), and Munida pusilla Benedict, 1902 (F). Black dashed lines are the 95 % confidence interval. Dotted lines are 95 % prediction intervals.