HIGH 



SILVERSIDE 



MUMMICHOG 



Figure 14. Vertical distribution (near 

 surface, midwater, and near bottom) of two 

 most abundant marsh fishes at different 

 tide stages (from Werme 1981). Silver- 

 sides ( Menidia menidia ) are mostly 

 plankton eaters and tend to remain in the 

 open water. Mummichogs ( Fundulus 

 heterocl itus ) hug the bottom and go up 

 into the grass to feed at high tide. 



Figure 15. Mummichog ( Fundulus hetero - 

 cl itus ) is the typical marsh minnow in the 

 New England salt marshes. Mummichogs feed 

 among the bases of Spartina stems and live 

 in the marsh throughout the year, although 

 they bury themselves in the mud in the 

 coldest weather. 



intimately associated with the grassy 

 parts of the regularly flooded marsh. It 

 is probably best known of all the marsh 

 minnows. At low tides, mummichogs lie 

 near the bottoms of creeks, but return 

 toward the grass with flood tides. At 

 high tide, they are found almost entirely 

 within the Spartina (Figure 14). Although 

 mummichogs feed on all sorts of plant 

 material (including algae and detritus), 

 they lack the digestive system required to 

 derive much nutrient value from it 

 (Prinslow et al. 1974). Animals compose a 

 large part of the mummichog diet early in 

 the year; algae constitute the major 

 portion later in the year when animal 

 populations have declined. Over 50% of 

 the diet of 1- to 3-cm long mummichogs 

 is meiofauna (Werme 1981); mummichog young 

 form an important link between the 

 meiofauna they consume and the other fish 

 which consume them. 



Mummichogs spawn beside grass stems 

 and macroalgal clumps at spring tides. 

 The eggs fall into and are hidden in 

 crevices which prevents their being eaten 

 (often by their parents). The eggs attach 

 to plants or other objects by means of 

 adhesive threads. The fry, as well as the 

 adults, are resistant to stresses such as 

 high temperatures or low oxygen levels. 

 Mummichog fry are the minute fish often 

 seen in pools on the marsh surface at low 

 tides. Mummichogs survive winter at the 

 bottoms of the marsh creeks, often in the 

 uppermost, brackish parts of the marsh 

 system, or they may lie semi dormant in the 

 muddy bottoms of marsh pools. 



The striped killifish, the other 

 Fundulus species of New England marshes, 

 is more likely to spend winter in the 

 deeper waters of marsh creeks and 

 associated bays on more sandy bottoms than 

 the mummichog uses. The striped killifish 

 is omnivorous: it consumes more animals, 

 including horseshoe crab eggs, than does 

 the mummichog. It has a longer snout than 

 the mummichog, which enables it to dig 

 deeper into the mud for prey. As a 

 result, killifish guts contain more Gemma 

 gemma and Hydrobia than do mummichog guts. 

 Although they go into the grass at high 

 tide, they take a smaller proportion of 

 their food from the grassy parts of the 

 marsh than does the mummichog. The sand 

 in their guts indicates that they obtain 



24 



